The effect of the VOF-CSF static contact angle boundary condition on the dynamics of sliding and bouncing ellipsoidal bubbles

作者：Senthilkumar S^*; Delaure Y M C; Murray D B; Donnelly B

来源：International Journal of Heat and Fluid Flow, 2011, 32(5): 964-972.

DOI：10.1016/j.ijheatfluidflow.2011.06.008

• Gas-liquid flow
• Sliding bubble
• Volume-of-Fluid
• PLIC method
• SIMPLE algorithm
• Static contact angle

The static contact angle is the only empiricism introduced in a Volume of Fluid-Continuum Surface Force (VOF-CSF) model of bubbly flow. Although it has previously been shown to have a relatively limited effect on the accuracy of velocity and shape predictions in the case of large gas bubbles sliding under inclined walls (e.g. Cook and Behnia, 2001), it may have a more determining influence on the numerical prediction of the dynamics of smaller ellipsoidal bubbles which were shown by Tsao and Koch (1997) to bounce repeatedly when sliding under inclined walls at certain wall inclinations. The present paper reports on the influence of surface tension and the static contact angle on the dynamics of an ellipsoidal air bubble of equivalent diameter D(e) = 3.4 mm. The bubble Eat-vas and Morton numbers are Eo = 1.56 and Mo = 2 x 10(-11) respectively. The computational results are achieved with a Piecewise Linear Construction (PLIC) of the interface and are reviewed with reference to experimental measurements of bubble velocity and interface shape oscillations recorded using a high speed digital camera. Tests are performed at plate inclination angles theta is an element of {10 degrees,20 degrees,30 degrees,45 degrees) to the horizontal and computational models consider three static contact angles theta(c) is an element of {10 degrees,20 degrees,30 degrees). The static contact angle has been found to have a significant effect on the bubble dynamics but to varying degree depending on the plate inclination. It is shown to promote lift off and bouncing when the plate inclination angle reaches 30 degrees in a way that does not necessarily reflect experimental observations.

• 出版日期2011-10