Mitigation of gun blast noise by surface impedance design

摘要

Surface impedance is designed to mitigate gun blast noise with high energy and low frequencies.By corrugating the ground surface with trenches of critical depths, artificially soft surface can begenerated at the openings of those trenches inside the ground. If such trenches are enough, thestructure can effectively mitigate the propagation of acoustic wave along the ground bydestructive interference. Compared with the use of ground shelters, the approach may becheaper, safer and space efficient. To examine the effectiveness of the model, we develop anefficient numerical solver to solve acoustic wave scattering by the ground. The ground istruncated circularly with a large radius and the trenches are concentrically shaped so that we cantreat it as a body of revolution (BOR). Numerical simulations show that the scheme caneffectively reduce the sound level at the far zone by selecting appropriate design parameters.