Numerical investigation for the short isolator with a ramp under asymmetric incoming flow

An isolator with a ramp was designed to improve the performance of the isolator or to reduce the length of the isolator. The ramp was placed on the lower wall at the isolator entrance. Computational fluid dynamics simulations were performed on the isolator. Numerical results indicated that the maximum back-pressure is improved by 7.8% for the isolator with a ramp which can withstand a maximum back-pressure of 3.73 times static pressure, but the isolator without a ramp could only withstand a maximum back-pressure of 3.46 times static pressure. The overall length could be reduced by 35% for the isolator with the ramp, and the ramp devices is more effective on the lower wall than on the upper one in improving the performance of the isolator.