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This study delves into the dynamic characteristics of intelligent arches composed of metal foams, augmented with piezoelectric nanocomposite actuators. These arches are represented within the polar coordinate system, utilizing a higher-order shear and normal deformation theory that eliminates the need for shear correction factors. The structural properties exhibit thickness-dependent variations following predetermined functions. The model operates within a thermal environment and is supported by a Winkler–Pasternak elastic substrate. Hamilton's principle is employed to derive the equations governing the structure's motion. In solving these equations for a scenario with simply supported ends, Fourier series functions are employed as an analytical method. The outcomes are cross-verified against previously published studies with simpler configurations. The investigation explores the impacts of various critical parameters on the dynamic response of the structure. Findings reveal that an increase in pores within the metal foam core decreases the frequency, whereas an increase in the volume fraction of carbon nanotubes has the opposite effect. The primary objective of this study is to design and fabricate more efficient smart structures, through a comprehensive understanding and optimization of the behavior of metal foam arches when integrated with piezoelectric components. [ABSTRACT FROM AUTHOR]

In order to reduce the weight of integrated metal foam skeleton under the double constraints of target thermal and structural reliability indexes, this work proposes a three-dimensional (3D) thermal-structural reliability-based topology optimization (RBTO) method, in which the position uncertainty of the multi-structural-thermal loads is considered. The double reliability index constraints in RBTO are decoupled to a sequence of deterministic topology optimization (DTO) and inverse reliability assessment equivalently, based on performance measure approach (PMA). The inverse most probable failure points (IMPP) required by decoupling sequence are searched by the method of moving components. And the sensitivity required in skeleton topology update and IMPP searching are both quickly evaluated by complete analytical expressions using the adjoint method. Results show that 10.12–16.06% additional weight is introduced by RBTO compared to DTO when reliability index increases from 2 to 3, and the rod lattice topology obtained by RBTO is more complex than DTO. Furthermore, the plate-rod hybrid lattice topology is obtained when the load density increases under constant total loads. In addition, the uneven distribution of the multi-structural-thermal loads affects the structural and thermal failure positions significantly. More material is located below the higher loads and 3D tree-like topology is generated by RBTO, which is beneficial for force and heat redistributing and transferring uniformly. The above methods and findings have extensive application prospects in topology design of metal foam with efficient heat transfer and load-bearing capacity. [ABSTRACT FROM AUTHOR]

This study aims to analytically and numerically investigate the dynamic behavior of clamped foam-filled Y-shaped sandwich beams subjected to low-velocity impact. Using the yield criterion for the foam-filled Y-shaped sandwich structure, a theoretical model is proposed. The bound and the analytical solution of low-velocity impact (LVI) of the foam-filled Y-shaped sandwich beam (FYSB) are obtained. Numerical computations are conducted to study the dynamic behavior of FYSB subjected to LVI. Analytical predications are in agreement with numerical. Subsequently, an in-depth analysis is undertaken employing a theoretical model to discuss the influences of parameters such as the Y-shaped plate angle, impact location, foam strength on the dynamic behavior of the FYSB. It is shown that for the given deflection, the impact force diminishes as the impact location progressively approaches the mid-span, and increases with increasing foam strength, Y-shaped plate angle, face-sheet thickness and striker mass. The analytical model can be used to predict the dynamic response of the FYSB subjected to LVI. [ABSTRACT FROM AUTHOR]

This study introduced a novel numerical modeling for the evaluation of a hybrid heat sink design by replacing the solid fins with aluminum foam fins (AFF) for the same thickness of 2 mm within a phase change material (PCM). This innovation is designed to enhance thermal performance in electronic cooling applications. Heat fluxes of 2, 3, and 4 kW/m2 were applied to the base. The performance has been verified at set point temperatures (SPT) of 60°C, 70°C, and 80°C, encompassing a range relevant to various applications. Different AFF thicknesses (4 and 6 mm) and foam porosities (0.85, 0.90, and 0.95) were investigated. The study demonstrated that AFFs improve heat transfer by increasing fin surface area and by effectively raising the thermal conductivity of the PCM. Compared to the SF heat sink, the results show that the AFF design extended the operational time by 5%–8% for the range of heat fluxes. Notably, AFFs with a thickness of 6 mm achieved a significant 41% improvement in the operation time at a lower SPT (60°C). The metal foam porosity of ε = 0.85 exhibited superior thermal performance within the investigated temperature range. This research paves the way for optimizing hybrid heat sink designs using metal foam for efficient thermal management and reduction of weight. [ABSTRACT FROM AUTHOR]

• New data of jet impingement boiling on surface modified metal foam were obtained. • Effects of metal foam wettability on boiling heat transfer were analyzed. • Influence on bubble dynamics behavior was analyzed. • New heat transfer coefficient correlation considering wettability was developed. Wettability may have significant influence on jet impingement boiling on metal foam, but the effect mechanism of metal foam wettability remains unclear. In this study, the boiling heat transfer characteristics of distributed jet array impingement on hydrophobic and hydrophilic metal foam covers were experimentally researched and compared with those on uncoated metal foam covers to analyze the influence of wettability. The experimental conditions cover contact angles of 14.0–158.7°, pore densities of 20–40 PPI, porosities of 92 %-97 %, thicknesses of 3.0–5.0 mm, and jet velocities of 0.5–4.0 m·s−1. The results show that, the obtained maximum heat flux and maximum heat transfer coefficient are up to 538.1 W cm−2 and 57.9 Kw m−2 K−1, respectively; the hydrophobic metal foam cover has a 4.8 K lower surface superheated degree at the onset of nucleate boiling, but a 7.5 % lower maximum heat transfer coefficient compared with the uncoated one; the hydrophilic metal foam cover shows a less deterioration after the departure from nucleate boiling but a 5.3 K higher surface superheated degree at the onset of nucleate boiling than those of the uncoated one. A new correlation for boiling heat transfer coefficients was developed with a mean relative error of 9.75 %. [ABSTRACT FROM AUTHOR]

Heterostructured design and microcrack management mitigate the strength-ductility dilemma in metallic materials. Here, we demonstrate a simultaneous enhancement of strength and ductility in graphene-decorated bimodal pure nickel, achieving a strength increase to 1 GPa and an 18% improvement in elongation by designing heterostructure with graphene, metal powders, and metal foams. The results show that grain refinement, hetero-deformation-induced hardening, and activated stacking faults mainly cause the strength-ductility synergy. Additionally, while dispersed microcracks nucleate within the fine grain zones, their propagation is constrained by the coarse grain zones. This study provides new insights into improving the strength-ductility combination in metallic materials. [ABSTRACT FROM AUTHOR]

The study investigated the deflagration and detonation suppression effect by different thicknesses of metal foam. The results show that the gas explosion suppression effect of metal foam is related to the explosion stage and the metal foam thickness. In the deflagration stage, the flame could be quenched by 10 mm, 20 mm, and 30 mm thick metal foam. In the flame acceleration stage, the flame can only be quenched by the 30 mm thick metal foam. In the detonation stage, detonation could be completely quenched by 20 mm or 30 mm thick metal foam. Ten-millimeter-thick metal foam could make detonation stage convert into deflagration stage and overpressure decreases obviously. Different propagation mechanisms of deflagration and detonation lead to different suppression effects of foam metal. [ABSTRACT FROM AUTHOR]

In this work, a numerical evaluation of the melting/solidification performance of phase change material (PCM) filled inside a triplex‐tube latent heat storage unit has been carried out. To enhance the melting/solidification performance, the porous Cu metal foam (MF) was embedded inside PCM (termed as composite PCM). Alternative segments of pure PCM and composite PCM have been allocated in such a way that both the pure PCM and composite PCM occupy the equal annular area (i.e., equal volumes). Influence of increasing number of segments was delineated on the melting/solidification rate, complete melting time, and thermal energy storage/recovery enhancement. The comparisons were drawn with reference to the model having two segments of PCM and composite PCM. The results show that the model containing 64 segments with alternate allocations of PCM and composite PCM has a faster melting/solidification rate than other models. With 32 alternate segments of MF, the full melting/solidification time reduced by 23%/77% with respect to the case with one segment of MF only. The melting/solidification performance gets saturated beyond 32 segments (M‐5) and negligible variation (only ~1%) in the thermal performance was noticed upon further segmentation. Finally, the model M‐5 proved as the best model considering the aspects of augmented melting/solidification rate and associated complexities. Moreover, the heterogeneity of MF applied in 32‐segment model confirmed that the anisotropic MF results in an increased melting rate and leads over other random isotropic distributions of MF. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) and their composites are gaining popularity due to their exceptional strength qualities. It is well known that adding CNTs to metal foam composites boosts compressive strength. On the other hand CNT addition is still a costly process due to high cost of the CNTs. This study presents a novel and cost-effective solution by selectively adding CNTs to the structurally weakest regions of aluminum foam materials produced via powder metallurgy, employing a newly developed focused multi-step additive method. The cell borders of aluminum foam are strengthened with multiple spherical layers of CNTs, using a transfer method by initially coating the space holders used at the foaming process. The strength increase effect of this CNT addition method was compared with the widely known aluminum foam production parameters via a 4-parameter design of experiment (DOE) study. Compressive strength values of the samples were evaluated using a constant speed compression test acc. to ISO13314. The compacting pressure, CNT concentration, sintering temperature, and sintering period were chosen as DOE parameters, and 78% of the interactions effecting on final compressive strength could be explained with the model. As a result, it was established that, compared to the other parameters, sintering duration had the highest influence on compressive strength. But besides It has also been shown that adding 0.53% CNT by weight only to the cell border regions increases overall strength by 9%. This weight-strength increase ratio is compared with similar studies in the literature and found to be providing a production cost advantage due to the lower amount of CNT addition requirement for the comparable weight relative strength increase. Focused strength increase method has potential to enable controlled failure of foam materials by selectively strengthening strength critical areas of a component. [ABSTRACT FROM AUTHOR]

Metal hydrides provide a safe and efficient way to store hydrogen. However, current metal hydride storage systems, i.e., hydrides incorporated within a storage tank, are far from efficient. Depending on the design, (dis)charging rates may be very long. However, this can be significantly improved by implementing strategies tackling the issue of heat management at the level of: i) the metal hydride bed, and ii) the overall storage system design. This review summarises recent progress in tackling heat management of hydride systems. In this respect, modeling has emerged as a powerful tool. In particular, simulation results show that the compaction of hydride powders with binders and the use of metal foams are both effective in lifting the poor thermal conductivity of hydride beds. For tank designs, cylindrical shapes remain the preferred choice because of the flexibility and ease of supplementing heat management with fins and tubular heat exchangers. The addition of phase change materials to the hydride tank can lead to further heat storage, but any add‐on to simple hydride tanks can only lead to cumbersome systems. It is still a fine art to tune the thermal conductivity of hydride beds while selecting a suitable metal hydride alloy composition. [ABSTRACT FROM AUTHOR]

AbstractThis study examines active vibration control (AVC) in a truncated conical shell composed of metal foam reinforced with agglomerated graphene nanoplatelets and integrated with piezoelectric layers functioning as sensors and actuators. Both complete and partial agglomeration states are considered based on the Eshelby–Mori–Tanaka approach, and the mechanical properties of the porous core are characterized using a closed-cell metal foam model. The governing equations of motion are derived using Hamilton’s principle, based on the two-dimensional axisymmetric elasticity theory, and solved through the finite element method coupled with the Newmark method. Vibration mitigation is achieved using a fractional-order fuzzy proportional–integral–derivative (PID) controller. A comprehensive parametric study is conducted, examining the effects of geometric dimensions, various boundary conditions, reinforcement parameters (including weight fraction, distribution patterns, and agglomeration parameters), and porosity parameters (including pore size, and porosity pattern) on the vibration properties of the shell. Numerical simulations are performed to assess the effectiveness of the proposed AVC system in reducing structural vibrations compared to a constant velocity feedback control approach. The velocity feedback controller reduced central deflection from 12.65 to 5.089 μm, while a fractional-order fuzzy PID controller further improved it to 2.348 μm, representing a 53.86% enhancement over the velocity feedback controller. [ABSTRACT FROM AUTHOR]

Cu aerogel is an ideal material as the X‐ray backlight target in laser diagnosis experiments owing to its porous structure and K‐shell X‐ray emission spectrum. However, because of their poor formability and oxidation resistance, the preparation of pure Cu aerogels with nanoscale particles and pores is still difficult. In this study, a Cu aerogel is fabricated by reducing nanoporous Cu‐based aerogels and assembling Cu nanoparticles. Numerous pores ranging from 1 to 10 nm are present in the Cu aerogel, resulting in a spongy Cu aerogel for integral heating. Meanwhile, a metal passivation process is integrated into the fabrication process to prevent the oxidation of the Cu aerogel. The prepared Cu aerogel is then applied to the Shenguang‐II facility, improving integral heating when irradiated under high‐energy laser pulse irradiation. Compared with the high‐purity Cu foil reference target, the Cu aerogel target emitted nearly 18% more X‐ray energy on the K‐shell, and the noise in the L‐shell spectrum of Cu aerogel is largely restrained. These results indicate that the Cu aerogel is beneficial for the laser diagnostic experiments and essential for the X‐ray radiography in inertial confinement fusion experiments. [ABSTRACT FROM AUTHOR]

This study explores the simulation and analysis of the infiltration process for manufacturing A356 aluminum alloy foams using vacuum pressure. The infiltration technique, known for its versatility in liquid-state metal processing, is widely employed for metal foam production due to its ease of application. The study investigates the relationship between the geometric parameters of the preform, system pressure, and filling times, revealing a correlation. The simulation using the Flow 3D software determines the pressure and vacuum time required to achieve successful aluminum foam without filling failures. Experimental validation through infiltration casting using NaCl as a removable preform aligns with the simulated results, yielding high-quality aluminum foam samples with diverse pore sizes (0.5 mm, 1.0 mm, and 2.0 mm), uniform and interconnected pore distribution, average porosity percentages of 65%, and a relative density of 0.35. The research contributes insights into optimizing the infiltration process for aluminum foam fabrication, bridging the gap in limited literature on cellular metals. [ABSTRACT FROM AUTHOR]

The compressive behavior is one of the most fundamental mechanical properties for engineering materials. In this paper, the octahedral structure model of porous materials is used to evolve the mechanical analysis model under compressive loading for the porous composite materials, which are resulted from reticular metal foams with pore struts presenting multilayered structure. Starting from this analysis model, some fundamental mechanical relationships, including those of the safe load-bearing and overall strength, have been deduced for these porous composite materials. The compressive strength has been characterized for the porous composite body, corresponding to the overall failure caused by the prior breakage of the strut core and by the prior breakage of the strut shell, respectively. The nickel foam products manufactured on the production line of enterprise were used to make porous composite materials by coating the pore struts with epoxy resin, and the metal foam composite material was obtained with the composite pore-struts of metal/resin multilayered structure. Using this porous composite material for compression experiments, it is found that the experimental data match well with the mathematical relationship from the present theoretical model. The results verify the feasibility of this analysis model and the practicality of the relevant mathematical relationship. [ABSTRACT FROM AUTHOR]

To enhance the energy-absorbing capacity of the energy absorber, the circular metal foam-filled tube (CMFFT) under external inversion over a circular die is designed. According to the rule of energy conservation, a theoretical model for the inversion of the CMFFT over a circular die is proposed, considering the radial bending of the CMFFT and the circumferential expansion of the CMFFT in the contact region and disengaging region, and the foam compression. Then, the die inversion deformation of the CMFFT under axial compression is investigated by the commercial software ABAQUS/Explicit. It is seen that the analytical model captures the numerical results reasonably. Next, the influences of the strength of the metal filled foam, the circular corner radius of the die, the average radius of the metal circular tube and the wall thickness of the metal circular tube are discussed. It is found that the force increases with the strength of the metal filled foam and the average radius of the metal circular tube. In addition, the force firstly decreases and then increases with the increase of the radius of the circular die and the wall thickness of the metal circular tube. The absorbed energy increases with the wall thickness of the metal circular tube, the circular corner radius of the die, the average radius of the metal circular tube, and the strength of the metal filled foam. The optimum radius of the circular die is proposed based on the theoretical model. The special energy absorption (SEA) efficiency of the CMFFT under external inversion over a circular die is significantly better than the metal empty tube. The SEA ratio of the CMFFT is 130.21%, when the compressive strength of metal filled foam σ ¯ F = 0.0694 . It is demonstrated that the CMFFT under external inversion over a die is a good energy absorber. [ABSTRACT FROM AUTHOR]

An experimental investigation was carried out on high porosity metal foams subjected to array jet impingement with an objective to develop enhanced heat transfer configurations. In this study, we propose an integrated thermal management system (TMS) aimed toward leveraging the conjugate heat transfer capabilities of target plate, metal foam, and the jet plate--all made from aluminum and assembled such that a proper contact between them can be established. Steady-state heat transfer experiments were carried out for 10 and 20 pores per inch (PPI) aluminum foams of 0.93 porosity. Both metal foams were 12.7-mm thick. The normalized jet-to-jet spacing was varied from 2 to 12 times the jet diameter, while the jet diameter was fixed. The ratio of the jet plate thickness and jet diameter (nozzle aspect ratio) was 6.35, which ensured proper development of jets inside the nozzles. Experiments were conducted over a wide range of Reynolds number (based on jet diameter) varied from 100 to 5000. The obtained convective heat transfer coefficient for different configuration was evaluated in context with pressure drop. The analysis of experimental results reveal that large open area ratio jets combined with high porosity metal foams provide highly efficient and high-performance cooling for the investigated range of Reynolds numbers. [ABSTRACT FROM AUTHOR]

A barium-rich Celestine (Sr,Ba)SO4 concentrate from the primary Mexican ore production was used as a thickening agent to produce closed-cell Zn-22Al-2Cu alloy foams, while calcium carbonate was used as a foaming agent. The microstructure and mechanical properties of the foams were analyzed by optical microscopy, scanning electron microscopy, and compression tests, respectively. The Zn-22Al-2Cu alloy foams showed a typical lamellar eutectic microstructure, constituted by a zinc-rich phase (η) and a (α) solid solution that was richer in aluminum, while a copper-rich (ε) phase was formed in the interdendritic regions. The SEM micrographs show the presence of small particles and aggregates that are randomly scattered in the cell walls and correspond to unreacted calcite and Celestine–Barian particles, especially for the higher barite addition. The compressive curves showed smooth behavior, wherein the particles at the cell walls did not affect the foam's compressive behavior. The trial containing 1.5 wt. % of BaSO4 and 1.0 wt. % of CaCO3 showed a higher energy absorption capacity of 5.64 MJ m−3 because of its highest relative density and lowest porosity values. The Celestine–Barian concentrate could be used as a foaming agent for high melt-point metals or alloys based on the TGA results. [ABSTRACT FROM AUTHOR]

In this work, theoretical and numerical studies of the dynamic response of a fiber–metal laminate (FML) sandwich beam under uniform blast loading are conducted. On the basis of a modified rigid-plastic material model, the analytical solutions for the maximum deflection and the structural response time of FML sandwich beams with metal foam core are obtained. Finite element analysis is carried out by using ABAQUS software, and the numerical simulations corroborate the analytical predictions effectively. The study further examines the impact of the metal volume fraction, the metal strength factor between the metal layer and the composite material layer, the foam strength factor of the metal foam core to the composite material layer, and the foam density factor on the structural response. Findings reveal that these parameters influence the dynamic response of fiber–metal laminate (FML) sandwich beams to varying degrees. The developed analytical model demonstrates its capability to accurately forecast the dynamic behavior of fiber–metal laminate (FML) sandwich beams under uniform blast loading. The theoretical model in this article is a simplified model and cannot consider details such as damage, debonding, and the influence of layer angles in experiments. It is necessary to establish a refined theoretical model that can consider the microstructure and failure of composite materials in the future. [ABSTRACT FROM AUTHOR]

Metallic foams exhibit unique properties that make them suitable for diverse engineering applications. Accurate mechanical characterization is essential for assessing their performance under both monotonic and cyclic loading conditions. However, despite the advancements, the understanding of cyclic load responses in metallic foams has been limited. This study aims to propose a mesostructural model to assess the fatigue behavior of open-cell metal foams subjected to cyclic loading conditions. The proposed model considers the previous load history and is based on the analogy of progressive collapse, integrating a finite element model, a fatigue analysis model, an equivalent number of cycles model, and a failure criterion model. Validation against experimental data shows that the proposed model can reliably predict the fatigue life of the metallic foams for specific strain amplitudes. [ABSTRACT FROM AUTHOR]

The effects of different configurations of a metal foam flow field on current density and temperature gradient of a single channel solid oxide fuel cell (SOFC) are investigated, and the overall performance of the optimum configuration is optimized. First, model A (conventional channel-rib flow field) is compared with three different configurations (i.e., model B with metal foam flow field only at anode, model C with that only at cathode, and model D at both). Although model C achieves the highest current density, its temperature is also fairly high. Although model B achieves the lowest temperature gradient, its current density is also fairly low. Model D performs well in both current density and temperature gradient. Then, the effect of electrode thickness and metal foam thickness on the performance of model D is investigated. The Ohmic polarization of model D remains almost constant with different electrode thicknesses, and its concentration polarization decreases as the electrode thickness decreases, which is totally different from the channel-rib flow field. Moreover, a thinner cathode causes lower activation overpotential, whereas a thinner anode causes higher activation overpotential. In general, a thick anode, a thin cathode, and thin metal foam can maximize the current density of model D, while a thick electrode and metal foam can always reduce the temperature gradient. Finally, the Taguchi method and gray relational analysis are used to optimize the current density and temperature gradient of model D. The current density of an optimized model is 3.27% higher than that of the original model with a temperature gradient of 9.05 K/cm. [ABSTRACT FROM AUTHOR]

This study presents numerical findings on the flow and heat transfer irreversibility when metal foams are partially filled in a horizontal pipe. A heater is embedded in the pipe's circumference with a known heat input. Aluminum metal foam, characterized by a pore density of 10 and porosity of 0.95, is placed next to the inner wall of the pipe to enhance heat transfer. To determine the optimal thickness of the metal foam for thermodynamic performance enhancement, metal foams of five different thicknesses (10–80 mm) are examined under forced convection heat transfer conditions. The study integrates the Darcy Extended Forchheimer and local thermal nonequilibrium models to predict flow and heat transfer characteristics through the metal foams. Validation of the numerical methodology is conducted by comparing the results with experimental data available in the literature. A novel aspect of this investigation is the application of the second law of thermodynamics to analyze the thermodynamic performance of metal foams. Exergy and irreversibility analyses are used to evaluate the thermodynamic performance, revealing that a pipe filled with metal foams up to a thickness of 40 mm exhibits superior thermodynamic performance compared to other cases examined in the study. [ABSTRACT FROM AUTHOR]

The need for high speed and reduction in size in electronic components leads to a rise in the power dissipation needed for thermal management. In this research, experiments have been carried out to examine the thermal efficiency from heat sink located on an energy source in a channel. A total of 4 test models with different shapes were tested. Model 1 conventional heat sinks is made from aluminum, model 2 fin heat sinks is made from metal foam, model 3 plate heat sink is made from metal foam and model 4 fin heat sinks filled space between the fins with metal foam; all models have the same flat plate surface area. Copper metal foam of constant pore density of 40 PPI and constant porosity of 0.91 were used. The test runs are done at the air flow rates ranging between (1.2 to 3.3) m/s with the inlet air temperature is 27 °C. The outcomes revealed that the model 3 heat sinks have a greater heat transfer coefficient and a lower thermal resistance than the other types of heatsinks. At input velocity of 3.3 m/s and high power of 30 W, model 3 has the best Nusselt number ratio it has increased from models 2 and 4 by 13.7% and 6.8%, respectively. The plate foam heat sink model 3 has a larger pressure drop when compared to conventional fin heat sink model 1. Moreover, the pressure drop between Models 2 and Model 4 is not significantly different. Additionally, at higher flow rates, the model 3 heat sinks show a 22% reduction in thermal resistance compared to the model 1 at a power of 30 W. [ABSTRACT FROM AUTHOR]

Lately, metal foams have been widely used in various engineering structures due to their exceptional mechanical properties, including their lightweight. However, scientists have proposed adding nano-fillers like graphene nanoplatelets (GNPs) to overcome the issue of low stiffness caused by increased porosity. Hence, aerodynamic stability and vibrational behaviors of nanocomposite metal foams (NCMF)-reinforced GNPs sector microplate with piezoelectric/metallic face sheets are provided in this work. The microstructure is sited on Kerr elastic substrate and also is in a hygro-thermo-electrical media, subjected to supersonic flow based on first-order piston's theory (FPT). Gaussian random field (GRF), Halpin-Tsai, and extended rule of mixture (ERM) in conjunction with Gurtin-Morduch, modified strain gradient theories, and Hamilton's principle are used to derive the governing equations and linked boundary conditions. Generalized differential quadrature (GDQ) scheme is chosen to attain the results. By validating the results' precision, the effects of different parameters on the natural frequencies (NFs) and critical aerodynamic pressures (CAPs) are observed. It is perceived that adding GNPs enhances both NFs and CAPs significantly, and increasing porosity up to seventy percent, leads the results to drop. Various industries use simpler models to evaluate the microstructure, therefore the present model can pave the way for future uses and push the boundaries of knowledge in these industries based on the results it produces. [ABSTRACT FROM AUTHOR]

• 3D ice storage spheres with different metal foam methods and proportions are designed. • Solidification performance of PCMs augmented by partially metal foam is studied. • The competitive mechanism of natural convection and heat conduction is analyzed. • Considering the economic benefit, the optimal filling radius 6/13 is obtained. The advancement of ice-ball thermal energy storage systems is limited by the poor thermal conductivity of phase change materials(PCM). This paper presents a numerical investigation into enhancing heat transfer in ice balls by partially filling them with metal foam. Dynamic temperature changes, solid phase fraction, and cold storage capacity are analyzed for various filling radius ratios (2/13, 4/13, 6/13, 8/13, and 13/13). We quantitatively assess the specific impact of metal foam filling on heat transfer by calculating changes in the comprehensive thermal conductivity coefficient. Our findings reveal that the comprehensive thermal conductivity coefficient increases nonlinearly with the growing metal foam filling radius ratio, indicating that full filling may not the most optimal configuration. Furthermore, the energy storage capacity per unit time, per unit weight and per unit cost of the ice ball filled with metal foam under different radius ratios was evaluated by comprehensive evaluation criteria, and the optimal filling radius ratio was determined to be 6/13. Contrary to prior findings, this research highlights the efficacy of partial filling strategies, offering valuable insights for optimizing ice ball performance in thermal energy storage applications. [ABSTRACT FROM AUTHOR]

Recent industrial explosions globally have intensified the focus in mechanical engineering on designing infrastructure systems and networks capable of withstanding blast loading. Initially centered on high-profile facilities such as embassies and petrochemical plants, this concern now extends to a wider array of infrastructures and facilities. Engineers and scholars increasingly prioritize structural safety against explosions, particularly to prevent disproportionate collapse and damage to nearby structures. Urbanization has further amplified the reliance on oil and gas pipelines, making them vital for urban life and prime targets for terrorist activities. Consequently, there is a growing imperative for computational engineering solutions to tackle blast loading on pipelines and mitigate associated risks to avert disasters. In this study, an empty pipe model was successfully validated under contact blast conditions using Abaqus software, a powerful tool in mechanical engineering for simulating blast effects on buried pipelines. Employing a Eulerian-Lagrangian computational fluid dynamics approach, the investigation extended to above-surface and below-surface blasts at standoff distances of 25 and 50 mm. Material descriptions in the numerical model relied on Abaqus' default mechanical models. Comparative analysis revealed varying pipe performance, with deformation decreasing as explosion-to-pipe distance increased. The explosion's location relative to the pipe surface notably influenced deformation levels, a key finding highlighted in the study. Moreover, quantitative findings indicated varying ratios of plastic dissipation energy (PDE) for different blast scenarios compared to the contact blast (P0). Specifically, P1 (25 mm subsurface blast) and P2 (50 mm subsurface blast) showed approximately 24.07% and 14.77% of P0's PDE, respectively, while P3 (25 mm above-surface blast) and P4 (50 mm above-surface blast) exhibited lower PDE values, accounting for about 18.08% and 9.67% of P0's PDE, respectively. Utilising energy-absorbing materials such as thin coatings of ultra-high-strength concrete, metallic foams, carbon fiber-reinforced polymer wraps, and others on the pipeline to effectively mitigate blast damage is recommended. This research contributes to the advancement of mechanical engineering by providing insights and solutions crucial for enhancing the resilience and safety of underground pipelines in the face of blast events. [ABSTRACT FROM AUTHOR]

The present article is focused on the condensation process of exhaust gases to reduce the air pollution to a possible extent. It is accomplished by circulating liquid N2 through copper tubes inside a chamber that is designed to condense the oncoming exhaust gases from the muffler of automobiles, thereby condensing a significant portion of exhaust gases. The condensed gases can be stored and processed at any industrial premises for recycling in a cost-effective manner. The work reported herein compares the design and analysis of two different mechanisms to achieve the effective condensation of automobile exhausts (i.e.)., one involves the employment of copper tubes with Liquid N2, and other involves porous bed kept inside copper tubes with Liquid N2. It is observed that a significant improvement in the heat transfer characteristics of the later version with porous bed over the other counterpart. The modelling and meshing of copper tubes with porous material is a tedious process, because it requires a huge number of nodes to capture the geometry. Hence, the non-equilibrium porous bed module available in the ANSYS Fluent tool is used to carry out the numerical analysis of the entire model. Further, the performance characteristics of the porous bed model are validated with a small sectional model of copper tube with porous bed and by a novel experimental technique involving distilled water in copper tubes. The outcomes of the studies are presented with different colour band metrics and trial experimental results. [ABSTRACT FROM AUTHOR]

We study shock recompression of the metal spall fracture region using macroscopic simulations in a wide range of initial parameters. Recompression states are mainly analyzed based on different simulation methods. First, we employ an empirical numerical treatment within the fracture post-processing model, resulting in a good agreement with experimental data of porous metals. To further validate its applicability, we carry out direct simulations that distinguish various initial fractured states, and we find that the influence of an initial fractured state on the recompression state is remarkable, especially the temperature. By comparing recompression states calculated by two different simulation methods, it reveals that empirical-treatment-based simulations actually describe fragment-state recompression. The present study shows that empirical-treatment-based simulations are physically capable of describing the shock recompression of fractured metals, which might be potentially used to investigate detonation-driven experiments with more complicated physical scenarios. [ABSTRACT FROM AUTHOR]

The liquid metal dealloying (LMD) process enables the fabrication of porous metals with various chemical compositions. Despite its advantages, LMD still faces key challenges such as maintaining the high‐temperature molten metal bath for a prolonged time, avoiding the use of toxic etchants, and so on. To overcome these challenges, the study develops a water‐leachable and oxidation‐resistant alloy melt (AM) in Ca‐Mg binary system. Specifically, Ca72Mg28 eutectic AM is designed, which exhibits higher oxidation resistance and lower melting temperature compared to pure Mg, allowing LMD to be conducted in atmospheric conditions as well as temperatures >200 K lower. The AM also enables an innovative process to fabricate Ti foams with a hexagonal faceted surface structure by carefully manipulating the etching rate during the water etching process. This approach allows for the creation of foam with a surface area over 13% larger than that of foams with smooth surfaces via normal acid etching, potentially enhancing efficiency in applications such as electrodes for electrochemical systems or biomedical materials where increased cell adhesion can be beneficial. This study paves the way for efficiently manipulating the LMD process to fabricate metal foams with customized compositions and enhanced surface properties. [ABSTRACT FROM AUTHOR]

This study investigates tube-in-tube heat exchanger performance under steady-state conditions, examining co-current and counter-current flows. It explores various configurations, including metal foam enhancements, to optimize heat transfer efficiency and minimize pressure drop. Driven by the potential of metal foam to enhance heat transfer, the study aims to demonstrate significant improvements in thermal performance compared to conventional designs. Experimental methods involve testing four configurations with Nickel foam (10 PPI, 0.90 porosity) inserts, evaluating temperatures and pressure drops across flow rates of 25 to 50 LPH. Hot water at 65°C flows in the annulus, while normal water at 31°C flows in the outer annulus. Results show metal foam’s substantial enhancement in heat transfer, with counter-current metal foam configurations achieving up to 3.71 times greater efficiency than parallel flow setups. Moreover, comprehensive performance evaluation reveals that the counter-flow heat exchanger with metal foam is 2.03 times more efficient than the conventional co-current flow without metal foam. Conclusions highlight metal foam’s effectiveness in improving heat transfer performance and optimizing thermal systems through systematic parameter optimization using response surface methodology. [ABSTRACT FROM AUTHOR]

This investigation studies a rectangular slot jet impingement on a copper foam flat plate numerically. The current paper studied the effect of copper foam's thickness and pore density on heat transfer characteristics using the ANSYS Fluent package. Simulation is conducted for Reynolds number (Re), which varies between 5200 and 14000, and slot-to-plate distance (z/b), which varies between 2 and 8. The copper foams have a porosity of 90%, thicknesses of 4, 8, and 12 mm, and pore densities of 10, 20, 30, and 40 PPI. The local Nusselt number (Nu) and average Nusselt number $(\overline{N u})$ of the copper foam flat surface are better than the smooth flat surface, regardless of the thickness and pore density of the copper foam. The Nu and $\overline{N u}$ of a copper foam flat surface for a thickness of 4 mm provide higher augmentation than those for 8 mm and 12 mm thicknesses. The Nu and $\overline{N u}$ of the copper foam flat surface of 10 PPI provide a higher augmentation than the copper foam flat surfaces of 20 PPI, 30 PPI, and 40 PPI. The influence of slot-to-plate distance on the Nu of the target surface is studied. For the case of the smooth flat surface, the Nu slightly increased with the increment of the slot-to-plate distance. In the case of the copper foam flat surface, the effect of slot-to-plate distance on Nu and $\overline{N u}$ is dependent on the thickness of the copper foam. The influence of the thickness of copper foam on jet velocity and the total pressure distribution were discussed in detail using the numerical model. [ABSTRACT FROM AUTHOR]

This work presents the vibration and buckling analyses for a sandwich arch with Titanium alloy face sheets and a metal foam core via a new porosity-dependent model. Porous aluminum core consists of six layers so that each of them reinforce by graphene platelets (GPLs) with different values of porosity to achieve a piece-wise functionally graded media. The mathematical modelling is formulated to reveal nonlinear responses of the porous sandwich arch embedded in an elastic nonlinear medium. The higher-order equations of motion are achieved by taking Hamilton's principle within the framework of the von Kármán nonlinear hypothesis. Afterwards, the established nonlinear problems are solved analytically with the aid of a perturbation-based technique implementing the Galerkin procedure. The investigation results show effects of the weight fraction of GPLs, porosity distribution, geometrical characters and foundation stiffness on nonlinear vibration and buckling of the porous sandwich arch. [ABSTRACT FROM AUTHOR]

This research investigates the use of metal foam inserts to enhance the thermal-hydraulic performance of double-tube heat exchangers, relevant for energy-efficient systems such as solar flat plate collectors. Motivated by the need for improved heat transfer efficiency, this study hypothesizes that metal foam integration can significantly boost performance. Through systematic experimental study, the impact of metal foam inserts on heat transfer and pressure drop characteristics is comprehensively evaluated across various configurations, spanning horizontal and vertical orientations. Experimental evaluations were conducted on four configurations, including both conventional and metal foam-integrated heat exchangers in horizontal and vertical orientations, using water as the working fluid and Nickel metal foam with 0.9 porosity and 10 PPI in the annular space. The findings highlight significant enhancements in heat transfer performance with metal foam integration across both horizontal and vertical heat exchanger configurations compared to conventional counterparts, particularly showcasing superior effectiveness and efficiency in the horizontal configuration. Results show that metal foam integration substantially enhances heat transfer, with horizontal configurations exhibiting a 14.56% higher heat transfer coefficient than vertical ones. Additionally, the comprehensive performance index improved by 1.17 times, indicating a better balance between heat transfer enhancement and pressure loss. These findings were validated against established correlations from the literature, confirming the superior effectiveness of horizontal metal foam heat exchangers. [ABSTRACT FROM AUTHOR]

Latent Heat Transfer Thermal Energy Storage (LHTES) units are crucial in managing the variability of solar energy in solar thermal storage systems. This study explores the effectiveness of strategically placing layers of anisotropic and uniform metal foam (MF) within an LHTES to optimize the melting times of phase-change materials (PCMs) in three different setups. Using the enthalpy–porosity approach and finite element method simulations for fluid dynamics in MF, this research evaluates the impact of the metal foam's anisotropy parameter (Kn) and orientation angle (ω) on thermal performance. The results indicate that the configuration placing the anisotropic MF layer to channel heat towards the lower right corner shortens the phase transition time by 2.72% compared to other setups. Conversely, the middle setup experiences extended melting periods, particularly when ω is at 90°—an increase in Kn from 0.1 to 0.2 cuts the melting time by 4.14%, although it remains the least efficient option. The findings highlight the critical influence of MF anisotropy and the pivotal role of ω = 45°. Angles greater than this significantly increase the liquefaction time, especially at higher Kn values, due to altered thermal conductivity directions. Furthermore, the tactical placement of the anisotropic MF layer significantly boosts thermal efficiency, as evidenced by a 13.12% reduction in the PCM liquefaction time, most notably in configurations with a lower angle orientation. [ABSTRACT FROM AUTHOR]

This paper introduces a novel method for preparing high-performance, metal-containing carbon foam wave-absorbing materials. The process involves foaming glucose through catalysis by transition metals followed by high-temperature pyrolysis. The resulting carbon foam materials exhibit a highly porous structure, which is essential for their wave-absorption properties. Notably, at a thickness of 2.0 mm, the glucose-derived carbon foam composite catalyzed by Fe and Co (GCF-CoFe) achieved a minimum reflection loss (RLmin) of −51.4 dB at 15.11 GHz, along with an effective absorption bandwidth (EAB) of 5.20 GHz, spanning from 12.80 GHz to 18.00 GHz. These impressive performance metrics indicate that this approach offers a promising pathway for developing low-density, efficient carbon foam materials for wave-absorption applications. This advancement has significant implications for fields requiring effective electromagnetic interference (EMI) shielding, stealth technology, and other related applications, potentially leading to more efficient and lightweight solutions. [ABSTRACT FROM AUTHOR]

Under lateral load, this article aims to discuss the large deflection and yield criterion of Y-shape sandwich beams filled with foam. Considering the effect of metal foam strength, a yield criterion of Y-shape sandwich structure filled with foam is proposed. An analytical solution for large deflection of clamped foam-filled Y-shape sandwich beam under lateral load is derived using yield criterion, considering the interaction between stretching and bending due to large deflection. The corresponding numerical calculation of sandwich beams under lateral load is carried out. It is shown that the theoretical results are in good agreement with the calculated results. The effects of metal foam strength, face-sheet thickness and punch width on large deflection are studied in detail. The results show that the analytical model could predict the large deflection of foam-filled Y-shaped sandwich beam under lateral load really well. [ABSTRACT FROM AUTHOR]

This research focuses on examining the vibrational properties of intelligent curved microbeams (CMBs) that incorporate metal foams and are enhanced with carbon nanotubes-reinforced piezoelectric (CNTRP) actuators. An advanced four-variable theory for shear and normal deformation is applied in the polar coordinate framework to investigate the microstructure, thereby negating the need for a shear correction factor. Additionally, the modified couple stress theory (MCST) is utilized to account for scale effects. The structural attributes exhibit thickness-dependent alterations following predefined functions. The governing equations of motion are deduced using Hamilton’s principle. In instances where the structure has simply supported ends, Fourier series functions are utilized to solve these equations. The outcomes are cross-validated in contradiction with previously documented works with more straightforward setups. The inquiry investigates the effects of critical parameters on the vibrational response of the structure. The results are corroborated in simpler scenarios using existing data in the literature to ensure accuracy. [ABSTRACT FROM AUTHOR]

High output temperature and photothermal conversion effectiveness were achieved with the absorber platform structure. A novel solar receiver was manufactured to integrate pre-heating and thermal conversion, aiming to enhance heat utilization and output temperature. This work is based on the engineering design and experimental testing of a solar cavity-receiver containing a porous copper foam that can volumetrically absorb high-flux radiation and heat up, through convection with air-flow. The air outlet temperature, outer wall temperature, thermal performance, and efficiency were experimentally determined by pore density, air mass-flow rate and solar irradiance. Additionally, the temperature growth of unit incident power, the unit volume efficiency growth rate, and output temperature were employed to evaluate the thermal conversion characteristics of the endothermic body (copper foam). The results indicated that the air outlet temperatures can reach 500 °C with lower input power. Furthermore, it was found that under a pore density of 30 pores per inch and a flow rate of 60 Lpm, the photothermal conversion efficiency of the absorber with copper foam reached as high as 87.61%, which is 35.04% significantly higher than that of an absorber without copper foam. The manageable solar receiver design proved to deliver a high-temperature air-flow (approximately 500 °C) with a reasonably high thermal efficiency (over 85%). [ABSTRACT FROM AUTHOR]

The influence of metal foam thickness on the convection and conduction heat transfer is studied by measuring the local heat transfer of a smooth flat plate, attached and detached metal foamed flat plate under multiple jet impingement conditions. 27 jets of 3 mm diameter are introduced from a jet plate. These jets impinge on a thin stainless steel foil that serves as a targeted plate. The pitch of the jets is 4d in both the spanwise and streamwise directions. The spent fluid is exiting in all directions. The influence of metal foam thickness is investigated for an open-cell aluminum foam with 4, 8, and 12 mm thickness. The porosity of aluminum metal foam is 0.92. The pore density (pores per inch) is 20 PPI. The local heat transfer is measured using infrared thermography and a thin metal foil technique. A smooth flat plate impinged by multiple jets serves as a reference case. The evaluation of the convection and conduction heat transfer offered by the metal foamed flat plate is obtained with the help of the detached foam configuration. The jet diameter-based Reynolds number ranges from 2500 to 15000. The range of the jet to plate spacing covered is 3d to 6d. Depending on the metal foam thickness, the metal foamed flat plate offers additional hydraulic resistance to the jet flow and conduction effect. The additional hydraulic resistance attenuates the convective heat transfer and is represented by attenuation factor (α). For metal foam having 4, 8, and 12 mm thickness, the attenuation factor is around 1.11, 0.99, and 0.64, respectively. The conduction effect offered by metal foam is responsible for the enhancement of the heat transfer. The conduction effect is represented as an enhancement factor (E). For metal foam having 4, 8, and 12 mm thickness, the enhancement factor is around 1.51, 1.58, and 2.32, respectively. The conduction effect presented in the metal foamed flat plate dominates over the attenuation in the convective heat transfer. The overall enhancement offered by 4, 8, and 12 mm metal foamed flat plate is around 1.67, 1.56, and 1.48, respectively. [ABSTRACT FROM AUTHOR]

Composite metal foams (CMFs) are a new class of closed-cell porous materials that can be produced by distributing metallic spheres in a metallic matrix. CMFs could offer better mechanical performance in comparison to the conventional metal foams due to the uniform shape and even distribution of voids. To evaluate elastic properties of CMFs, the conventional theoretical approaches for periodic models are not good candidates due to the random distribution of voids in these materials. Thus, in this research, first, a three-dimensional model is developed based on the Lubachevsky and Stillinger (LS) approach, which is then used for the FE analysis. Using homogenization technique, the elastic properties of the CMFs are evaluated focusing here on elastic modulus and Poisson's ratio. Comparing results against experimental results shows a very good agreement. In this paper, for the first time, effects of geometrical and material parameters such as thickness of the spheres, microporosity in the wall of spheres and matrix, matrix materials, and diameter of the spheres on the elastic properties of CMFs are examined. It is observed that the microporosity in the matrix has higher effect on the elastic modulus of the CMFs than the microporosity in the wall of the spherical particles. [ABSTRACT FROM AUTHOR]

Nonlinear bending of functionally graded metal/graphene (FGMG) sandwich rectangular plate with metal foam core resting on nonlinear elastic foundations is elucidated in this article. A new shear deformation plate theory is presented to formulate the displacement field. The nonlinear partial differential equations considering the small size effect are established via the principle of virtual work. The nonlinearity is considered by using Von Karman's strain-displacement relations. While, the size effect is captured by employing the modified couple stress theory. The upper and lower layers are made of aluminum as a matrix that reinforced with graphene platelets (GPLs). The GPLs are functionally graded through the thickness of the face layers according to a new cosine rule. Moreover, the metal foam core is also made of aluminum containing porosities that uniformly distributed or functionally graded through the core thickness. The governing equations are solved based on the Galerkin and Newton's methods. The obtained results are examined by introducing some comparison examples. In addition, several parametric examples are discussed including the effects of the porosity type, GPLs distribution type, core-to-face thickness, elastic foundation stiffness, side-to-thickness ratio, plate aspect ratio and material length scale parameter on the nonlinear deflection and stresses of FGMG sandwich plate with metal foam core. [ABSTRACT FROM AUTHOR]

AbstractThe variable thickness function is innovatively added. The carbon fiber layer and the porous foam metal aluminum, are selected to composite the composition of a variable thickness cantilevered trapezoidal plate for modeling and free vibration analysis. Hamilton’s principle is used to develop the motion control equation of the trapezoidal plate with variable thickness cantilevered sandwich, and Galerkin’s approach is used to determine the inherent frequency of the system. The research employs suitable analytical methods to solve them, and analyzes the outcomes to uncover the effects of geometric parameters, material properties, and thickness variations on the structure. [ABSTRACT FROM AUTHOR]

Aluminum foams have emerged as a remarkable engineering material, exhibiting exceptional structural performance and many excellent properties. This has led to a rise in their application in various fields. The investigation and development of aluminum foam have led to the discovery of multiple applications in numerous industries, including the aerospace, automotive, petrochemical, and building materials industries. Foam made of aluminum, one of the most well-known examples of metallic foams, is a significant technological advancement in the foams industry. This article aims to comprehensively analyze the manufacturing techniques that employ blowing agents, such as alumina, titanium hydride, and sodium chloride. This article explores the unique properties and diverse applications of aluminum foams. In addition, the current status of research and development in aluminum foam is discussed. It accomplishes this by providing an overview of existing developments and identifying future opportunities in this industry. This review article is an invaluable resource for academics and industry professionals interested in aluminum foams, as it provides valuable insights into production procedures, properties, applications, and ongoing research. [ABSTRACT FROM AUTHOR]

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This study analyses the heat transfer performance of metal foam heat exchangers through experimental measurements. Using counter-gravity infiltration casting, open-cell aluminium foam elements were manufactured to embed a copper tube for internal mass flow containment. Heat transfer experiments were conducted under natural and forced convection conditions, with the airflow controlled in a wind tunnel. A stream of warm water within the internal foam component served as the heat source, transferring thermal energy to the surrounding air flowing through the external foam component of the heat exchanger. The results showed a significantly enhanced heat transfer performance with aluminium foam compared to a single copper tube. Thermal resistance models were developed to elucidate the heat transfer mechanisms, highlighting the effectiveness of air-cooled metal foam heat exchangers. These findings underscore the potential of metal foam heat exchangers as cost-effective alternatives for various thermal management applications. [ABSTRACT FROM AUTHOR]

Water/oil (W/O) emulsions are formed during oil fields and production development, thereby reducing the oil quality. In order to separate the emulsions, specialists use various methods, equipment, and materials. Most emulsions formed during oil production are stable and persistent, and traditional methods such as sedimentation and centrifugation are ineffective in the separation process. Addressing this challenge, porous materials characterized by selective super-wetting properties are used for the high-quality separation of stable W/O emulsions. Therefore, this review presents recent advancements in highly porous cellular materials that separate W/O emulsions. It further discusses the features, limitations, and advantages of using superhydrophobic/superleophilic and superhydrophilic/superleophobic porous materials such as metallic and polymeric foams. The influence of the structure and nature of porous materials on the efficiency of the separation of W/O emulsions is analyzed. Additionally, this review also explores methods for modifying highly porous materials to improve selective wettability. [ABSTRACT FROM AUTHOR]

Metal foam flow fields are considered as an alternative to conventional channel/rib flow field in polymer electrolyte membrane fuel cell (PEMFC) because of the advantages of three-dimensional pore structure. In this study, the effect of metal foam flow field with different manifold size on PEMFC performance was investigated, with a 25 cm2 unit cell. Polarization curve and electrochemical impedance spectroscopy results were analyzed to investigate the effects of gas stoichiometry and relative humidity on performance. The mass transfer loss was decreased with reduced manifold size. However, mass transfer loss was increased due to difficulty of water discharge in small manifold case. The metal foam flow field offer advantages in water discharge and mass transfer loss. At 100% relative humidity, performance was improved with increased air stoichiometry for different manifold size. At 25% relative humidity, performance was a little improved with increased air stoichiometry for small manifold case. Regardless of relative humidity, fuel cell performance with metal foam flow field was most improved in case of smallest manifold size based on air stoichiometry due to the high pressure drop. • The performances were not proportional to the size of the manifold. • Increasing air stoichiometry, the performance increase was highest for the smallest manifold size. • The mass transfer was mainly influenced by the size of the manifold. [ABSTRACT FROM AUTHOR]

AbstractA novel porous multi-jet impingement cooling technology since the current conventional cooling technologies are insufficient for thermal engineering devices. This innovative numerical study explores the effect of various metal foam sizes (h/H), jet numbers (n) and wavy jet target plates (C) on the hydrothermal performance and thermodynamical performance at varying Reynolds numbers (Re). The novel results of multi-objective optimum design are a unique aspect of this work by combining the results of RSM with CFD, where low porosity (ε = 0.1), low applied heat flux (Q = 100 × 103 W/m2) and low location jet ratio (LRVin = 0.26) were achieved the aim of the optimum hydrothermal performance (NumP/NumS = 25-30 times and Tb Reduction% = 83.5%-89.5%) and the thermodynamical performance (EG Reduction% = 93%-96% and CoPCarnot = 2.3-6.5 times). Thus, a valuable procedure for the optimal design of the hydrothermal and thermodynamical performance for porous multi-jet impingement cooling is proposed. [ABSTRACT FROM AUTHOR]

Nowadays, 3D printing is becoming an increasingly common option for the manufacturing of sensors, primarily due to its capacity to produce intricate geometric shapes. However, a significant challenge persists in integrating multiple materials during printing, for various reasons. In this study, we propose a straightforward approach that combines 3D printing with metal coating to create an array of resistive force sensors from a single material. The core concept involves printing a sensing element using a conductive material and subsequently separating it into distinct parts using metal-coated lines connected to the electrical ground. This post-printing separation process involves manual intervention utilizing a stencil and metallic spray. The primary obstacle lies in establishing a sufficient contact surface between the sprayed metal and the structure, to ensure effective isolation among different zones. To address this challenge, we suggest employing a lattice structure to augment the contact surface area. Through experimental validation, we demonstrate the feasibility of fabricating two sensing elements from a single-material 3D-printed structure, with a maximum electrical isolation ratio between the sensors of above 30. These findings hold promise for the development of a new generation of low-tech 3D-printed force/displacement sensor arrays. [ABSTRACT FROM AUTHOR]