Research On The Evaluation Method Of Aircraft Airworthiness Lateral Noise

CCAR-36(China Civil Aviation Regulation No.36),NOISE STANDARDS: Aircraft Type and Airworthiness Certification require that it is necessary to carry out measurement noise for approach,sideline and take-off measurement points of civil aircraft.The measurement points of approach noise and take-off noise are fixed and convenient for measuring,however,the layout of the baseline measurement points for the lateral noise during take-off need to be studied and determined based on empirical data.Therefore,the effective perceived noise level of each point on the aircraft sideline based on the ANP database is analyzed and calculated,and the research technical route about evaluation method of aircraft airworthiness lateral noise is proposed.Finally,the scheme of setting up the measurement points for aircraft lateral noise is determined.By using this scheme,the maximum lateral noise level and location of lateral noise can be obtained more accurately during the measurement of noise airworthiness.Reasearch and analyz the algorithm of aircraft noise isoline provided by the European Civil Aviation Conference,and supplement the part of the algorithm,and then apply it to the calculation of noise levels at each point on the sideline of aircraft.The prediction and evaluation of the lateral noise of an aircraft is carried out and it is based on the data of the aircraft noise and performance database ANP provided by the SAE International.The internal relationship between the noise level of the sideline and the location of the noise measurement point is analyzed,and then the 91 point setting scheme for noise measurement point on the sideline is preliminarily established.The scheme is used to predict the sideline noise,and the airworthiness data are used to verify the effectiveness of the scheme,so the 7 point setting scheme for noise measurement point on the sideline based on that is determined.Finally,the B737-800 and A320-211 aircraft are selected for practical application,and the feasibility is verified.To further optimize the scheme,the 9 point setting scheme for noise measurement point on the sideline is established.The research results can be used to measure the lateral noise of large domestic aircraft,such as C919,it could improve the accuracy of the lateral noise in the process of noise airworthiness examination,and shorten the time of noise airworthiness examination.