Entropy generation minimization analysis of two immiscible fluids

The entropy generation of two immiscible fluids is investigated in a conjugate heat transfer system. The velocity and temperature fields are analytically obtained by solving the momentum and energy conservation equations. These analytical solutions are used to calculate the local and total entropy generation rates. Based on the entropy generation minimization (EGM), the total entropy generation of two-layer thermal flow system can be minimized by using the method of single variable optimization. Compared with the classical single-layer thermal flow system, the effects of viscosity ratio, thermal conductivity ratio and density ratio between upper and bottom fluids on the total entropy generation have been given special attention. Result shows that the total entropy generation can be minimized for the specific values of physical parameter ratio when the other parameters keep constant. Besides, it is also found that the total entropy generation of two immiscible fluids can be smaller than that of single fluid. This implies that the irreversible losses can be reduced in the present two-layer thermal flow system. And this reduction of irreversible losses can be helpful in improving the thermal performance of system. The present study is aimed at achieving a theoretical prediction to choose beforehand the appropriate types and heights of two immiscible fluids.

Automated summary

This study investigates the entropy generation of two immiscible fluids in a conjugate heat transfer system and finds that the total entropy generation can be minimized in a two-layer thermal flow system. Specific values of physical parameter ratios can lead to this minimization of entropy generation.