Effect of angle of attack on the performance of the supersonic intake for High Mach Integrated Control Experiment (HIMICO)

Experimental, numerical and theoretical investigations are carried out to grasp the effect of angle of attack (AoA) on the performance of the supersonic intake for High-Mach Integrated Control Experiment, HIMICO. The results of theoretical analysis using simple shock wave (TFD) suggests that mass capture ratio (MCR) and total pressure recovery (TPR) are increased with positive angle of attack. In fact, comparing the result of 2.5 deg AoA with that of −2.5 deg AoA gained by CFD, MCR and TPR become 21pt and 5pt larger when the nozzle throat height (HNT) is 12.5 mm. The main factors of these phenomena are the increased projected area of the intake entrance and the change of the oblique shock system. On the other hand, TFD incorrectly estimates HNT and TPR in critical state because the pseudo-shock wave is generated instead of the terminal normal shock wave considered in TFD. So the characteristics of the pseudo-shock wave are investigated by CFD. As a result, it was found that the total pressure loss due to the pseudo-shock wave is larger than that of the normal shock wave, and that the total pressure loss becomes smaller with positive AoA due to the decrease in the Mach number at the intake throat. Using the CFD results, we created a model to estimate TPR and HNT in the critical state from the relational equation between the intake throat Mach number and the total pressure loss due to the pseudo-shock wave.