Pressure Fluctuations (Buzzing) and Inlet Performance of an Airbreathing Missile

Abstract

The performance of a rectangular ramjet inlet has been investigated experimentally. The main objective of the study has been to analyze the inlet flow before and during buzzing. Experiments have therefore been carried out with an inlet without and with boundary-layer bleed at an angle of attack of 0 deg and at Mach numbers ranging from 2.5 to 3.5 in the Trisonic Wind Tunnel Cologne. The inlet flow was analyzed with schlieren images and unsteady pressure recordings, where different pressure fluctuations are detected. The results show that the inlet flow is highly unsteady even at supercritical condition and that the subsequently added boundary-layer bleed permits better pressure recovery and a delay in inlet buzzing.