Session 3aNS: Noise 3aNS6. Prediction of nonlinear propagation of noise from a solid rocket motor

​ *Corresponding author's address: Physics and Astronomy, Brigham Young University, N283 ESC, Provo, UT 84602, [email protected] Generalized Burgers equation-based predictions of noise propagation are compared with measurements from a static, horizontally-fired solid rocket motor over a range of 76-1220 m during an 80 s burn time. The modeling suggests the nature of the geometric spreading between 76 and 305 m varies from cylindrical at low-frequencies to spherical at high frequencies. The predicted waveforms and high-frequency spectral slopes associated with significant shock content are in agreement with properties of the measured noise. At 1220 m, the relatively simple nonlinear model again approximates the measured spectrum despite the complexities of the measurement environment and atmospheric propagation.