Experimental Investigation for Short Isolator with Swept Ramp under Asymmetric Incoming Flow

In order to improve scramjet isolator resistance to back pressure capability and shorten its length,an isolator with a swept ramp is designed.The swept ramp is placed on the lower wall at the isolator entrance and is apart from the isolator entrance about 15 percent of the isolator length.Experiment is conducted in a blow-down supersonic wind tunnel at free incoming flow Mach number of 1.98.Experimental results indicate that the maximum back pressure is improved by 9.89 percent for the isolator with a swept ramp,thus withstanding a maximum back pressure of 3.901 times static pressure,and the isolator without a ramp could only withstand a maximum back pressure of 3.55 times static pressure.The length of the isolator with a swept ramp is reduced by 15 percent at the same back pressure.therefore the total pressure recovery ratio of the isolator with the swept ramp is 0.710,the baseline isolator's total pressure recovery ratio is 0.694,The total pressure recovery ratio of the isolator with a swept ramp is improved by 2.3 percent.