Abstract |
Interaction of Radial and Forward
Pulses of Cavitation Bubbles
I.Margulis (Department of
Sonochemistry, N.N. Andreyev Acoustics Institute, Moscow, Russia)
e-mail:
margulis@akin.ru
In
the work we consider main reasons of bubble's forward motion and influence of
forward motion on bubble dynamics. We obtained a new system of equations that
described bubble.s radial and forward motion. Calculations were carried out for
two types of acoustic field: standing and progressive sinusoidal sound
waves. At fast collapse the effective
transmitting of radial energy into forward one takes place. Forward motion
damps adiabatic collapse considerably, usually forward motion decreases Tmax in
4 times (to 2800 K) and maximum of r in 4 times (to 140 m.s-1). So, if heat
exchange, lose of sphericity, interaction with other bubbles and flows of
liquid are taken into consideration additionally, in the field of progressive
sound waves Tmax <= 1000 K. While one observes smooth forward motion of
cavitation bubbles, they jump for every fast collapse and stay immovably during
remaining time. Maximum of u (at fast collapse) reaches several hundreds of
m.s-1. A mean per a period u is calculated to be 1.5 m.s-1 corresponds to
experimental data.
Section
: 11