Pressure impulse vs. peak pressure of shock wave in microchannel: which affects microjet velocity / cavitation onset?
2017
The development of needle-free injection systems utilizing high-speed microjets is of great importance to world healthcare. It is thus crucial to control the microjets, which are often induced by underwater shock waves. In this contribution from fluid-mechanics point of view, we experimentally investigate the effect of a shock wave on the velocity of a free surface (microjet) and underwater cavitation onset in a microchannel, focusing on the pressure impulse and peak pressure of the shock wave. The shock wave used had a non-spherically-symmetric peak pressure distribution and a spherically symmetric pressure impulse distribution [Tagawa et al., J. Fluid Mech., 2016, 808, 5-18]. First, we investigate the effect of the shock wave on the jet velocity by installing a narrow tube and a hydrophone in different configurations in a large water tank, and measuring the shock wave pressure and the jet velocity simultaneously. The results suggest that the jet velocity depends only on the pressure impulse of the shock wave. We then investigate the effect of the shock wave on the cavitation onset by taking measurements in an L-shaped microchannel. The results suggest that the probability of cavitation onset depends only on the peak pressure of the shock wave. In addition, the jet velocity varies according to the presence or absence of cavitation. The above findings provide new insights for advancing a control method for high-speed microjets.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
0
Citations
NaN
KQI