Effect of honeycomb structure layout on heat transfer performance of a high-temperature wind tunnel storage heater

To meet the demand for stable high-temperature air sources in hypersonic ground testing, this study employs three-dimensional unsteady conjugate heat transfer simulations to investigate the thermo-fluid performance of honeycomb regenerators with different pore densities under constant porosity and pitch-to-diameter ratio constraints. The results show that the high-density configuration exhibits the best thermal output and sustained heat-supply capability. At the end of 120 s of discharge, its outlet temperature is 74 K higher than that of the low-density configuration, while its outlet-temperature drop over 60-120 s is reduced by 39%. At 120 s, its solid-temperature non-uniformity decreases from 18% in the upstream section to 1.7% in the downstream section. Under high-flow conditions, the high-density configuration also shows lower sensitivity to flow-rate disturbances and achieves a 13% improvement in energy extraction efficiency. However, this thermal advantage is accompanied by a greater flow penalty, with an average resistance coefficient 2 times that of the low-density configuration.