Browsing by Author "Mohamed M. Awad"

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A numerical study of a moving boundary problem with variable thermal conductivity and temperature-dependent moving PCM under periodic boundary condition
(Springer Science and Business Media Deutschland GmbH, 2022) Vikas Chaurasiya; Rajneesh Kumar Chaudhary; Mohamed M. Awad; Jitendra Singh
The work in this paper concerns the study of a one-phase moving boundary problem with size-dependent thermal conductivity and moving phase change material. We have considered a time-dependent boundary condition at the surface y= 0 and a temperature-dependent moving phase change material which later both assumed in periodic nature. A quadratic profile for temperature distribution is assumed to solve the problem numerically via heat balance integral method. In a particular case, we compared our results with exact solution and found to be closed. The effect of various parameters either on temperature profile or on tracking of melting front are also discussed in detail. The parameters physically interpret that transition process becomes fast for a higher value of Stefan number or/and Peclet number while there is a small delay in the propagation of melting interface for larger value of either amplitude of moving phase change material or amplitude of periodic boundary condition. Furthermore, we discuss a comparative study on temperature profile as well as on moving melting front in case of standard problem, moving boundary problem with constant thermal conductivity and presence of convection, and moving boundary problem with variable thermal conductivity and presence of convection and obtained result shows that the transition process is faster in case of moving boundary problem with constant thermal conductivity and presence of convection and is slower in case of moving boundary problem with variable thermal conductivity and presence of convection while it is between them in case of standard problem. © 2022, The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.
A numerical study on the thermal response in multi-layer of skin tissue subjected to heating and cooling procedures
(Springer Science and Business Media Deutschland GmbH, 2022) Rajneesh Kumar Chaudhary; Vikas Chaurasiya; Mohamed M. Awad; Jitendra Singh
This article deals with studies for the behavior of the temperature distribution in multi-layer skin during thermal injuries and its first aid treatment under generalized boundary condition. The finite difference scheme is used to estimate the temperature profile over time and distance. The skin is damaged by heating via generalized boundary condition, after that first aid treatment is applied by cooling phenomenon via the different cold temperature of liquids, the stability of numerical scheme has been discussed, and are also validated the numerical code accuracy by comparison the obtained results with the previous reference results. In the first aid treatment by cooling, the temperature at DS interface is increased constantly over time for a few seconds, then after that, the temperature goes down. The temperature rises along with distance as long as the heat effect is present in the skin, when the heat effect has vanished, the temperature in the skin starts to decrease. During cooling, the heat effect is decreasing faster for the second kind boundary condition in comparison to the first and third kind boundary conditions. It is observed that with a higher blood perfusion rate, skin transfers more heat into the blood due to a convection process, and for this reason, a large amount of heat can be carried away from the skin. The skin burns with 100 oC for 15 s and then we applied first aid treatment by cooling with 0 oC water. Then, it was observed from the mathematical results that 41 s of time is sufficient for cooling to save the rest of the living part of the subcutaneous tissue. The effect of blood perfusion rate, heating and cooling procedures, and generalized boundary conditions are discussed in detail and the results are presented graphically for the analysis of the behavior of the temperature response in multi-layer skin. © 2022, The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.