Research On Prediction Method Of Jet Noise On Aircraft Approach

The impact of aircraft noise on people’s lives has drawn increasing attention,The rapid development of China’s civil aviation industry at this stage also puts forward higher requirements for airworthiness certification.The validation of noise is also an important step in airworthiness validation.The traditional noise worthiness certification work is relatively inefficient and occupies a lot of manpower and financial resources.Jet noise accounts for a large proportion of engine noise.In this paper,the effectiveness of jet noise in predicting flight status is verified by predicting the jet noise of aircraft during the approach,Which can replace traditional noise airworthiness certification procedures.In this paper,ANOPP’s STONE algorithm is used to predict the jet noise in the static state.This paper mainly considers the influence factors such as frequency,engine power,the distance between the noise source and the measuring point,the direction of the noise.Geting the jet noise under static state,and then transform the forecasting method into the flight state.In the conversion process,we need to take into account the related mapping factors such as atmospheric absorption and ground reflection that affect the mapping,the sound pressure level of the jet noise at each measuring point on the flight path is calculated,further calculated to obtain the total sound pressure level,the perception noise level and the weighted sound pressure level at each position,and finally an effective perceptual noise level for evaluating the influence of noise on the people is finally calculated.Using Boeing 777 aircraft approach noise prediction to test the method described in this paper.The program for noise calculation is further developed through related software.Parameters such as environment and structure can be input into the parameter input module.In the data preprocessing module,The other parameters are further calculated from the basic parameters.and noise prediction module respectively predict the inflow,outflow and mixed flow noise,correction module mainly corrected desired conversion process such as sound attenuation,and finally obtains the jet noise during the approach through the output module,and further analyzes the noise value to get the jet noise has the frequency trend and the direction trend.The full text is based on jet noise prediction for algorithm verification,program development,and correction conversion.After predicting the noise value of each component,the noise of the entire machine is calculated by the relevant algorithm.It is verified that the predicted result is within a reasonable range,The method can provide ideas for noise prediction of other components,after predicting the noise value of each component,the whole machine noise can be calculated through relevant algorithm,which provides a basis for the validation of noise airworthiness.Predicted noise values can also provide reference for noise reduction design of aircraft components.