Numerical investigation of a new short isolator with bleed slots

An isolator with bleed slots was designed to reduce the length of the isolator and to improve the isolator maximum back pressure.The slots were placed on the corner of the lower wall at the isolator entrance.Computational fluid dynamic simulations were performed on the isolator.Numerical results indicated that the overall length of the isolator could be reduced by 30% for the isolator with bleed slots at the same back pressure.The maximum back-pressure is improved by 8% for the isolator with a bleed slot which can withstand a maximum back-pressure of 3.74 times static pressure,but the baseline isolator could only withstand a maximum back-pressure of 3.46 times static pressure.The reasonable position of slots should be near the corner in the forepart of the isolator.The performance of the isolator does not change lineally when the inclined angle of the slots alters.When the bleed slot works as supercritical operation,the bleed pressure has great influence on the isolator performance.When the bleed slot works as subcritical operation,the bleed pressure has little influence on the isolator performance.