Optimal heating strategy for minimization of peak temperature and entropy generation for forced convective flow through a circular pipe

Abstract

Fundamental insight on the minimization of entropy generation and maximum temperature is important for efficient performance and proper design of thermal systems. One of the key factors that dictate the entropy generation and temperature within a thermal system is the applied heat source and therefore appropriate heating strategy that minimizes the peak temperature and entropy generation needs to be determined. In this work, non-uniform distribution of heat flux applied to the wall of a circular tube undergoing laminar forced convective flow of a high Prandtl number fluid has been investigated numerically to optimize the heating strategy which results in minimum entropy generation and peak temperature as compared to the uniform heating. Various heat flux configurations are evaluated for the same amount of total heat rate and comparative assessment between the different cases has been made in terms of peak temperature and entropy generation. In terms of achieving both minimum peak temperature and entropy generation simultaneously, the periodic heat flux condition (sinusoidal with number of waves greater than or equal to 100) can be recommended as the optimum heating strategy for typical thermal system.