A hybrid method for the simulation of Reynolds-averaged turbulent flows in axial flow impeller driven mixing vessels is described. The time-mean flow in the impeller region is modelled using blade element theory, while the flow in the remainder of the vessel is simulated using a second-order finite-volume Reynolds-averaged numerical scheme. The two models are iteratively coupled through boundary conditions and computation of the power dissipated in the mixing vessel. This approach is computationally cheaper than alternatives that require the details of the flow in the impeller region to be resolved. Simulation results are compared to a detailed laser-Doppler examination of the flow in a laboratory vessel, and it is shown that the average absolute difference between simulated and measured velocities was of the order of 1% of the impeller tip speed. In addition the power consumption was predicted to two-figure accuracy.
- Blade element