In this paper, the behavior of the plenum pressure behind a transpiration-cooled porous material sample after an incident surface heat flux to the sample is analyzed in experiment and theory. Two porous materials, zirconium diboride and carbon/carbon, were characterized using the pressure-based noninteger system identification method. The resulting impulse responses are analyzed based on two numerical models. One model calculates a plenum pressure impulse response by modeling the porous sample’s heat conduction. A second model considers an additional plenum behind the sample and allows a changing mass flow rate through the sample. The experimentally obtained impulse responses show a stronger response for increasing coolant mass flow rates. Both models cover this trend, essentially depending on the volumetric heat transfer coefficient. However, only the second model allows the entire rebuilding of the experimental data. The plenum pressure impulse response for a transpiration-cooled system depends not only on the material parameters of the porous sample, but also on the volume of the plenum. The reason is that the flow rate changes through the porous sample although the mass flow rate at the controller always stays constant.

在本文中，通过实验和理论分析了蒸腾冷却的多孔材料样品在入射表面热通量之后的增压压力行为。使用基于压力的非整数系统识别方法表征了两种多孔材料，即二硼化锆和碳/碳。基于两个数值模型分析所得的脉冲响应。一种模型是通过对多孔样品的热传导进行建模来计算充气压力脉冲响应。第二种模型考虑了样品后面的额外气室，并允许通过样品的质量流率发生变化。实验获得的冲激响应显示出对于增加冷却剂质量流量的更强响应。两种模型都涵盖了这一趋势，基本上取决于体积传热系数。然而，只有第二个模型才能完整重建实验数据。蒸腾冷却系统的气室压力冲激响应不仅取决于多孔样品的材料参数，还取决于气室的体积。原因是尽管控制器上的质量流量始终保持恒定，但通过多孔样品的流量却发生了变化。