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Modern medicine has taken energy loss during cilia beating in the human stomach, which under some circumstances causes blood flow to become acidic, very seriously. In current report covering a whole advancement and results for the impact of Rabinowitsch model with cilia-driven flow analysis with the help of ciliary beating in a cylindrical tube. The fluid is incompressible, and layers of fluid do not mix. The fluid flow with heat and mass transfer is firstly modeled in wave and then transformed into fixed frame. Exact solutions for stresses, temperature velocity, and concentration profiles whereas numerical pressure rise is obtained subject to relevant boundary conditions. The behavior of incipient parameters is shown graphically (plotted in MATHEMATICA 13.0) in the results section. The key findings obtained from graphical results show that maximum magnitude for velocity and temperature is achieved in middle layer of fluid whereas in the outer layer concentration profile is maximum. The current study may help researchers to develop new treatments for diseases such as cystic fibrosis, in which impaired ciliary function leads to mucus accumulation in the lungs. The attained exact and numerical outcomes are novel and offered here for first time in literature. [ABSTRACT FROM AUTHOR]

ABSTRACT Serrated spiral‐finned tubes have been extensively applied in heat exchangers, but the main research on them is about sensible heat transfer processes and only a few studies focus on condensation behavior. In this research, a model of mass and heat transfer about condensation of water vapor on the outside tube surfaces is developed by Fluent combined with a user‐defined function. The effects of different finned tube geometrical parameters are investigated. The model's reliability is verified by experiments on smooth tubes. The model is applied to finned tubes with different structures. A simple evaluation index qln·j/f$$ \left({q}_{\mathrm{ln}}\cdotp j\right)/f $$ about the dimensionless condensation rate qln$$ {q}_{\mathrm{ln}} $$, the dimensionless heat transfer factor j, and the resistance factor f is used to assess the comprehensive heat transfer performance of these finned tubes. The simulation results reflect that the increase of the base tube's outer diameter could enhance the comprehensive heat transfer performance, whereas the increase of the height and width of the open tooth will weaken the comprehensive condensation heat transfer performance to a different degree. Finally, the correlation equations of Nu, Eu, and dimensionless condensation rate qln$$ {q}_{\mathrm{ln}} $$ with wet air flow rate, water vapor content, base tube's outer diameter, and height and width of the open tooth are fitted, the deviations of Nu are not more than 5%, and the relative deviations of qln$$ {q}_{\mathrm{ln}} $$ and Eu could satisfy that 93% of the data is within 30%. Then, the finned tube geometry with optimal integrated condensation heat transfer performance (do$$ {d}_{\mathrm{o}} $$ = 23 mm, h2$$ {h}_2 $$ = 6 mm, w = 2.97 mm) is obtained. [ABSTRACT FROM AUTHOR]

The applications of swirling interfaces with heat and mass transfer are diverse and impactful, spanning industries from energy and manufacturing to healthcare and environmental protection. This study focuses on the stability of such interfaces where a viscous fluid interacts with a Rivlin–Ericksen (RE) viscoelastic fluid, undergoing heat and mass transfer. In this paper, the fluids are enclosed between two cylinders, one stationary and the other rotating. Mathematical equations are solved using potential flow theory. The interface stability is assessed using a normal mode procedure, leading to a second-order polynomial equation. The study finds that swirling flow reduces perturbation amplification, especially when heat and mass transfer occur simultaneously. However, the viscoelastic nature of the Rivlin–Ericksen fluid destabilizes the interface. Overall, this research provides valuable insights into complex fluid behavior with applications across industries. [ABSTRACT FROM AUTHOR]

The article addresses the issue of numerical modeling of the process of forming the temperature regime of earth dams, along with their foundations, built and operated in permafrost conditions. A large number of such structures have been constructed in the permafrost regions of the Earth to meet the needs of industry and population. The paper outlines the key principles of designing and constructing such structures. These principles were developed based on years of experience in hydrotechnical construction. Failure to follow these principles leads to structural failures, as confirmed by the presented statistics on accidents. It is essential to ensure the appropriate thermal condition of the structure and its foundation, either frozen or thawed. An unplanned transition of soils from one state to another may lead to an emergency situation. Temperature changes can cause phase transitions of water from liquid to solid (ice), which also affects the formation of the structure's regime. Numerical methods of calculation allow for the most comprehensive consideration of the influencing factors and processes. The article presents the results of numerical modeling of the filtration-temperature regime of an earth dam with a foundation in permafrost conditions, using two computational programs. The first is based on a locally variational approach (Termic, authored by the researchers), while the second uses a classical linear equation system solution (PLAXIS 2D 2022 software). A comparison of the results obtained from both programs showed good qualitative and quantitative consistency. Under the influence of seepage flow, the zone of frozen ground degradation is spreading in the lower part of the earth dam and its foundation. By September of the 27th year of operation, the thawed ground zone reaches approximately the middle of the structure at the base. The temperature values along the screen axis at the base of the structure are +1.2 °C (according to the Termic program—ver. 1.1) and +1.06 °C (according to PLAXIS 2D PC). Recommendations and future research directions on this topic are also formulated. [ABSTRACT FROM AUTHOR]

A microreactor with airfoil fins (AFMR) driven by solar heat transfer oil (HTO) was proposed based on the concept of printed circuit heat exchanger for enhance the hydrogen production efficiency of the indirectly heated solar reactor. The heating and reacting channels of the reactor were arranged in the reverse direction, and airfoil fins arrays were adopted to enhance heat and mass transfer. The performance of the AFMR was numerically investigated by developing a three-dimensional model, and compared with that in the traditional microreactor (TMR). The effects of geometric parameters and operating parameters of the AFMR on reforming performance were analyzed. The results indicate that the fin structure in the AFMR can increase the catalyst loading, mixes the gas flow to improve the chemical reaction rates. The increase in fin height and width has an impact on species transport, thereby influencing hydrogen production performance in the AFMR. Compared with the TMR, the AFMR leads to the significant enhancement in the methanol conversion at the cost of a slight increase in pressure drop. Under the conditions of T H,in = 523 K and u R,in = 0.2 m s−1, the AFMR achieves methanol conversion of 94.38% and pressure drop of 9.62 Pa, which are 16.61% and 1.04 Pa higher than those of the TMR. Moreover, the HTO inlet temperature has a more significant impact on the methanol conversion and carbon monoxide selectivity of the AFMR compared to the reactant inlet flow rate. • A microreactor based on concept of PCHE for efficient hydrogen production proposed. • Effects of geometric and operating parameters of airfoil-fin microreactor analyzed. • Airfoil fin can strengthen catalyst loading capacity, heat and mass transfer. • Methanol conversion and pressure drop of 94.38% and 9.62Pa achieved. [ABSTRACT FROM AUTHOR]

Introduction: A comprehensive assessment of a photovoltaic (PV) integrated hybrid solar dryer (HSD) for drying paddy was undertaken in the present investigation. Performance evaluation of the system along with finite element model of HSD at no-load and load conditions were successfully developed. Methods: A three-dimensional PV aided hybrid solar dryer assembly model was created in indoor simulations using COMSOL Multiphysics version 5.3 a. Solidworks 16 was used to build the dryer's collector, drying chamber, chimney, and thin food grain layer.Mesh refinement tests verified the mesh size independence of the panel temperature forecast finite element model. Results and Discussion: Collector efficiency ranged from 49.24% to 81.19% and peaked at 750 W/m2 thermal intensity. System evaporation ranged from 0.25 to 0.39 kg/h. We also compared HSD, tray dryer (TD), and mixed-mode solar dryer (MMSD) system efficiency, specific energy consumption (SEC), and specific moisture extraction rate (SMER). HSD SEC values were 72% and 46% lower than TD and MMSD. HSD, MMSD, and TD had SMER values of 0.27, 0.15, and 0.08 kg/kWh. HSD dried paddy samples 36.36% and 84.61% faster than TD and MMSD. Hybrid solar dryers saved 33% and 50% more time than mixed mode and tray dryers, respectively. Simulations of the collector and chamber air distribution profiles showed a dead zone where air velocity drops below 0.5 m/s. I must note that the model accurately predicted the dryer's temperature, wetness, and air dispersion pattern at load and no-load. PV-assisted HSD is suitable for sustainable food grain drying, according to this study. [ABSTRACT FROM AUTHOR]

In this study, the optimization of heat transfer in a metal hydride hydrogen tank to maximize hydrogen storage was investigated. A finite element model of a quarter tank was developed in COMSOL Multiphysics with parameterized geometry. The main objectives were to maximize stored hydrogen mass and minimize tank filling time while maintaining temperature uniformity within the tank. A design of experiments (DOE) approach was used with key geometrical parameters. Compared to the base case, the hydrogen stored mass increased from 0.26 to 0.46 kg, and the tank filling time reduced from over 1100 to 450 s. The optimal design (Design point 15) resulted in an absorbed hydrogen mass of 0.4624 kg, with a charging time of 450 s, showing the most balanced performance in terms of maximizing storage while minimizing filling time and better heat dissipation. This demonstrates the potential of optimizing heat transfer to significantly improve metal hydride hydrogen storage performance. The model can be further improved by exploring different cooling designs and materials. [ABSTRACT FROM AUTHOR]

Fractional calculus plays a pivotal role in modern scientific and engineering disciplines, providing more accurate solutions for complex fluid dynamics phenomena due to its non-locality and inherent memory characteristics. In this study, Caputo's time fractional derivative operator approach is employed for heat and mass transfer modeling in unsteady Maxwell fluid within a cylinder. Governing equations within a cylinder involve a system of coupled, nonlinear fractional partial differential equations (PDEs). A machine learning technique based on the Levenberg–Marquardt scheme with a backpropagation neural network (LMS-BPNN) is employed to evaluate the predicted solution of governing flow equations up to the required level of accuracy. The numerical data sheet is obtained using series solution approach Homotopy perturbation methods. The data sheet is divided into three portions i.e., 80 % is used for training, 10 % for validation, and 10 % for testing. The mean-squared error (MSE), error histograms, correlation coefficient (R), and function fitting are computed to examine the effectiveness and consistency of the proposed machine learning technique i.e., LMS-BPNN. Moreover, additional error metrics, such as R-squared, residual plots, and confidence intervals, are incorporated to provide a more comprehensive evaluation of model accuracy. The comparison of predicted solutions with LMS-BPNN and an approximate series solution are compared and the goodness of fit is found. The momentum boundary layer became higher and higher as there was an enhancement in the value of Caputo, fractional order α = 0.5 to α = 0.9. Higher thermal boundary layer (TBL) profiles were observed with the rising value of the heat source. [ABSTRACT FROM AUTHOR]

This study aims to elucidate the dynamics of moisture and temperature alterations in Camellia oleifera seeds during hot air drying and subsequent bursting. A systematic investigation was carried out to optimize the parameters for superior drying. The exceptional energy efficiency was characterized by minimizing energy consumption. The physical attributes of Camellia oleifera seeds were measured to determine their inherent properties, including thermal conductivity and density. The thermodynamic behavior of Camellia oleifera seeds was explored during drying at distinct temperature intervals of 52, 62, and 72 °C. According to Fick's Second Law, the effective moisture diffusion was then obtained corresponding to each temperature regime. An Arrhenius equation model was constructed in the empirically derived data on effective moisture diffusivity using reverse engineering. There was a significant correlation between effective moisture diffusivity, drying temperature, and activation energy. At the same time, a mathematical framework was designed to combine the heat and mass transfer, in order to simulate the drying of Camellia oleifera seeds. The predictions exhibited striking consistency with the experiments, with a maximum error of 8.5%, indicating the remarkable precision and reliability of the model. The results show that the hot-air drying dynamics of Camellia oleifera seeds were fundamentally dominated by internal mass transfer. The higher moisture gradients were observed than those of temperature ones. The fluctuation of drying rates shared a uniform pattern over the varying drying temperatures. The effective moisture diffusivity of Camellia oleifera seeds increased significantly over the temperature spectrum from 52 °C to 72 °C, ranging from 3.299 4×10-10−5.582 6×10-10 m² /s. The energetic transformations were computed as the activation energy of 25.025 kJ/mol during drying. Therefore, the variable temperature drying was performed better for Camellia oleifera seeds. There was the governing impact of three parameters— the initial wind temperature, the moisture conversion threshold, and the concluding wind temperature on specific energy consumption and drying velocity. Response surface optimization was applied to determine the optimal combination of drying parameters: an initial wind temperature of 63.7 °C, a moisture conversion point of 38.5%, and a terminal wind temperature of 74.8 °C. The better performance was achieved under these optimal conditions. Specific energy consumption was reduced to 5.040 kJ/g and a drying rate peaking at 0.048 g/(g·h). Compared with the model, relative errors for specific energy consumption and drying rate were 7.4% and 12.1%, respectively, indicating the pragmatic applicability and accuracy of the optimized parameters. In summary, a robust theoretical groundwork was offered to refine the practical drying parameters for Camellia oleifera fruit hot air drying and bursting, paving the way for industrial implementation and dissemination of Camellia oleifera fruit drying. Thus, considerable academic significance was provided for the promising practical application. [ABSTRACT FROM AUTHOR]

Water production by underground condensation is a low-capacity water-gathering technology for hot, humid climates. Hot, humid air is routed to subterranean pipes where it is progressively cooled and the vapor within the pipes appears as water droplets on the pipe surface. The goal of this paper is to quantify the amount of water extracted in the condensation system of humid and hot air. The water produced from humid air in buried pipes in the ground at a 0.5 m depth with different lengths is evaluated using MATLAB software, and optimal pipe length is established. Numerical findings show that water production is about 1 kilogram per day. It has been investigated how air temperature, pipe material, soil temperature, air humidity, and input speed influence underground condensation water production. It has been determined that 20 meters is the optimal length of the pipe. According to studies, Sandstone soil can produce 86%more water than other types of soil. It is also revealed that copper pipes could improve efficiency by 31%. The impact of effective factors on the efficiency of the condensation system, such as intake air temperature and humidity, inlet air velocity, and soil temperature, has also been assessed. [ABSTRACT FROM AUTHOR]

• The countercurrent hollow fiber membrane module is proposed for cold water generation. • A 3-D numerical model is developed accounting for irregular fiber filling. • Channeling effect and flow dead zones degrade the heat and moisture transport. • Irregular fiber filling increases the air side heat transfer resistance by >158 %. • Irregular fiber filling offers the potential to improve energy efficiency under certain conditions. The countercurrent hollow fiber membrane-based evaporative water cooler (MEWC) offers an eco-friendly and compact solution for cold water generation. This study introduces a random sequential addition algorithm to model the real-world irregular fiber filling within the MEWC. Inspired by the honeycomb structure, the developed 3-D numerical model adopts a calculation unit featuring a hexagonal prism comprising multiple fibers. Validation against experimental data reveals an average relative error of 2.81 % concerning outlet water temperature. The effects of fiber filling patterns (regular layout and random layout) on the velocity and temperature fields of the MEWC are investigated. Comparisons of outlet water temperature, cooling efficiency, consumptive electric power ratio, and heat and mass transfer resistance composition between these layouts under various operating conditions are conducted. The results indicate that the random layout fosters severe channeling effect and large flow dead zones, impairing air side heat and moisture transfer. The random layout exhibits over 15.9 % reduction in cooling efficiency and 36.3 % decrease in consumptive electric power ratio compared to the regular layout. Irregular fiber filling leads to a notable 158.6 % increase in air side heat transfer resistance and a 35.9 % rise in mass transfer resistance. Although irregular filling compromises the cooling performance, it demonstrates potential for energy savings under certain conditions. Design schemes should be carefully tailored to meet specific application requirements by considering these trade-offs. [ABSTRACT FROM AUTHOR]

Understanding the thermal conditions inside a burning cigarette is a top priority for controlling chemical emissions and cigarette design. Since experimental methods are difficult to observe in depth, this paper starts from the perspective of numerical simulation and models the structure of the tobacco distribution of the cigarette, integrating the end surface ignition model, puffing model, chemical reaction model, heat and mass transfer and diffusion model have established a three-dimensional comprehensive model that can represent the changes in combustion cone morphology during cigarette combustion. The model covers chemical reaction and mass transfer as well as generation, flow and reaction mechanism. The simulation results show that the model can better predict the temperature distribution, component distribution and combustion cone morphology changes during cigarette smoking and combustion. It provides an effective means for in-depth research on cigarette combustion. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyze how thermal stratification affects fluid movement past an impulsively initiated infinite upright plate when first‐order chemical reactions are present. Laplace's transform method is applied to achieve a closed‐form solution for the nondimensional governing equations when Pr=1. The formula L{n(t)}=∫0∞e−stn(t)dt=n¯(s), where t is the time and s is a parameter, can be used to obtain the Laplace transform of an exponentially ordered piece‐wise continuous function n(t). The unstable flow past an infinite vertical plate, starting abruptly in the presence of heat stratification and chemical reactions, has never been studied before. The research focuses on the combined impact of thermal stratification and chemical processes on the flow of an incompressible viscous fluid over an indefinitely tall plate. In this study, the significant findings that resulted from heat stratification are compared to the condition in which heat stratification is absent. The impacts of a number of parameters, such as S,K,Gr, and Gc, are investigated and visually displayed with respect to the following variables: concentration, velocity, shear stress, rate of heat transfer, temperature, and rate of mass transfer. It is demonstrated that applying stratification increases the frequency of oscillation in shear stress and heat transfer rate. The results obtained can be useful in the design of heat exchangers and other engineering applications. [ABSTRACT FROM AUTHOR]

Thermal effects of adsorption and desorption, leading to temperature fluctuations and losses of adsorption storage systems capacity in the processes of gas charging and discharging, are the main obstacle to the wide practical application of adsorbed natural gas (ANG) technology. This work presents a numerical simulation of heat and mass transfer processes under various cyclic operation modes of a full-scale adsorption storage tank with various thermal control systems. The high-density monolithic adsorbent KS-HAM, obtained on the basis of industrial activated carbon KS-HA, was used as the adsorption material. The phase composition, surface morphology, and porous structure of the sorbents were studied. The adsorption of methane on the KS-HA adsorbent was measured. It is shown that increasing the duration of charging leads to obtaining additional capacity of the ANG system; however, the final efficiency and benefit at the end of the charging–discharging cycle are determined by the efficiency of the thermal control system and the gas-discharging mode. It has been shown that the presence of a finned thermal control system allows for charging the adsorption storage tank 3–8 times faster and provides an 8–24% greater amount of gas discharged at the discharging stage compared to the ANG system without fins. [ABSTRACT FROM AUTHOR]

This article investigated deep-frying characteristics of malpoa for varied frying time (2–10 min) and temperature (170–190 °C). The evaluation encompassed a comprehensive analysis of textural and color kinetics and heat and mass transfer modeling during deep fat frying of malpoa balls. Such investigations confirmed an enhancement in fat content from 10.2 to 41.65%. On the other hand, textural properties such as hardness, cohesiveness, and springiness varied from 3.14 to 22.59 N/mm, 0.22 to 0.76, and 15.5 to 49.56, respectively. Similarly, color parameters such as b*/a* and ΔE varied from 3.31 to 1.55 and 55.36 to 75.48. For the textural and color kinetics, the activation energies ranged between 58.65 and 85.82 kJ/mol and 31.34 and 64.34 kJ/mol. Similarly, for a variation in frying time from 2 to 10 min, responses (hardness, cohesiveness, springiness, and overall color) varied across the following ranges: 3.15–13.57 N, 0.22–0.66, 15.5–35.5, and 55.63–63.50 and 5.60–20.60 N, 0.30–0.77, 22.35–49.56, and 62.26–75.65 for temperatures of 170 and 190 degrees, respectively. On the other hand, heat and mass transfer analysis indicated a Biot number and heat transfer coefficient within the range of 0.31–0.65 and 25.58–34.64 for 170–190 °C. Thus, this investigation provides a deeper insight of the deep fat frying characteristics of malpoa. This provides a guideline for the food processing sector for such products. [ABSTRACT FROM AUTHOR]

The document discusses the field of thermal engineering, which involves the transport and utilization of thermal energy in the design, manufacture, and use of products. It covers topics such as heat transfer mechanisms, combustion engineering, heat engines, micro- and nano-scale heat transfer, and thermal system design. The text emphasizes the importance of reducing carbon emissions, transitioning to sustainable energy systems, and addressing global climate change through technological advancements in thermal engineering. The author, Xianguo Li, provides insights into the historical development of thermal engineering and highlights the need for interdisciplinary collaboration to tackle energy challenges effectively. [Extracted from the article]

In the paper, a mathematical model was constructed that describes the specifications of the wind flow and the dispersion of pollutants, taking into account the variable temperature on the roadway surface, which varies depending on the time for some quarter of the city of Almaty. The impact of the traffic tidal flow was studied based on the data of measuring passing vehicles as a source of pollution by the CFD and on the spatial distribution of pollutants for various types of pollution. A test problem was performed to validate the numerical algorithm and the mathematical model. From the obtained numerical solutions, it was determined that the existing barriers along the road have a positive effect on pedestrian zones regardless of the type of pollution. It was also found that, taking into account the variable temperature on the carriageway, the presence of barriers with a height of 4 m shows favorable behavior on the adjacent areas, in which the average concentration value drops by 6.4 times for the pedestrian zone, which is located on the left side and 2.9 times for the pedestrian zone, which is on the right side compared to the option without a barrier. [ABSTRACT FROM AUTHOR]

Throughout drying, grains undergo exposure to heat sources and airflow, facilitating the expeditious evaporation of water present on their surfaces. As moisture migrates from inside the grains to the its periphery, it is conveyed through the transport channels within the grains, and finally evaporating to the external surroundings. The interaction between heat and water through the bulk of grains is explicated with empirical equations and principles of heat and mass transfer. This review work delves into studies on mathematical modeling aimed at elucidating the grain drying and storage, thereby delineating a specific mathematical model. The Midilli, Wang, and Singh model, grounded in the equations of Navier-Stokes, Maxwell, and Fourier, emerges as a prevalent choice, yielding satisfactory outcomes in simulating drying parameters when compared to literature data. This study seeks, therefore, to contribute to the comprehension and refinement of numerical models used to grain drying and storage. [ABSTRACT FROM AUTHOR]

Dryers are designed once but then operate for many years, and it is important to have systematic methods to solve problems when they arise. Kemp and Gardiner proposed a systematic methodology in 2001, based on categorization of problems into five main types and a divergent-convergent algorithm to identify both root causes and potential solutions. This approach to troubleshooting has proved successful for dryers in a range of industries. This article reviews the experience gained, some resulting improvements, and overlap and synergy with other investigation methods such as Lean Six Sigma techniques. An extensive range of case studies is given, illustrating the successful application of the methodology to many different situations and dryer types. The broad approach has remained the same but various points of detail have been added. Appropriate theoretical models can give useful insights, often using quite simple methods such as heat and mass balances and drying times estimated with first-order kinetics. The insights can solve other drying-related problems such as caking in storage. The methods can also be used for process improvement, debottlenecking, and enhanced product quality. [ABSTRACT FROM AUTHOR]

This study investigates the fluid flow, heat, and mass transfer phenomena within a vertical channel containing two immiscible fluids, with a particular focus on slip effects. These effects include no slip, velocity slip, thermal slip, and multiple slips, each analyzed with appropriate boundary conditions. The study thoroughly examines key characteristics, such as variations in thermal conductivity and viscosity. Using a sixth‐order Runge–Kutta numerical method implemented using Mathematica, the study achieves precise solutions for complex scenarios. The detailed results show how the various slip mechanisms and relevant parameters interact with each other in complex ways. These findings are useful for both theoretical understanding and application in real‐life engineering situations. This study also gives important information about how fluid flow, heat transfer, and mass transfer change under different slip effects. It looks at these effects and shows how they change visually. It also carefully calculates and analyzes engineering parameters like the Nusselt number, shear stress, and Sherwood number using bar charts, showing how they affect and behave. The study resulted in velocity slip having a minimal impact on temperature, whereas thermal slip resulted in higher temperatures. Both velocity and thermal slip conditions simultaneously result in the lowest temperatures. [ABSTRACT FROM AUTHOR]

Liquid desiccant deep dehumidification (LDDD) is an excellent energy-saving technology for low-humidity industries. Ionic liquids (ILs) are favored as optimal working fluids for LDDD, owing to their low vapor pressure, non-crystallization, and non-corrosion. The combined application of IL desiccant with the bubble column has been proven to effectively improve deep dehumidification. The present work focuses specifically on the insights into air-liquid transfer processes in bubble column dehumidifier using ionic liquid desiccant. The effect of operating parameters on volumetric transfer coefficient is examined based on the experimental platform. Meanwhile, the bubble swarms meso-scale flow structure is predicted using computational fluid dynamics coupled with a population balance model (CFD-PBM). Besides, the structure-activity relationship between meso-scale flow structure and transfer performance is investigated. The results indicated a notable phenomenon of bubble aggregation/breakage in the moist air-IL desiccant bubbly deep dehumidification (MA-ILD BDD) system, with a specific interfacial area is basically less than 40 m−1. Meanwhile, a decrease in solution temperature, correlated with a significant increase in viscosity, leads to larger turbulent eddies and a slower breakage rate. Notably, a high transfer potential difference enhances heat and mass transfer coefficients at lower solution temperatures, with the mass transfer coefficient at 4°C being approximately three times that at 10°C. As the superficial velocity changes, the specific interfacial area and heat and mass transfer coefficients have a positive synergistic effect on volumetric transfer coefficient. However, this synergistic effect is reversed with variations in solution temperature. This study aims to clarify the air-liquid transfer mechanism in bubble column dehumidifier using IL desiccant. [ABSTRACT FROM AUTHOR]

The Runge-Kutta method combined with the shooting technique is used to solve the numerical results of the theoretical model for the electrically conducting micropolar fluid through two parallel plates in the presence of a heat source or sink and first-order chemical reactions in the flow heat and mass transfer equations. This work encourages us to use the Homotopy analysis approach to develop semi-analytical solutions for dimensionless velocity, dimensionless microrotation, dimensionless temperature, and dimensionless concentration. The answers are used to produce the analytical approximations of the physical characteristics, such as the skin friction factor, Nusselt number, and Sherwood number. Additionally, tabular values for the physical parameters, such as the skin friction factor, Nusselt number, and Sherwood number, are provided. Graphs are also used to illustrate how characterizing parameters behave. We found a high correlation between the semi-analytical and numerical findings of this study when we compared our semi-analytical works with the earlier studies. Compared to the prior method, this approach to the model is simpler, and it may be readily extended to find semi-analytical solutions to other MHD and EMHD fluid flow issues in the physical sciences and engineering.

The aim of this study is to examine the entropy generation (EG) associated with the transfer of mass and heat in a concentration-dependent fluid with thermal radiation and activation energy, specifically in the context of an unsteady Riga Plate with gyrotactic microorganism. It is important to solve the ordinary differential equations generated from the controlling partial differential equations using Lie symmetry scaling to verify their quality and reliability. The system’s anticipated physical behavior is compared to Mathematica’s Runge–Kutta–Fehlberg numerical solution. Source parameters are essential for validation since they offer accurate results. Methodically change these values as a percentage to determine how they affect the unsteady fluid’s density, mass, and heat transfer over the Riga plate. Velocity, temperature, nanoparticle concentration and microorganism concentration profiles decrease with varying values of the unsteadiness parameter. EG increases with increasing values of concentration difference, thermal radiation, and Reynold number parameters. The Nusselt number experiences a 26.11% rise as a result of radiation when the unsteadiness parameter is A=−0.25A=-0.25, in comparison with the scenario without radiation. Mass transfer upsurges with increasing values of the Brownian motion parameter and reduces with increasing values of thermophoresis parameter. To verify our conclusions, we compare calculated data, specifically the skin friction factor, to theoretical predictions. Tabular and graphical data can show how physical limits affect flow characteristics.

The goal of this work is to further improve our knowledge of the nonlinear radiative second-grade nano fluid flow boundary layer phenomena which is associated with an Arrhenius activation energy, a sinusoidal magnetic field, and a stretched peripheral with a heat source. The unsteady governing equations are transformed into a proper dimensionless arrangement, and then the explicit finite difference (EFD) method is applied to numerically calculate the equations. However, precise stability and convergence criteria have been developed to make the solution convergent. Along with the typical profile of other flow fields, the oscillatory forms of the velocity are shown. Tabular research has even demonstrated a relationship between the Nusselt number and other parameters, and graphical depiction has been used for regression and data prediction. The novel conclusions drawn from this research indicate that, in comparison to linear patterns, nonlinear radiative heat flux significantly raises (30.35 %) flow profiles with second-grade characteristics. Moreover, the heat transfer rates of second-grade Nano fluids are seen to be significantly influenced (35.14 %) by the sinusoidal magnetic component. When considering nonlinear thermal radiation, activation energy principles cause a major change (34.19 % more) in mass transmission, as high-temperature processes become an essential part of chemical reactions.

This study investigates the impact of porosity distribution on the hydrogen storage performance of metal hydride (MH) reactors through numerical simulations. Firstly, the effects of different porosities on heat and mass transfer characteristics during hydrogen adsorption and desorption processes were analyzed. The results indicate that with increasing porosity, the hydrogen storage and release rates improved, but the hydrogen storage density decreased. To enhance reactor performance while maintaining hydrogen storage density, the bed porosity distribution was optimized. The optimization results showed that the hydrogen storage and release times of the MH reactor were reduced by 57.15% and 29.70%, respectively, at the same hydrogen storage density. Moreover, the optimized structure exhibited excellent hydrogen storage and release performance under different operating conditions, demonstrating its potential advantages in practical applications. • MH bed porosity significantly affects heat and mass transfer performance. • Bed porosity distribution is optimized by Monte Carlo algorithm. • Hydrogen storage and release times are reduced by 57.15% and 29.7%. • Optimized structure shows superior performance under various conditions. [ABSTRACT FROM AUTHOR]

This study investigates the dehumidification performance and the gas-liquid flow of a falling film liquid desiccant dehumidifier with different plate configurations: vertical smooth, vertical rough, and inclined rough. Utilizing ANSYS Workbench 2020 R1, the Re-Normalization Group (RNG) k-e turbulence model has been utilized to simulate the gas-liquid flow, and the volume of fluid model is employed to track the interface patterns between the gas and liquid phases. This model takes into account the effects of the two-dimensional turbulent flow which is performed for various plate configurations under situations of unstable gas-liquid flow. The 30% LiCl solution is used as an absorbent and hence, the performance has been evaluated using a constant mass transfer rate of 50 mol/s. Furthermore, the LiCl solution's mass concentration is taken into account as 30%, 33%, 36%, 40%, and 44%, respectively, for the justification of the influence of various concentrations of LiCl solution. The study analyzes the fields of mass fractions and the mechanisms that lead to the enhancement of dehumidification. The research examines the influence of inlet desiccant concentration and air velocity on mass transfer properties, revealing that an inclined ribbed plate significantly enhances dehumidification up to 10.8% compared to the smooth plate particularly at 1.5 m/s inlet air velocity by generating liquid film waves and increasing contact time between the liquid desiccant and moist of air. Lower inlet air velocities and higher inlet desiccant concentrations resulted in a decreased outlet mass percentage of water vapor. The optimal LiCl concentrations for water vapor absorption are 30-40%, with efficiency stable above 36%, though benefits may plateau beyond a certain level. The study concludes that the inclined rough plate enhances mass transfer performance at various inlet air velocities and desiccant concentrations by increasing the contact time between the liquid desiccant and moist air, increasing the rate of water vapor absorption. These findings provide valuable insights for researchers and engineers aiming to optimize liquid desiccant dehumidification systems for various applications, especially in the hybrid liquid desiccant-vapor compression systems. [ABSTRACT FROM AUTHOR]

Smoking and hypertension are significant risk factors for atherosclerotic carotid artery disease, but also for intracranial aneurysms. The medical results suggest incidental intracranial aneurysms in patients with internal carotid artery (ICA) stenosis arteries. Which led to a study of the comparison between stenosis and aneurysm segments through the artery. A mathematical and numerical model for blood solidification and its rupture in a diseased artery is described in this paper. The interaction between the blood flow and a diseased arterial wall was formulated. The blood flow is formulated as a micropolar incompressible fluid with heat and mass transfer under the control of electro-osmotic and electromagnetic forces through an artery that contains stenosis and aneurysms. The approximation of mild stenosis is used to derive the governing flow equation, which is then solved using a method of finite difference. Particular attention is paid to the impact on axial velocity, flow rate, resistance impedance, and wall shear stress of geometrical parameters of the arterial wall and rheological blood parameters. In the instantaneous pattern of streamlines, the global behavior of blood is also investigated. Finally, the effect of all parameters on the blood flow through artery whose stenosis and aneurysm are investigated as a comparison of both segments. [ABSTRACT FROM AUTHOR]

The water and salt movement and crystallization deformation of saline soil in cold and arid regions is a complex hydrothermal–salt–mechanical coupling problem. Based on the law of mass conservation, the law of energy conservation, and the theory of permafrost mechanics, the hydrothermal–salt–mechanical coupling mathematical model of unsaturated sodium sulfate saline soil is established. The model takes into account the latent heat of phase transition, crystallization impedance, consumption of crystallization, ice crystal self-cleaning behavior, and temperature as mechanical parameters. Numerical simulations using COMSOL Multiphysics (version 5.5) software were carried out, and the outcomes were analyzed and compared with unidirectional freezing test data. The findings show that the coupled model accurately simulates heat–mass transfer, crystallization, and salt freeze–thaw deformation in unsaturated saline soil. In the unidirectional freezing process, the temperature, salt freezing deformation, and freezing depth within the saline soil showed a three-stage rule of change, and the migration of water and salt to the freezing front made the water and salt content in the freezing zone increase significantly and form a laminar distribution, and the peak of the water and salt content appeared at the freezing front. The migration of water and salt aids in forming ice and salt crystals that rapidly grow within the soil pores of the freezing zone, leading to salt freeze–thaw deformation. Furthermore, the models and results of this study offer crucial insights into the mechanisms of soil salinization, desertification, and salt freeze–thaw deformation in cold and arid regions. [ABSTRACT FROM AUTHOR]

The goal of this work is to further improve our knowledge of the nonlinear radiative second-grade nano fluid flow boundary layer phenomena which is associated with an Arrhenius activation energy, a sinusoidal magnetic field, and a stretched peripheral with a heat source. The unsteady governing equations are transformed into a proper dimensionless arrangement, and then the explicit finite difference (EFD) method is applied to numerically calculate the equations. However, precise stability and convergence criteria have been developed to make the solution convergent. Along with the typical profile of other flow fields, the oscillatory forms of the velocity are shown. Tabular research has even demonstrated a relationship between the Nusselt number and other parameters, and graphical depiction has been used for regression and data prediction. The novel conclusions drawn from this research indicate that, in comparison to linear patterns, nonlinear radiative heat flux significantly raises (30.35 %) flow profiles with second-grade characteristics. Moreover, the heat transfer rates of second-grade Nano fluids are seen to be significantly influenced (35.14 %) by the sinusoidal magnetic component. When considering nonlinear thermal radiation, activation energy principles cause a major change (34.19 % more) in mass transmission, as high-temperature processes become an essential part of chemical reactions. [ABSTRACT FROM AUTHOR]

Utilizing spent refractory material (SRM), generated after the overhaul of aluminum electrolytic cells, as a raw material for producing Al-Si alloys presents an efficient approach towards achieving full resource utilization of SRM. However, a bottleneck restricting this technology has become the dissolution of SRM. Based on the heat and mass transfer mechanism, the shrinkage core model of SRM particle dissolution was established. The effects of alumina concentration, silica concentration, electrolyte superheat, particle temperature, and turbulent kinetic energy dissipation rate on the mass dissolution rate and dissolution time of SRM particles were investigated. Calculation results and experimental data were compared to confirm the accuracy of the established model. The results show that by maintaining low alumina and silica concentrations, increasing the electrolyte superheat and particle preheating temperature, and increasing the electrolyte turbulent kinetic energy dissipation rate, SRM particles can dissolve faster. The dissolution of agglomerated particles is greatly influenced by the turbulent kinetic energy dissipation rate and superheat. The present research provides promising guidance for practical application in predicting particle dissolution time, controlling process parameters, and accelerating the dissolution of SRM particles. [ABSTRACT FROM AUTHOR]

The sustainable utilization of biomass, particularly troublesome waste biomass, has become one of the pathways to meet the urgent demand for providing energy safety and environmental protection. The variety of biomass hinders the design of energy devices and systems, which must be highly efficient and reliable. Along with the technological developments in this field, broad works have been carried out on the mathematical modeling of the processes to support design and optimization for decreasing the environmental impact of energy systems. This paper aims to provide an extensive review of the various approaches proposed in the field of the mathematical modeling of the thermochemical conversion of biomass. The general focus is on pyrolysis and gasification, which are considered among the most beneficial methods for waste biomass utilization. The thermal and flow issues accompanying fuel conversion, with the basic governing equations and closing relationships, are presented with regard to the micro- (single particle) and macro-scale (multi-particle) problems, including different approaches (Eulerian, Lagrangian, and mixed). The data-driven techniques utilizing artificial neural networks and machine learning, gaining increasing interest as complementary to the traditional models, are also presented. The impact of the complexity of the physicochemical processes and the upscaling problem on the variations in the modeling approaches are discussed. The advantages and limitations of the proposed models are indicated. Potential options for further development in this area are outlined. The study shows that efforts towards obtaining reliable predictions of process characteristics while preserving reasonable computational efficiency result in a variety of modeling methods. These contribute to advancing environmentally conscious energy solutions in line with the global sustainability goals. [ABSTRACT FROM AUTHOR]

Evaluation of impact of temperatures (40°C, 50°C, and 60°C) on dried soursop fruit by determining the changes in thermal and mass transfer (MT) as well as nutritional and color changes and prediction of drying behavior by statistical tools were executed first time in this study. Interestingly, soursop involved many medicinal uses; therefore, it could be a healthy food substitute for the growing food industry, by being incorporated into fruit shakes, bakery products, capsules, and many more formulations. In this work, prediction ability was analyzed by an artificial neural network (ANN). TANSIGMOID transfer function along with Levenberg-Marquardt's training algorithm proved a better prediction of moisture content (MC) and moisture ratio (MR). Thereafter, a comparative analysis of predicted ANN data with ten different mathematical models was done. Page model gave the best fit to the experimental data. The R2 value of the Page model (0.9697–0.999) revealed lower values than ANN (0.9999). As the temperature increased, the moisture diffusivity and MT coefficient increased as of 3.76 × 10−6 to 6.25 × 10−6 and 4.569 × 10−5 to 1.148 × 10−6, respectively. The activation energy (AE) was obtained to be 22.148 kJ/mol. At 60°C, maximum antioxidant activity in water extract by DPPH, FRAP, ABTS, and PA was found to be IC50 922 μg/ml, 34.086 mM TAE/g, 21.336 μg/g, and 15.46 mg/g, respectively. Total polyphenol content and flavonoid content were observed to be 11.662 mg GAE/g and 21.442 mg QE/g, respectively, along with the acceptable appearance of dried soursop fruit powder at 60°C. Hence, 60°C temperature was recommended for drying raw soursop fruit. [ABSTRACT FROM AUTHOR]

In order to analyze the heat and mass transfer characteristics of cut tobacco in a horizontal drum dryer, the discrete element method (DEM) was used to calculate the particle collision model and DEM-CFD coupled heat transfer model. With the increase of the rotating speed, the mixing degree gradually increases, and when the rotating speed is 16 rpm, the mixing degree is higher. When the heat flux of DEM-CFD coupling is 0.2-1 W, the particle temperature will gradually increase and tend to a fixed value. The residence time of the material has a great influence on the drying quality of the material particles. If the residence time is too short, the heat of the material will be uneven, and if the residence time of the material is too long, the damage of the material particles will increase, increased crushing rate. [ABSTRACT FROM AUTHOR]

The work is devoted to investigating the influence of the mechanical field on temperature and diffusion processes occurring under steady bending of slender beams. The model used here takes account of the finite velocity of propagation of thermal and diffusion disturbances. A mathematical formulation of the problem includes the system of equations of unsteady flexural vibrations of the beam with account of heat and mass transfer, that has been obtained from the general thermomechanodiffusion model for continuous media using the generalized principle of virtual displacements. With the example of a hingedly supported three-component beam fabricated from a zinc, copper, and aluminum alloy and exposed to unsteady bending moments, the authors have investigated the interaction of mechanical, temperature, and diffusion fields, and also have analyzed the influence of relaxation effects on the kinetics of heat and mass transfer. [ABSTRACT FROM AUTHOR]

The low drying rate is the main limitation of atmospheric freeze drying. The drying rate depends on the balance between heat and mass transfer. Among the process variables, air pressure changes have the opposite effects on heat and mass transfer simultaneously. The increase in pressure favors heat transfer but hinders mass transfer. Therefore, a conjugate model was proposed and validated to quantitatively investigate the heat and mass transport characteristics of lamellar products during freeze-drying in a tunnel under different pressures (1.325–101.325 kPa). To describe the effects of air pressure, the Navier-Stokes equations of the external fluid were coupled with the adsorption-sublimation model. Results show the regulation of transfer resistance values and drying rate with moisture content during the drying process, indicating that freeze-drying is the external heat transfer control at first, then the internal mass transfer control, and eventually, the heat transfer promotion can accelerate the process. The optimal constant pressure value was found to be 5.325 kPa, with the shortest drying time (17.3 h). It has been demonstrated that freeze drying employing a specific laddering-controlled strategy, offers the benefit of reducing drying time in comparison to the use of optimal constant pressure; however, the impact was not remarkable. [ABSTRACT FROM AUTHOR]

The precise design of heat exchangers in automobile air conditioning systems for more sustainable electric vehicles requires an enhanced assessment of CFD mechanistic models for the subcooled boiling flow of pure eco-friendly refrigerant. Computational Multiphase Flow Dynamics (CMFDs) relies on two-phase closure models to accurately depict the complex physical phenomena involved in flow boiling. This paper thoroughly examines two-phase CMFD flow boiling, incorporating sensitivity analyses of critical parameters such as boiling closures, momentum closures, and population balance models. Three datasets from the DEBORA experiment, involving vertical pipes with subcooled boiling flow of refrigerant at three different pressures and varying levels of inlet liquid subcooling, are used for comparison with CFD simulations. This study integrates nucleate site density and bubble departure diameter models to enhance wall boiling model accuracy. It aims to investigate various interfacial forces and examines the S-Gamma and Adaptive Multiple Size-Group (A-MuSiG) size distribution methods for their roles in bubble break up and coalescence. These proposed approaches demonstrate their efficacy, contributing to a deeper understanding of flow boiling phenomena and the development of more accurate models. This investigation offers valuable insights into selecting the most appropriate sub-closure models for both boiling closure and momentum closure in simulating boiling flows. [ABSTRACT FROM AUTHOR]

The objective of this paper is to provide the reliable calculation procedure for determining heat and mass flow rates for plate finned tube heat exchangers in dehumidification regimes that can be used easily in engineering practice. For this purpose, the experiments are conducted on two heat exchangers, and datasets for six more heat exchangers are used from literature. Comprehensive database is established with total of 637 sets of data, and it gathers 365 new measurement sets and 272 sets from open literature. The new calculation procedure predicts heat transfer rate and condensate flow rate where new methodology approach (based on the porous velocity, the ratio of characteristic surfaces and hydraulic diameter) is used. Predicted results show 5–10 % deviation for heat duty and up to 20 % for mass flow rate from experimental results, which is of importance to industrial practice. [ABSTRACT FROM AUTHOR]