Entropy generation analysis of two-dimensional high-temperature confined jet

Abstract

In high-temperature systems, thermal radiation becomes the dominant mode of heat transfer. The analysis of entropy generation mechanism is very important to optimize the second-law performance of these energy conversion devices. In this paper, the entropy generation in a two-dimensional high-temperature confined jet flow is analyzed. The computation of combined radiation and convection heat transfer is carried out with the help of a CFD code, and the entropy generation due to heat transfer and fluid friction is calculated as post-processed quantities with the computed data of velocity, temperature and radiative intensity. Numerical results show the entropy generation due to radiative transfer cannot be omitted in high-temperature systems such as boilers and furnaces, in which thermal radiation is one of the main modes of heat transfer. In the case that the temperatures of the inlet gas and the top and bottom are not changed, the total entropy generation number decreases with the increase of jet Reynolds number and Boltzmann number, respectively. For enhancing heat transfer and advancing energy conversion efficiency, large jet Reynolds number and Boltzmann number should be selected.