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AbstractIn CNC milling, the feed rate scheduling is a frequently used method to increase machining quality and efficiency. Among the benefits of feed rate scheduling, this paper focuses on controlling the tool load and optimizing the machining time. Although the advantages of feed rate scheduling are undeniable, some areas remain still to be addressed. In order to control the tool load, geometric methods are often used, which are based on keeping a specific parameter, such as chip thickness or material removal rate (MRR) constant. However, a high level of tool load control can only be provided if cutting force models or experimental-based techniques are used. Besides traditional methods, this paper presents an artificial neural network (ANN)-based feed rate scheduling method to keep the tool load constant, using data gained by preliminary cutting experiments. A case study demonstrates that a significantly higher level of tool load control can be achieved with this method as compared to the geometric models. Besides controlling the tool load, the present feed rate scheduling method also addresses the consideration of acceleration limits which is of great importance for practical uses. The application of feed rate scheduling in trochoidal milling is also discussed in detail in this paper. This area has not received enough attention, as due to the limited fluctuation of cutter engagement, the tool load was considered as well-controlled. However, experiments have shown that in the case of trochoidal milling, the introduction of feed rate scheduling can still further increase the machining efficiency. Using the developed ANN-based feed rate scheduling method, significant progress could be made as compared to conventional technologies in controlling the cutting force and optimizing the machining time. In the present case study, a reduction of 50% in machining time was achievable by adjusting the feed rate without increasing the peak value of cutting force.

In recent years, trochoidal milling has become greatly widespread since it provides high productivity and long tool life, especially when cutting difficult-to-machine materials. Numerous studies have dealt with the analytical description and the experimental investigation of the evolution of cutting force, temperature, tool wear, chatter stability, etc. However, most of these analyses are focusing on the conventional circular and cycloid-shape trajectories. Only a few studies address the potential of improving the efficiency by modifying the tool path shape, leaving significant reserves untapped. If the mathematical formulation of the trajectory cannot be described easily, then a sophisticated optimisation algorithm is needed to determine the appropriate tool path shape. To overcome these difficulties at trochoidal milling of straight slots, the present work proposes a new tool path generation algorithm that can maximize the average material removal rate (MRR) while controlling the tool load. In this approach, the tool path is modelled by a B-spline curve whose control points are optimised using a differential evolution algorithm. The developed tool path generation strategy was compared through simulations and experiments with two widely used solutions viz the traditional cycloid-shaped tool path and a modern approach used in computer-aided manufacturing (CAM) systems. The results reveal that the developed method is able to control the tool load and the smoothness of the tool path, and most importantly, also exceeds the existing methods in terms of productivity.

Erosive wear caused by particulates slurry is one of the major concerns in the pipe bend which may results in the failure of the pipe flow system. In the present work, erosion wear rate through mitre pipe bend caused by silica sand particulates slurry has been investigated using ANSYS Fluent code. The solid spherical particulates of size 125 µm and 250 µm having density of 2650 Kg/m3, were tracked to compute the erosion wear rate using Discrete Phase Method (DPM) model. The particulates were tracked using Eulerian-Lagrange approach along with k-ɛ turbulent model for continuous fluid phase. The silica particulates were injected at solid concentration of 5% and 10% (by weight) from the pipe inlet surface for wide range of velocities viz. 1–8 ms−1. The erosion wear rate was computed through four computational erosion models viz. Generic, Oka, Finnie and Mclaury. Furthermore, the outcomes obtained through Generic models are verified through existing experimental data in the literture. Moreover, the results of DPM concentration, turbulence intensity and particle tracking were predicted to analyze the secondary flow behaviour through the bend cross section. Finally, the effect of particulate size, solid concentration and flow velocity were discussed on erosion wear rate through bend cross section. The findings show that the locality of maximum erosive wear is positioned at the extrados of the bend outlet cross section. Additionally, it is found that Mclaury model offers higher erosion rate as compared to the other models and provides benchmark for designing the slurry pipeline system.

In the present work, nanostructured functionalized silica is coated on an aluminum (Al) substrate by the spray pyrolysis method to create a stable and effective super-hydrophobic substrate for water harvesting via moist air. Substrate characterization reveals that (1) major diffraction peaks corresponding to crystoballite SiO2 (C-SiO2), quartz (Q-SiO2), Al2O3, and Al2SiO5 are to be found at SiO2/Al interface; (2) strong chemically bonded methyl functionalized silica is confirmed on the Al surface by Fourier-transform infrared spectroscopy (FT-IR) and x-ray photoelectron spectrometry (XPS) shows the presence of Al-O-Si bond at the interface; and (3) the equilibrium contact angle of the water droplet on the coated substrate is measured to be 156° ± 5° with a hysteresis of 10° ± 3°. The coating is found to be stable for more than 365 days in a humid atmosphere. Finally, moist air condensation experiments confirm substantial augmentation of condensate collected ranging from 188 ml/m2-h over an untreated aluminum substrate to 750 ml/m2-h over the coated substrate. Hence, it is concluded that nanostructured silica-coated Al substrate is highly effective for enhancing the condensation of water vapor from a moist air environment.

Alternative recent technologies are sought-after to resolve the hastily growing water scarcity globally. The innovative techniques contributing to the water production implementing the method of condensation provides feasible study specifying factors affecting. The factors investigated from extant literature are reviewed to perform weightage to the criteria and ranking to the recognized condensation phenomenon. The weightage of the criteria is characterized by the implementation of the ENTROPY approach and the ranking of factors is performed by the MOORA method. The purpose of this manuscript is to strengthen different factors of sustainable water harvesting using condensation methods for efficiency improvements. The harvesting application with modified factors to their required hierarchy certainly proposes an economic and scalable to emerging and existing potable water generating system. The precise configuration of condensation factors will introduce environment-friendly, effective, and sustainable water-extracting systems in various fields.

The key issue associated with the industries is the transportation and dumping of solids particulates in the form of slurry at the desired place using long length pipelines. In this perspective, numerical simulation of three-dimensional horizontal slurry pipeline of 0.0549 m diameter using Eulerian two-phase model with RNG k-ɛ turbulence closure is carried out. The glass - beads solid particulates having density ( = 2470 kg/m3) and slurry concentration varies as 10% to 50% (by volume) for velocity ranges of 3-5 ms-1. The computational modeling is done using available commercial software ANSYS Fluent for 125µm and 440 µm particulate size at different velocity and concentration range to know their effect on slurry flow characteristics. It is observed that for chosen particulate size pressure drop increases with increase in velocity at all solid concentration range. The pressure drop in slurry for 440 µm solid particulates is found higher as compared to the pressure drop of 125 µm solid particulates slurry. The percentage change in pressure drop is also reported in the paper due to particulate size effect at all velocity and solid concentration. The obtained results of predicted pressure drop are analytically compared with the available experimental results of literature and are in synchronism with that. A parametric study is carried out with the aim of visualizing and understanding the solid particulate size effect on slurry flow characteristics. Finally, the results of settling solid concentration contour, velocity contour, concentration profiles, velocity profiles and vector representation of concentration/velocity were also predicted for chosen particulates sized slurry.

The condensation transport coefficients are higher on the metallic surface because of the high thermal conductivity of metallic surfaces. However, the metallic surfaces have a higher affinity to water in the condensation process which leads to corrosion and results in damage to the condensing metallic surface. Low surface energy and low wettability surfaces promote efficient condensation in drop mode. Therefore, several surface modification techniques have been adopted for modifying the surface wettability of the metallic surfaces. Teflon coating on the metallic surface has been an economically viable and simple method for fabricating low surface energy coating on metallic surfaces. In this work, Cu coil is coated with PTFE film for fabricating hydrophobicity on Cu helical coil. Moist air condensation experiments are carried out on Teflon coated and bare Cu coil to investigate the effect of Teflon coating on the coil. In addition, the effect of moist ambient conditions on the Teflon coated coil is addressed to examine the aging of the Teflon coating on the Cu coil. The results show that the characteristics of hydrophobic Teflon coating deplete with increases in exposure time so the dropwise condensation transits into mixed condensation and ultimately in film mode as the coil is exposed to repeated condensation cycles. The results of the present study are useful to appropriately investigating in which all applications the Teflon coating can be implemented such that all its properties are retained in that time duration.

The unmanned aerial vehicles are getting popular day by day owing to its ability to hover, low cost of maintenance, ease of deployment as well as high mobility. A quadcopter has limited mobility and payload, but they are highly capable to fly in any direction and to stay stationary in the air. Therefore, the battery lifetime is an important aspect to study which help to travel for a long distance and to increase the flight time. In this direction, the present work focuses on the flight time, which is being analyzed experimentally through the integration of solar panels in the quadcopter for utilization of solar energy as a power source along with the conventional DC battery and by efficient weight reduction of the quadcopter. The proposed quadcopter has been designed in SolidWorks© software and analyzed in Ansys© software as well as it has been fabricated successfully to test for flight time.

Hybrid metal matrix composite is an integration of two or more reinforcements to produce better strength, stiffness, and high strength to weight ratio. However, low material removal and high electr...

The surface tension of blood plays an important role not only in the birth and decompression sickness but also in other functionality of the organism. It also provides capillary action during blood flow process. In this article, a simple and low-cost device is designed and fabricated for measuring the surface tension of blood by pendant drop method. In this device, a droplet of blood is formed in a closed chamber on tip of an 18-gauge blunt needle and it is photographed by a camera in very humid conditions (RH = 99%) to minimise the evaporation. A wetted wick is provided at the bottom of the chamber for maintaining constant relative humidity in chamber. Surface tension of blood is inferred using drop shape factor method and image analysis technique at various experimental conditions. This device is validated and calibrated with surface tension measurements of water and silicone oil. Its measurements are in good agreement against data reported in literature. Post-validation, surface tensions of blood samples with and without anticoagulant of healthy persons at various temperatures (range from 20 to 40 °C) was measured. It was found that the surface tension of normal blood samples strongly correlates with blood temperature. The surface tension of female blood was remarkably different from same of male blood. However, the effect of age (21-60 year) on the surface tension was negligible for all practical purposes. Increased percentage of anticoagulant in blood increases its surface tension. This research specifies a baseline for surface tension of normal blood samples at various conditions which in turn provides new insights to pathologists in identifying various disease conditions.

Transportation of solids with water as a carrier in the form of slurry through long length pipelines is widely used by many industries and power plants. The transportation of slurry through vertical pipeline is a challenging task and require modification to overcome the pressure loss and power consumption requirements. In this perspective, numerical simulation of three-dimensional horizontal slurry pipeline (HSPL) and vertical slurry pipeline (VSPL) carrying glass beads solid particulates of spherical diameter 440 µm and density 2,470 kg/m3 is carried out. The 3D computational model for horizontal and vertical slurry pipeline is developed for a pipe of 0.0549 m diameter and analyzed in available commercial software ANSYS Fluent 16. The simulation is conducted by using Eulerian multiphase model with RNG k-ɛ turbulence closure at solid concentration range 10 – 20% (by volume) for mean flow velocities ranging from 1-4 ms-1. It is found that the pressure drop rises for both HSPL and VSPL with escalation in mean flow velocity and solid concentration. The predicted pressure drop in VSPL is found to follow the same pattern as with HSPL but higher in magnitude for all chosen velocity and solid concentration range. The obtained results of predicted pressure drop in HSPL are validated with the available experimental data in the literature. A parametric study is conducted with the aim of visualizing and understanding the slurry flow behavior in HSPL and VSPL. Finally, the results of solid concentration contour, velocity contour, solid concentration profiles, velocity profiles and pressure drop are predicted for both the slurry pipelines.

Moist air condensation is a complex process because it relies on numerous significant parameters such as physio-chemical properties of a surface, thermal-physical properties of the moist air, and environmental conditions. Thus, the manuscript intent to structure the model-framework of sustainable water harvesting based on moist air condensation on mesh-like surfaces to increase the availability of potable water. Hence, the significant key factors related to sustainable water harvesting via condensation are identified from extant literature, consultation from researchers, and practitioners and subsequently confirmed by fabricating the experimental setup. Further than, an attempt by applying Total Interpretive Structural Modelling (TISM) is attained to provide a model framework. Thereafter, the procedure for analysis using MICMAC is implemented which performed to categorize the identified factors into the distinct clusters’ dependent on their driving and dependence powers to justify their interrelationship with one another. The research reveals that surface coating, mesh geometry, and material of condensing surface are the most dominant factor in the required hierarchy which helps in improving the condensation rate. Thus, the prioritization of the factors with improvisation intends to fill the gap for scalable, economic, sustainable, and environment-friendly condensation in various fields. This research work can be benefited to the industry to the area of water harvesting and energy conservation. Also, the researchers can consider the most influential factors identified in this research while fabricating experimental setups.

A number of drag models have been suggested for the interaction of fluid particles in slurry flow over the previous centuries. It is necessary to examine the correctness and applicability of these models in the slurry transportation. Based on this concept, a comparative analysis of the different drag models is performed for the 0.0549 m diameter slurry pipeline. The research is carried out by using three drag models: Syamlal-obrien, Schiller-naumann and Gidaspow due to their accessibility in the Fluent commercial software. The simulation is performed at mean flow velocity range, Vm= 2–5 ms-1 and solid concentration range, Cvf = 10– 20% (by volume) using computational drag models. The simulated outcomes for solid particle size 440 μm having density 2470 kg/m3 are recorded using Eulerian two-phase model with selected drag models in the computational domain. It has been found that the Eulerian two-phase model with Syamlal O’brien drag model gives the accurate and meticulous results with the published data in the literature. Finally, the simulated outcomes of solid concentration contours, solid concentration profiles and pressure drop are predicted at distinct velocity and solid concentration range for chosen drag models.

The recent paper presents the experimental investigation on material removal rate (MRR) and electrode wear ratio (EWR) of hybrid metal matrix composite of Aluminium 7075 reinforced with 10% by wt. Silicon carbide particles and nanoparticles of magnesium (Al 7075/10%SiC/Mg). Magnesium metal matrix composites are of significant importance nowadays because of the increasing demand of light weight structural material in aerospace and automotive applications. Stir casting process has been used for fabrication of hybrid metal matrix composite. The effect of process parameters on responses such as MRR and EWR are evaluated during conventional EDM and rotary EDM. The pulse duration, peak current, duty cycle, and tool speed are selected as machining parameters. A comparative analysis of conventional EDM and rotary EDM of hybrid composite has been done. Experimental results indicated that the rotation of the tool enhances the flow of dielectric and effective evacuation of the debris from the gap between the workpiece and tool. The result shows increased MRR and reduced EWR with rotary EDM as compared to conventional EDM. This work seems to be of novelty and the findings can be useful for aerospace and automotive industry.

The surface morphology alike lotus leaf has high contact angle and low contact angle hysteresis with respect to water droplet because of nanoscale roughness superimposed on micro order roughness in well-organized manner. The major application of superhydrophobic metallic substrate is in the condensing unit of energy and water harvesting devices. In this work, nanoscale roughness is superimposed on micro-order roughness of Aluminum substrate. The chemical texturing method is used to create micro-scale roughness onto Al surface. However, 0.6 keV Ar ions are irradiated for various time span to fabricate nano order roughness on chemically etched substrate. The roughness of samples is measured by Atomic Force Microscopy and static contact angles and their hysteresis are measured by lab customize Goniometer. It is found that the static contact angle and contact angle hysteresis increases after irradiation on chemical etched surfaces. Multi-scale roughness is observed on irradiated substrate. Results also shows that contact angle increases with increasing time of irradiation. However, maximum change in static contact angle is observed for samples irradiated for 45 s. Eventually, the static contact angle is correlated with its surface roughness. This correlation is vital for optimizing parameter affecting condensation rate in dropwise condensation. Finally, the moist air condensation experiments are conducted to know the condensation efficacy of the irradiated substrate. Also, it is found that the drop sliding frequency on vertical irradiated Al substrate is higher than the chemical etched Al substrate.

Introduction:A key feature of the 'One Health' concept pertains to the design of novel point of care systems for largescale screening of health of the population residing in resource-limited areas of low- and middle-income countries with a view to obtaining data at a community level as a rationale to achieve better public health outcomes. The physical properties of blood are different for different samples. Our study involved the development of an innovative system architecture based upon the physical properties of blood using automated classifiers to enable large-scale screening of the health of the population living in resource-limited settings.Methods:The proposed system consisted of a simple, robust and low-cost sensor with capabilities to sense and measure even the minute changes in the physical properties of blood samples. In this system, the viscosity of blood was derived from a power-law model coupled with the Rabinowitsch-Mooney correction for non-Newtonian shear rates developed in a steady laminar Poiseuille flow. Surface tension was measured by solving the Young-Laplace equation for pendant drop shape hanging on a vertical needle. An anticipated outcome of this study would be the development of a novel automated classifier based upon the rheological attributes of blood. This automated classifier would have potential application in evaluating the health status of a population at regional and global levels.Results:The proposed system was used to measure the physical properties of various samples like normal, tuberculous and anemic blood samples. The results showed that the physical properties of these samples were different as compared to normal blood samples. The major advantage of this system was low-cost, as well as its simplicity and portability.Conclusion:In this work, we proposed making a case for the validation of a low-cost version of a microfluidic system capable of scanning large populations for a variety of diseases as per the WHO mandate of "One Health".

Despite of the fact that Earth’s atmosphere has abundant freshwater inform of moisture, water scarcity is one of the crucial problems especially in humid, hot, and drought prone regions. The conventional systems which extracts atmospheric water are very bulky, incompatible with the existing system, energy intensive, impractical, low water yield and expensive. These adverse effects hinder their deployment for large scale applications. In this manuscript, a water harvesting device is deigned and fabricated for extracting water from moist air. The device uses vertical copper pipes entrenched in horizontal Al fins as the condensing surfaces. All the components of the device functions on solar powered energy. The proposed device is environment friendly, compact, lightweight, low manufacturing, and maintenance cost. The device generate water with turbidity of 40 PPM. Results shows that condensation rates strongly depend on the relative humidity, saturation temperature of the moist air, and degree of subcooling. In this device, the cost of water is estimated as Rs. 10 per liter. This device is efficient for providing drinkable water in hot and humid, water scare regions globally.

Solar energy is a renewable, free, environmental friendly, and inexhaustible form of energy. A number of devices have been developed and tested to harness solar energy. The solar air-heater is one of the thermal energy conversion devices, which collects the thermal energy coming from the sun and transfers it to the air passing through it. Sun rays passing through the top glass surface strikes the absorber plate, which acts as a medium to transfer the thermal energy. Mankind has been in pursuit of technological advancement and efficiency enhancement since the inception of the solar air-heater. Over the past few years, various advancements were made in and around the absorber plate of solar air-heater so as to maximize and enhance its performance. This paper presents a comprehensive review of the recent trends and advances made in the field of SAH for improving the thermal efficiency. Besides this, other methods of performance enhancement have also been discussed.

In this paper, simulation of silica sand-water slurry is carried out through a horizontal mitre pipe bend of 0.050 m in diameter using ANSYS Fluent 16. The simulation of silica slurry was accompanied by using Eulerian two-phase model constrained with RNG K-epsilon turbulence model. The simulation was conducted using silica sand particulates of spherical size 448.5 µm for the volume fraction range 3.94–8.82%. The simulation of silica sand particulates was carried out with water properties available at different Prandtl numbers range, i.e. Pr = 2.14–5.83. The results of silica sand concentration contours and pressure drop were predicted at different mean flow velocity range, i.e. 1.78–4.5 ms−1. It was found that the slurry pressure gradient escalates with increase in Prandtl number and mean flow velocity. Finally, the concentration contours of silica sand slurry for mean flow velocity 4.5 ms−1 at different angles i.e. θ = 0°–90° across the pipe bend are reported and discussed.

In this work, a comparative analysis is provided for technological indicators of various methods of technical levitation. Later, mathematical model was formed for particular cases of the gap of electromagnetic levitation and many composite non-contact mechanisms. This analysis mechanics creates effective contactless mechanisms which help us many aspects of energy and material saving.

Condensation on surfaces with low wettability is of great significance in microfluidics and the fabrication of nanostructures. In this work, condensation process of water vapor from moist air flowing on a mesh-like surface is investigated experimentally at controlled environment condition. In order to execute condensation, temperature difference is increased between the air dew point and Cu mesh surface temperature. The hydrophobicity on mesh-like surface is enhanced using chemical texturing. The static and dynamic surface properties are moderated on this fabricated mesh-like surface with contact angle hysteresis of 16°. Thus, this type of surface is suitable for improving the performances of condensation and to extend their practical applications worldwide.

Water is essential for human survival and is considered as the most essential for our daily life. The major problem in the modern world is water scarcity and contamination of existing water resources. This study proposed a solar-based water generating device from moist air of the hot and humid region. The device is compact with high-water generating capacity per unit volume. The condensing substrate is a super-hydrophobic copper substrate which is cooled by solar-based DC power supply Peltier modules. It is demonstrated in climatic condition of July–August month in Noida and it generated 7.6 ± 2 L of freshwater per day from the atmospheric air. The device is suitable in the areas with moist air all around the year.

Moisture evaporation on porous surface has grown into a dynamic research due to the advancement in building technologies, wooden frames, water purification, baking and cooling purpose. Evaporation on a porous surface involves complex multiphysics coupling heat and moisture transport concurrently. In the present work, numerical simulation of evaporation on the porous surface is carried out on the basis of heat and moisture transport theory. Simulations are carried out using COMSOL Multiphysics software. The simulation result of this model is validated against the analytical solution ensuing good agreement. Post-validation, a parametric analysis of the evaporation on porous surface is done to compute temperature variation, relative humidity variation, mass transfer coefficient and heat transfer coefficient at various regions on the porous surface. These results are useful for sensitivity analysis of various porous materials in the mathematical modelling of evaporation on the flat surfaces.

This issue of International Journal of Vehicle Structures and Systems covers a special issue covering the best papers selected on peer review basis and edited by the Guest Editors as above. These 7 papers are from the research papers presented in the special session on Vehicle Structure and System Design at the 2nd International Conference on Future Learning Aspects of Mechanical Engineering (FLAME - 2020) organised by the Department of Mechanical Engineering, Amity School of Engineering and Technology, Amity University, Noida, Uttar Pradesh, India from 5th August to 7th August 2020. A short biography of each Guest Editor is also provided as further information for this special issue.

In this research work, a surge tank is developed and utilised in the diesel engine for controlling the NOX emission. This surge tank acts as a damper for fluctuations caused by exhaust gases and also an intercooler in reducing the exhaust gas temperature into the diesel engine intake manifold. With the utilisation of the surge tank, the NOX emission level has been reduced to approximately 50%. The developed surge tank is proved to be effective in maintaining the circulation of water at appropriate temperatures. A trade-off has been established between the engine performance parameters including the brake thermal efficiency, brake specific fuel consumption, exhaust gas temperature and all emission parameters including HC and CO.

This study investigates the thermal characteristics of the \(3\times 8\) Li-ion cell arrangement within the battery module numerically at different boundary conditions. Various parameters are considered in the current study, such as different ambient temperatures, inlet velocities, and duct sizes. The battery module is simulated in ANSYS Fluent 19. A three-dimensional computational model is established to analyze the thermal profile of Li-ion cells for different ambient temperatures. The forced air convection method is employed to study the effects of inlet velocities at different ambient temperatures. The thermal performance of the battery module is judged on the capability of the battery module to work within the optimal temperature range of \(0{-}40\,^\circ{\rm C}\). The results indicate that \(3\times 8\) Li-ion cell arrangement at higher ambient temperature ranges works within the optimal temperature range. The thermal analysis of duct sizes shows that \(15{-}20\) mm is the ideal inlet and outlet duct size for \(3\times 8\) Li-ion cell arrangement. This would further give insights into the thermal profiles of \(3\times 8\) cell arrangement, which would aid in designing efficient battery modules with cells operating within the optimal temperature ranges.

Teh primary objective of teh present work is to compare different properties of reinforced Al7075. Boron carbide and silicon carbide (available in powder form) were mixed to teh alloy in different percentages to check their TEMPeffect along wif magnesium present in powdered form. Boron carbide (also non as black diamond) was selected as it is highly robust and TEMPhas good shielding properties against neutrons, me.e., it absorbs them well. It can stabilize teh ionizing radiations and is teh third hardest non substance after diamond and cubic boron nitride. Silicon carbide was selected as it TEMPhas high strength and hardness wif good wear resistance properties. Magnesium is selected because it is teh lightest of all teh metals and TEMPhas good heat dissipation and good damping capacity. Alloy is lightweight and TEMPhas main applications in aircraft industry, automotive parts, and defence applications. Graphite crucible was preheated (to remove teh moisture) to a temperature of 200–300 °C and tan stir casted using stir casting set up. Samples were tan poured in die and tan allowed to cool down. Samples were tan collected from die and after dat mechanical properties were tested (tensile test and hardness test). SEM/EDS and XRD analyses were conducted to briefly study teh microstructure and phase of teh samples prepared.

Dropwise condensation of water vapor present in moist air on copper surface is of significant scientific interest worldwide, for developing an efficient condensing unit of water harvesting via dewing devices. However, it does not prolong for a long duration on these surfaces because of the highly reactive nature of copper. In this work, simple and economically viable methods are described for altering the morphology of copper surfaces which exhibit dropwise condensation for long duration. The durable hydrophobic copper surfaces are fabricated by electrochemical deposition and solution immersion methods on chemically etched copper samples, followed by ion beam irradiation of 15 keV Ne ions at a fluence of 1017 ions/cm2. The roughness of tailored samples is measured using atomic force microscope and contact angle measurements are performed for measuring the static contact angle of deionized water droplets on these modified surfaces. The results show that the irradiated surfaces have low contact angl...

The current paper simulates the thermal management of Li- ion battery modules of 6x5, 3x10 and hexagonal array arrangements. High-fidelity 3-D CFD simulation is carried out using commercial CFD software ANSYS ICEPAK®. An experimental study of battery array arrangement of Li-ion was carried out for validating the simulation results. Forced air convection mode was used for transporting energy from the battery module to the environment. Post-validation, the thermal analysis of the various array arrangement of battery system was investigated at various environmental conditions. It was realized that the hexagonal array arrangement was more effective than the 6×5 and 3x10 cell arrangements for controlling the temperature within the cells and battery module. The convective heat transfer coefficient is optimized to maintain the optimal temperature ranges of Li-ion cells for different inlet velocities and ambient temperatures. Finally, Inlet velocities and duct sizes for different ambient temperatures were suggested for the effective and efficient functioning of Li-ion battery array arrangement for electric vehicles.

Fossil fuels are the major source of energy in developing countries but problems like generation of greenhouse gases and financial burden on the economy due to import are the problems associated with it among others. The use of renewable energy sources like solar energy is increasing now a days but problems like fluctuation of energy in day and time dependent availability hindered its implementation at large scale. This problem can be overcome by the application of solar thermal battery that store the solar energy in various forms. In this paper, state-of the-art of energy storge and their issues and challenges of in form of sensible, latent and thermo-chemical system were presented. Later, experimental study of tailoring paraffin wax for storing the solar energy in form latent heat were presented. It is concluded that pure paraffin wax is not appropriate energy storage material in form latent heat because of low thermal conductivity. State of the art of enhancing the thermal conductivity of various phase change materials were also reported.

Interconnects are used in solid oxide fuel cells (SOFCs) for connecting the fuel cell stacks. These interconnect are coated with spinel oxides to prevent the formation of a native scale oxide layer under high heat flux conditions. Generally, the SOFCs are subjected to thermal shock during their operation. At the interfaces of these coating, shear stresses and peeling stresses were induced due to a mismatch between the thermal expansion coefficient of coating and native scale thickness. These stresses peel off the coating layers which affect the interconnect performance. In this paper, the effect of varying native scale thickness at two different coating thicknesses on the shearing stress and peeling stress of the interconnects is analytically calculated along the two different interconnect thicknesses. The oxidation kinetics of spinel-coated SOFCs interconnects with the analytical equations relating native scale thickness with the time of SOFCs operation were reported. As per our analysis, we concluded that these stresses majorly depend on the thickness and the mechanical properties of the interconnects, native scale and a coating layer.

The transition to electric mobility, owing to their proposition as a solution to the environmental qualms of rising levels of pollution due to the utilization of conventional sources of energy (fossil fuels), has directed the attention of researchers to the main energy storage system of the electric vehicles that is batteries. Due to their efficient peak and average power delivery, batteries are the preferred choice for energy storage. With Lithium-ion chemistry proving to be an efficient battery technology in terms of energy density, specific power, safety, durability, and reduced emissions; the requirements for their optimum operation include a temperature range of 15°C-35°C and a uniform temperature profile, which in turn affects the vehicle performance are a cause of concern. This underscores the importance of a design of an effective battery thermal management system (BTMS). A BTMS is tasked with the maintain a fixed range of temperature throughout the battery operation, thus enhancing its life and efficiency. A variety of BTMS designs have been presented based on different types of medium, power consumption and thermal cycle. The objective of this work is to analyse the different BTMSs for different arrangements of cells in a battery module using CFD and utilize the results of the analysis to propose the optimum, cost-effective, and low maintenance BTMS for enhanced performance of the battery module. The CFD analysis is performed the assessment of the airflow using ANSYS Fluent in the BTMS. The analysis of the air flow through the battery module can give a better insight on changing the packing arrangement of cells and positioning of active or passive thermal management systems.

In dropwise condensation, the released latent heat passes through the static and sliding droplets to the condensing surface at a rate limited by various thermal resistances. In the present work, numerical simulation of heat transfer through a droplet is carried for one under static and sliding condition. 3-D governing equations with appropriate boundary conditions are solved for the surface, promoter layer and droplet included within the computational domain. Simulations are carried out using an in-house CFD solver. The simulation results are validated against the available data and are found in good agreement. The observations of the present work are: (a) heat transfer through the droplet achieves steady state over a timescale of micro-seconds, (b) the heat fluxes of deformed and equivalent spherical-cap droplet are found to be equal, (c) Marangoni convection is significant for Ma ≥ 2204, (d) convection is the dominant mode of heat transfer during drop slide-off (e) constriction resistance is insignificant for a copper surface of thickness ≤ 2 mm, (f) average heat flux increases with increasing contact angle, interfacial heat transfer coefficient, degree of subcooling and Reynolds number; however, it decreases with increasing Prandtl number of the liquid. These results are useful for sensitivity analysis of various thermal resistances in the mathematical modeling of dropwise condensation underneath inclined surfaces.

Traffic congestion is a huge problem in many big cities around the world. This traffic congestion can affect the economy of a country, increase cost, slow down development and increase the environmental pollution. This research deals with the development of fuzzy logic based traffic signal which has dynamic cycle length. Development of such type of traffic signal is based on fuzzy logic. The traffic signal control system considers the uncertainty and vagueness of information about the input and output parameter values of the system. Fuzzy logic can easily handle such type of vagueness and uncertainty. The input parameters which are applied on fuzzy logic based traffic signal control are traffic density and traffic flow. The fuzzy traffic signal controller uses the input parameters and applies these inputs to fuzzy inference system to calculate the cycle length. The simulation is carried out using MATLAB software. The inference system used in fuzzy logic system is Mamdani inference system. According to the traffic conditions the cycle length of traffic signal is changed which decreases the waiting time of vehicles at the intersection. Keywords: Cycle Length, Fixed Time Traffic Signal Control, Fuzzy Logic, Inference System, Simulation