Temperature distribution and classical entropy generation analyses in an asymmetric cooling composite hollow cylinder with temperature-dependent thermal conductivity and internal heat generation

Abstract

Entropy generation rate is directly related to exergy destruction and is therefore to useful energy. This study investigates temperature distribution and local and total entropy generation rates within a composite hollow cylinder with temperature-dependent thermal conductivity and internal heat generation. The internal heat generation is considered constant but different for inner and outer materials. Two cases are examined: (a) constant temperature boundary conditions and (b) asymmetric convective cooling boundary conditions for inside and outside surfaces. The general solution for the system of equations is analytically found, and constant parameters are numerically calculated for each case. Moreover, complete analytical solution is performed for cases with temperature-independent thermal conductivities. For the first case, temperature distribution and entropy generation depend on eight parameters, and for the second case, the reported data depend on ten thermophysical parameters. After verifying the solution procedure, a comprehensive study is performed for temperature distribution and total entropy generation rate with various values for different parameters. Thus, the new proposed data and graphs in this study provide a remarkable tool and at the same time retain suitable simplicity for engineers. The results should be useful in a number of engineering applications and considerably ease the processes of choosing geometrical parameters together with environment temperature or heat transfer coefficient when dealing with composite hollow cylinders with two-layer materials for less entropy generation, that is, less exergy destruction.