Wind tunnel experiment of the influence of dynamic change of attack angle on start property of sidewall compression scramjet inlet

In order to explore how the change of attack angle at different frequencies influences the start property of inlet,this paper conducted a wind tunnel experiment for the sidewall compression scramjet inlet with Mach number 3.85 and attack angle at different frequencies.The sidewall compression scramjet inlet,with designed Mach number 6 and start Mach number 2.5,was subject to several flow tests,when attack angle changed from 0°to 8.15° again down to 0°,with the frequency at 0.8,1.6,3.2 Hz and 6 Hz,respectively.Results show that at each frequency,the inlet in a periodic oscillation succeeds to go through a start-unstart-restart process.With the increase of frequency,attack angle gradually goes up in the first periodic oscillation,and sharply goes down in the proceeding periodic oscillation.