A subscale, research rocket thrust chamber operating with cryogenic oxygen and hydrogen exhibits self-excited transverse-mode instabilities with amplitudes of more than 80% of the steady combustion chamber pressure (peak-to-peak) for some operating conditions. During unstable combustion, an increase in the integral heat flux into the water-cooled combustion chamber walls of 20–40% with respect to stable conditions was experienced. A model was derived to predict changes in the axial heat flux profile considering only the dependence of flame length on the amplitude of transverse acoustic oscillations. The model predicts an increase in heat flux in the upstream part of the chamber by up to a factor of 7. This drastic increase is in agreement with past observations of rocket engine failures due to instabilities, in which the structural damage is commonly observed on the faceplate and the walls adjacent to the injection plane. The model also predicts a peak increase in integral heat flux of up to about 25%. While falling short of the peak experimental value of 40%, it nevertheless suggests that flame length is the dominant influence on the distribution of thermal loads in this study.

使用低温氧气和氢气运行的亚尺度研究火箭推力室表现出自激横向模式不稳定性，在某些运行条件下，其振幅超过稳定燃烧室压力（峰峰值）的 80%。在不稳定燃烧期间，相对于稳定条件，进入水冷燃烧室壁的整体热通量增加了 20-40%。推导出一个模型来预测轴向热通量分布的变化，仅考虑火焰长度对横向声学振荡幅度的依赖性。该模型预测腔室上游部分的热通量将增加 7 倍。这种急剧增加与过去对火箭发动机由于不稳定性而发生故障的观察结果一致，其中结构损坏通常在面板和与注入平面相邻的壁上观察到。该模型还预测积分热通量的峰值增加高达约 25%。虽然低于 40% 的峰值实验值，但它表明火焰长度是本研究中热负荷分布的主要影响因素。