極超音速統合制御実験（HIMICO）用インテークで発生するバズ現象に関する実験的研究

抄録

The effect of the nozzle throat height (HNT) on the buzz characteristics, which occurs on the ramjet engine for High Mach Integrated Control Experiment (HIMICO), is experimentally studied. The ramjet engine is composed of a variable rectangular intake, a combustor and a variable nozzle. The freestream Mach number of the wind tunnel is set at 3.4. The unsteady static pressure inside the intake is measured and the movement of the shock waves are visualized by the Schlieren imaging. Results show that the frequency of the buzz increases with the decrease of HNT. The temporal change of the static pressure shows that the smaller HNT accelerates the rise of the static pressure, but it does not affect the reduction speed. Therefore, it becomes clear that the cause of the buzz frequency change is the rising speed of the static pressure. Results of the pressure measurement also show that the minimum value of the static pressure inside the intake is not affected by the value of HNT. The results of the Schlieren imaging suggests that the shock wave structure when the leakage diminishes is the same regardless of the value of HNT. The static pressure inside the intake is mainly determined by the shock wave structure at the entrance of the intake and the free stream condition, so the value of the minimum static pressure does not depend on HNT.