Entropy generation in impinging flow confined by planar opposing jets

In this paper, entropy generation in impinging flow confined by planar opposing jets is investigated systematically for the first time. Different from previous works on entropy generation for practical flows, in this study the lattice Boltzmann method, which is more suitable for massive parallel computing, is used to solve the governing equations for flow field as well as the entropy generation equation, instead of traditional numerical methods. The effects of the Reynolds number 10 ≤ Re ≤ 500 and the distance ratio between opposing jets 2/5 ≤ W/L ≤ 4/5 on entropy generation are revealed. It is found that the local entropy generation number is more sensitive to the variation of W/L than Re when Re > 50. The total entropy generation number increases exponentially with Re but decreases as a power function of W/L. In addition, the entropy generation will receive significant influence from the damping traveling pressure wave during the transient state and the maximum emerges when the gas ejected from the top and bottom jets begins meeting and impinging.