NUMERICAL SIMULATION OF BUBBLE GROWTH AND COLLAPSE IN POOL BOILING: EFFECT OF BUBBLE MOTION

In the present work, we numerically solve the energy equation of the surrounding liquid for spatio-temporal variation of temperature in a spherical geometry, which includes the phase motions. The motion of a bubble is considered to attain a rise velocity, assuming a bubble of a finite size initially placed in the pool of liquid, which is allowed to grow and collapse. The radial velocity component is obtained from the streamlines of the surrounding liquid based on a potential flow along with an additional term due to the velocity of bubble wall; the approach velocity is approximated to the rise velocity. The energy equation at the vapour-liquid interface computes the rate of bubble growth and collapse, and the Rayleigh-Plesset equation the vapour pressure inside the bubble. The numerical simulation shows a considerable improvement by our method over the semi-analytical method while validating with the experimental and theoretical works on bubble growth with the phase motion. The method also simulates the bubble collapse without phase motion with a good accuracy; the semi-analytical method works much better for the collapse with phase motion.