Entropy analysis in single phase nanofluid in square enclosure under effectiveness of inclined magnetic field by executing finite element simulations

Abstract

One of the important phenomena concerning with dynamical and thermal attributes of heat transferring liquids is the measure of randomness generated at molecular level. This randomness in the system is generated due to presence of multiple factors which includes extensive heat transfer, strong magnetic field and viscous diffusion. To control and minimize disorder ness the concept of entropy is taken into account. Minimization in entropy is valuable in optimization of design objectivity in engineering structures. In addition, it measures and controls exergy loss to generate highly efficient systems likes heat exchangers, heat pumps, power plants, nuclear reactors, air conditioners and so many. So, the prime objective of this work is to analyze entropy in square enclosure filled with water and containing Copper (Cu) particles. Convection in the considered physical domain is generated by providing uniform temperature at upper wall while keeping rest of boundaries cold. In view of velocity field distribution is concerned all the extremities of cavity are at no slip condition. Inclined magnetic field is also employed to measure change in entropy due to magnetization. Formulation of problem expressing thermophysical relation of inducted nanoparticles in manifested in the form dimensionless representation. Patel and Brinkman models for effective thermal conductivity and viscosity are opted to visualize their effectiveness in entropy change. Finite element computations are performed to simulate results showing the impact of flow controlling parameters on associated distributions. Three different types of entropy namely, magnetic, thermal and viscous are measured against different parameters. Quantity of interest like average heat flux coefficient is also measured. It is deduced from the analysis that by increasing nanoparticle volume fraction thermal entropy increases whereas viscous and magnetic entropy uplifts. In addition, it is noticed that by increasing Hartmann number entropy and velocity of fluid decrements. Uplift in temperature magnitude is observed against elevating values of Rayleigh number. It is concluded that employment of magnetic field will assist in controlling flow, thermal and irreversibility phenomenon.