Study on CFD-PBM turbulence closures based on k-ε and Reynolds stress models for heterogeneous bubble column flows

摘要

Gas-liquid heterogeneous flows in two cylindrical bubble columns are simulated using the computational fluid dynamics-population balance model (CFD-PBM) implemented in the open source CFD package OpenFOAM. The liquid phase turbulence is described by the k-ε model and the Reynolds stress model (RSM). Simulation results are compared with experimental data from the literature. For the bubble column operated at 0.10 m/s, minor difference is found in the predicted profiles when using 10 and 20 bubble classes. With the Rampure drag coefficient, Tomiyama lift coefficient and bubble-induced turbulence (BIT), the gas holdup is well predicted by both k-ε model and RSM. For the bubble column operated at 0.12 m/s, good agreement with experimental data is obtained when the k-ε BIT model works with the Tsuchiya drag coefficient and Tomiyama lift coefficient. The RSM with BIT also gives reasonable prediction when using the combination of Tsuchiya drag coefficient and Tomiyama lift coefficient.