2017 Volume 30 Issue 5 Pages 519-527
Gas-liquid flows driven by rotating rigid objects are numerically studied. The Volume-Of-Fluid (VOF) and Boundary Data Immersion (BDI) methods are employed to treat the gas-liquid and fluid-rigid interfaces, respectively. The basic equations are solved by means of finite difference method using a regular Cartesian mesh. Two types of systems are considered: one is a simple geometry composed of cylindrical disk and container to exhibit the validity of the numerical approach, and the other is a complex geometry including holes and/or caves to clarify the relevance to the two-phase mixing and forcing. Numerical simulations are performed for various angular speeds Ω and compared with the experiments. The simulated results demonstrate the capability in capturing the gas-liquid distribution, the torque on the disk and the velocity distribution obtained by Particle Image Velocimetry (PIV). For the complex system, the torque at low Ω is dependent mainly on Ω irrespective of the presence of the holes/caves, while beyond a certain Ω, the considerable jetting flow structure forms due to the presence of the holes on the disk, and therefore the geometry effect on the torque becomes significant.
