The propagation of N waves through turbulence : an experimental study

a model experiment to study the effect of atmospheric turbulence on sonic booms is reported. The model sonic booms are N waves produced by electric sparks, and the model turbulence is created by a plane jet. The important parameters are the waveform, peak pressure, and rise time because they determine the annoyance caused by sonic booms. Our experiment was designed so that the scale factor (approximately 10-4) relating the model turbulence to atmospheric turbulence was the same as that relating the model N waves to sonic booms. Results are reported for plane waves and are as follows. 1. The model experiment successfully simulates sonic boom propagation through the atmosphere. 2. Passage through turbulence almost always causes rise time to increase. 3. Average rise time is always increased by turbulence. 4. Average peak pressure is always decreased by turbulence