Study on the dynamic behaviors of a near wall ventilated bubble using OpenFOAM

In this paper, ventilated bubble injected into a cross-flow is studied for the cases where the gas is injected from a vertical flat surface. The influences of contact angle, incoming flow direction relative to the gravity and surface tension on the dynamic behaviors of ventilation bubble have been studied numerically using OpenFOAM. For cases with different contact angles, there is a critical contact angle 90. When the contact angle exceeds the critical contact angle, the development of ventilation bubble along the cross-section is obviously promoted. In present studies, due to buoyancy and wall barrier effect, there are mainly two gas leakage modes at the rear of the bubble: spherical bubbles falling off and local gas leaks in the form of elongated bubbles at the rear of the ventilation bubble. Besides, once the surface tension coefficient less than 0.036 N/m the morphology of the bubble has a great change and bubble develops faster along the width direction. In addition, for surface tension coefficient less than 0.036 N/m and contact angle greater than 90 , the effect of the surface tension induced by changing of the fluid characteristics on bubble development is similar to that of contact angle induced by different wall types.