Performance analyses on Telsa-valve structured meso-combustors in presence of ammonia-hydrogen/air combustion for thermophotovoltaic applications

In this study, a meso-scale combustor featuring Tesla valve structure is considered, with a comparative analysis conducted between the Double-layer Tesla Valve (DLTV) combustor and the Single-layer Tesla Valve (SLTV) combustor. Additionally, the reverse flow (RF) and forward flow (FF) configurations of the Tesla valve structured combustors are examined and compared. The thermal performance, nitrogen oxide emission characteristics, and internal flow dynamics during the combustion of the ammonia-hydrogen-air mixture are numerically investigated. The ammonia blend ratio (Φb) for a stable combustion within the RF structure can reach 20 %, whereas the Φb for a stable combustion in the FF configuration is 10 %. The increased flow resistance inside the RF structure promotes more complete fuel-depleted combustion, thereby increasing the wall temperature. In contrast, the FF structure, due to its lower flow resistance, extends the flame area of the mixed fuel, thereby improving wall temperature uniformity. The DLTV structure is shown to improve the wall temperature uniformity by over 55 % across varying flow rates. Both DLTV and SLTV structures demonstrate a significant enhancement in the combustor's thermal performance and overall performances characterized with Nusselt and Peclet numbers. While the DLTV exhibits a more pronounced improvement in thermal performance, the SLTV achieves better overall performances owing to its lower pressure loss (Ploss).