Acoustic Propagation Through Vapor Bubbly Liquid: Why Landau-Lifshitz Were Wrong

Dr Yaotian Fu (host James Schilling), Department of Physics, Washington University, St Louis, Missouri
November 20, 2017 at 4:00 pm
241 Compton
Event Description 

Landau and Lifshitz  predicted a sudden drop in sound speed when the wave passes through a liquid filled with its vapor bubbles; experimentally this was not seen. We argue that Landau/Lifshitz were wrong in neglecting the finite time needed for the vapor/liquid phase transition to take place. If, within half an acoustic cycle, the latent heat of phase transition does not have enough time to be transported from inside the bubbles to the outside, the phase transition is incomplete, and it is as if it never took place. That is why it was not seen experimentally.  An improved theory with this effect taken into account is in agreement with the experiment.

Coffee: 3:45 pm, 241 Compton