PSI - Issue 33

Irina A. Bannikova et al. / Procedia Structural Integrity 33 (2021) 1146–1151 Author name / Structural Integrity Procedia 00 (2019) 000–000

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(homogeneous nucleation) during compression, caused by the inertial expansion of bubbles when changing the sign pressure.

Fig. 1. Velocities of the free surface in distilled water, obtained at different distances from the place of EEW initiation.

Fig. 2 shows the profiles of the free surface velocity V Sf (t) obtained in surfactant solutions. For the profiles of surfactant solutions, large amplitudes of the velocity V 0 are characteristic at small distances from the place of the EEW (X = 35 mm) and almost the same amplitudes of the velocity V 0 , not exceeding 20 m/s, for others. In Guar (see Fig. 2, a), the dotted lines show the extrapolation of the free surface velocity in the absence of cavitation. Both in Guar (Fig. 2, a, X = 45 mm) and in Surfogel (Fig. 2, b) on the rarefaction wave profile, before the spall impulses, there are several stages of pore growth with different growth rates. Subsequent reverberations are associated with the passage of waves between the spall surface (the surface of the bubble or cavity) and the surface of the sensor membrane.

Fig. 2. Free surface velocity profiles obtained at different distances from the place of EEW in surfactant solutions: a - Guar; b - Surfogel.