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arXiv · 1504.06674

On pressure impulse of a laser-induced underwater shock wave

Yoshiyuki Tagawa·Shota Yamamoto·Keisuke Hayasaka·Masaharu Kameda
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Abstract

We experimentally examine a laser-induced underwater shock wave with a special attention to pressure impulse, the time integral of pressure evolution. %total pressure variation associated with the shock wave. Plasma formation, shock-wave expansion, and pressure in water are observed simultaneously using a combined measurement system that obtains high-resolution nanosecond-order image sequences. These detailed measurements reveal a non-spherically-symmetric distribution of pressure peak. In contrast, remarkably, pressure impulse is found to distribute symmetrically for a wide range of experimental parameters even when the shock waves are emitted from an elongated region. The structure is determined to be a collection of multiple spherical shock waves originated from point-like plasmas in the elongated region.

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Yoshiyuki Tagawa, Shota Yamamoto, Keisuke Hayasaka, Masaharu Kameda. 2016-10-01. On pressure impulse of a laser-induced underwater shock wave. https://doi.org/10.1017/jfm.2016.644

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