The Research Of The Aircraft Flyover Noise Level On Cutback Thrust Prediction Algorithm

The aircraft of C919 had been assembled in Shanghai in 2015 assembly line,and is expected to achieve the first flight by the end of 2017.The noise certification is a type certification airworthiness forensics important work,the use of reduced thrust aircraft flyover noise level prediction algorithm is an effective measures to reduce aircraft noise airworthiness certification costs and shorten the approval cycle.In December 2016,China Commercial Aviation and Russian Joint Aerospace Manufacturing Co.,Ltd.jointly developed C929 wide-body aircraft.In its design stage,The noise prediction algorithm can estimate its noise situation to determine the design parameters.The basic theory of jet noise airworthiness certification were studied,and the idea of predicting the aircraft flyover noise level reduced thrust the idea binding principles of the engine.In order to obtain flyover noise level before the new aircraft flight and reduce the cycle of the new aircraft noise to the examination and approval of qualified and save the consumption of resources,the aircraft flyover effective perceived noise level prediction algorithm was studied;Firstly,this paper deduces the formula of effective sensory noise based on the basic formula of aircraft engine principle and sound pressure level,and uses the relevant control parameter to standardize the aircraft reduction thrust flyover noise level prediction algorithm;Secondly,access to the aircraft manufacturer's official website models of the basic control parameters and the European Aviation Safety Agency official website of the reduced thrust takeoff over the effective sense of noise certification,Taking the Boeing series and the Airbus series aircraft as an example,the prediction algorithm is used to calculate the effective noise of the thrust reduction,Compared with the EASA certified thrust flyover noise value,the accuracy of the algorithm is verified,and the algorithm is used to calculate and calculate the influence of the relevant parameters on the effective sensory noise.Finally,this paper uses the reduced thrust flyover noise level prediction algorithm and Microsoft Visual Studio 2010 to complete the application design of the aircraft thrust reduction flyover noise level forecasting system,and realizes the C919 aircraft's thrust reduction flyover noise level prediction calculation.This paper can effectively estimate theefficiency of C919 aircraft by reducing the effective noise level and improving the efficiency of airplane airworthiness certification.