@techreport{oai:jaxa.repo.nii.ac.jp:00044941, author = {若松, 義男 and 田村, 洋 and 鈴木, 昭夫 and 小野, 文衛 and 豊川, 光雄 and WAKAMATSU, Yoshio and TAMURA, Hiroshi and SUZUKI, Akio and ONO, Fumiei and TOYOKAWA, Mitsuo}, month = {Oct}, note = {The high frequency instability of a JP-4 fuel and liquid oxygen rocket combustor, especially the effects of this instability on heat transfer augmentation to the chamber wall, was studied. The FOF triplet type injector element and two chambers with different lengths were used in the experiments. Both chambers delivered a 10kN thrust at a 3.5MPa chamber pressure. The pressure oscillation generated spontaneously was identified as being a longitudinal first mode. The ratio of rms pressure amplitude to average chamber pressure observed in unstable combustion was 0.23 at most. In order to obtain stable combustion or weak unstable combustion, a damping device based on Crocco’s theory of longitudinal high frequency instability was designed and used successfully. The heat flux to the wall increased six to seven times at most due to the instability. It was shown that the increase of the bulk heat transfer coefficient was proportional to the square root of rms pressure amplitude when the effective temperature, based on the frequency of oscillation, was used. Various considerations, including the effect of solid carbon particles, suggests that Dent’s model of convective heat transfer augmentation is more reasonably consistent with the experimental results than is Hanby’s model. The time average static pressure along the chamber axis increased downstream after it had first decreased. Theoretical analysis of the periodically oscillating one-dimensional flow showed reasonable agreement with the experimental results., 資料番号: NALTR0684000, レポート番号: NAL TR-684}, title = {High Frequency Instability in a Lox-Kerosene Rocket Combustor (Effects on Heat Transfer Augmentation)}, year = {1981} }