Numerical Analysis of Weak-Shock Attenuation Resulting from Molecular Vibrational Relaxation
The shock wave that forms in the near field of an aircraft flying at supersonic speed weakens due to attenuation while propagating in the atmosphere. The explosive sound of the shock wave, commonly known as a sonic boom, is also called an Nwave because its pressure history is shaped like the letter N. Although the shock front segment for an N-wave located near the aircraft is discontinuous and several times that of the mean free path, its duration increases due to relaxation and reaches finite value during propagation in the air. The rise time, which is the time required for the N-wave to go from atmospheric pressure to its peak overpressure, is often used for evaluating the shock front.
KeywordsFast Fourier Transform Euler Equation Attenuation Effect Vibrational Relaxation Pressure History
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