Computation of Variable Noise Reduction System Efficiency for Supersonic Civil Aircraft During Takeoff

Abstract

The noise of next-generation supersonic civil aircraft can become a significant nuisance for the population in the vicinity of airports. This study investigates the efficiency of the noise control approach for a notional supersonic civil aircraft at takeoff, based on the implementation of a variable noise reduction system (VNRS) with thrust control. Noise levels are computed with a decoupling approach, where the engine noise data and the flight trajectory are calculated independently. It is shown that implementation of the VNRS for the supersonic civil aircraft could lead to a reduction in the certification noise levels at the lateral and flyover measurement points by about 4 EPNdB. The effect of VNRS on noise levels for two allowable positions of the lateral certification point (on the sideline and on the extended runway centerline) is considered and compared for the first time. It is found that the cumulative noise reduction at the flyover and lateral certification point due to the VNRS is larger by 0.8 EPNdB for the position of the lateral certification point on the sideline than for the position on the extended runway centerline.

Keywords

• aeroacoustics
• noise reduction
• supersonic civil aircraft
• takeoff
• VNRS