Valid Regions of Formulas of Sound Speed in Bubbly Liquids
Yu-Ning Zhang**, Zhong-Yu Guo, Yu-Hang Gao, Xiao-Ze Du
Key Laboratory of Condition Monitoring and Control for Power Plant Equipment (Ministry of Education), North China Electric Power University, Beijing 102206
Abstract：There are numerous formulae relating to the predictions of sound wave in the cavitating and bubbly flows. However, the valid regions of those formulae are rather unclear from the view point of physics. In this work, the validity of the existing formulae is discussed in terms of three regions by employing the analysis of three typical lengths involved (viscous length, thermal diffusion length and bubble radius). In our discussions, viscosity and thermal diffusion are both considered together with the effects of relative motion between bubbles and liquids. The importance of relative motion and thermal diffusion are quantitatively discussed in a wide range of parameter zones (including bubble radius and acoustic frequency). The results show that for large bubbles, the effects of relative motion will be prominent in a wide region.
2017, Vol. 34 
