Enhancing heat transfer performance analyses of a hydrogen-fueled meso-combustor with staggered bluff-bodies

To improve the energy conversion efficiency of a thermo-photo-voltaic system, there is a need to optimize the combustor performance. This work considers applying staggered bluff-bodies to enhance thermal performance in a hydrogen-fueled meso-combustor. Effects of the equivalence ratio phi, the staggered bluff-bodies dimensionless height h, and the pitch ratio PR are numerically assessed and analyzed. To characterize the heat transfer intensity inside the channel, an average Nusselt number is introduced. Results show that the implementation of staggered bluff-bodies can generate longitudinal vortices, thus promoting mixing and enhancing the heat transfer performance significantly. Up to 73 K increase in the mean wall temperature (MWT) can be achieved. Meanwhile, MWT shows a non-monotonic dependence on phi, but the Nusselt number is found to vary monotonically with phi. Furthermore, increasing h is shown to be accompanied by a high Nusselt number, leading to a more uniform and higher MWT. Finally, it is shown that the PR of the staggered bluff-bodies plays a critical role in optimizing the system's thermal performance, and a low PR is more favorable but associated with a high pressure loss. The insights gained from this study may be of assistance to design a high-efficiency power system.