The Study Of The Correlation Of Two Types Of Tire Noise Test Methods

This paper mainly studies how to predict the tire pass by noise results of the car coastdown test in the outdoor by its indoor test datas,and analysis the feasibility of conversion between the two methods,the directivity of acoustic source,and establish a simplified mathematical model of the sound source,the estimation theory and formula for output,as follows:1st.Study on a single tire indoor test methods,establish a method for the semi anechoic room tire noise test,through this method,correlation analysis of indoor test datum,to determine the feasibility of the tire test data conversion between indoor and outdoor.2nd.Study the directivity of tire noise source,understand the directivity of tire source,provide direction for data transformation theory between two methods,and provide basis for microphone placement.3rd.Set up a mathematical model for the estimation theory,and the formula of the estimation calculation.4th.Predict the tire pass by noise,using the tire indoor(a semi anechoic chamber)noise measurement datas,as the input of tire noise point source for the vehicle pass by testing,According to the the distance attenuation calculation,and The superposition calculation for the two microphones datum,and the pass by noise prediction results are obtained.5th.Compare the prediction results with the pass by noise results,and determine the difference between the prediction data between the different test fields.