EFFECT OF AMPLIFICATION OF SHOCK WAVES IN BULK MEDIA

It is well known that shock waves in sandy environments are absorbed, i.e. as they pass through the bulk medium, their amplitude decreases. In shock tubes, as a rule, the results of the impact of shock wave pulses on an object are studied, leading to a change in the shape and amplitude of the pulse that characterizes the medium. In a shock tube equipped with a section of bulk media, the wave is repeatedly reflected from the surfaces of the porous medium under study and the upper end of the tube. The amplitude and shape of the reflected wave differs insignificantly from the main pulse. At the same time, the amplitude of the re-reflected wave propagating in the sand immediately after exposure (13 ms) to the main pulse increases more than three times compared to the amplitude of the main pulse at this depth. Compared to its value at the sand surface, the amplitude in the sand thickness becomes almost twice as high. The maximum amplification of the amplitude of a reflected wave in a bulk medium increases with increasing layer through which the pulse passes to a certain depth, and then begins to decrease.

sand fill, shock tube, shock wave pulse, main pulse, probing pulse, pressure peak, bulk medium layer