Innovative concept for cascade thrust reverser without blocker doors

This paper reports the progress being made on an innovative thrust reverser concept for potential use on commercial turbofan aircraft. The concept employs a unique application of fluidics by using the readily available high-pressure engine core flow to divert the much larger fan flow out through a cascade opening. In our simulated 5:1 bypass ratio fan engine, we have been able to turn 100% of the fan flow into the cascade opening by injecting a mass flow that is less than 3% of the fan flow. This amount of core flow bleed is well within current engine capabilities. With a simple cascade vane design, we have achieved more than 40% thrust reversal. This performance is comparable to conventional blocker door configurations without suffering the corresponding weight, mechanical complexity, and aerodynamic cruise penalties. This report describes our experimental and analytic study, and states our conclusions on the effects of various geometric and aerodynamic parameters.