Abstract:
The problem of sonic boom is one of key problems to be solved in the development of supersonic civil aircraft. In-flight flow-field signature measurements is the most direct method to study the sonic boom characteristics of supersonic aircraft. It can provide truly credible verification data for the sonic boom prediction method and low sonic boom design technology, which is of great significance to the design of a new generation of low-sonic boom supersonic civil aircraft. Technologies related to sonic boom flight test track planning, ground-air integrated large-scale array sonic boom measurement are developed by Chinese Aeronautical Establishment and Chinese Flight Test Establishment. The first domestic special in-flight sonic boom test program of supersonic aircraft was carried out, collecting multiple sets of sonic boom measured data under real atmospheric conditions, which confirmed the rationality of the in-flight test plan. The sonic boom waveform measured on track has significant correlation. The relative error of the sonic boom signal bow shock peak is about 18%, which of the tail shock peak is about 8%. The duration of the sonic boom signature is around 0.1 s. The far-field boom measured data and numerical prediction results are compared and analyzed. When the aircraft flies over the measurement array, the basic shape of the sonic boom signatures obtained is consistent, and the duration is relatively close. The relative error between the peak values of the bow shock and the wing leading edge shock is less than 5%. However, due to factors such as the simplification of the simulation model and the nonlinear cumulative effect of the long-distance propagation of the sonic boom, the predicted sonic boom signals have certain differences in local characteristics, which requires further research on the prediction method of far-field sonic-boom in real atmospheric environment.