Nonlinear effects in the propagation and measurement of blast noise

摘要

It is well known that nonlinearity affects the propagation of blasts. For example, the high levelsof blast noise lead to nonlinear steepening. Mach stem formation and harmonic generationleading to an enhanced high frequency content are other established phenomena. However, othernonlinear aspects of blast wave propagation, such as pressure amplification on a microphonediaphragm are less well known. Other commonly overlooked effects include nonlinear waveinteraction with finite impedance grounds and the influence of nonlinearity on blast rise times.The goal of this paper is to elucidate some of these lesser known nonlinear effects. In additionsome suggestions are made for future field tests that will help to clarify the role of thesenonlinear propagation phenomena.