REFLECTION OF UNDERWATER SHOCK WAVES.
Final summary rept.,
NEW HAMPSHIRE UNIV DURHAM
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Recordings were made of pulse shapes generated underwater by No. 6 Electric Blasting caps, and reflected from the plane interface between water and a 20 salt solution wave velocity approx. 5620 ftsec, critical angle with water about 60 degrees, separated by a polyethylene membrane. These records exhibit the general shape and phenomena predicted by the plane wave approximation as a function of angle of incidence --The increase of the reflection coefficient to 100 on approaching the critical angle, the rapid phase shift and inversion of shape, and final complete reversal at grazing incidence. Moreover, the records also show the abrupt arrival of the lateral wave, as well as its shape up to the arrival of the primary pulse. At grazing incidence there appears to be practically complete cancellation of the primary wave by its inverted reflection, for points close to the boundary surface.