Mixer(MRF)
Download mesh
Download simulation
Introduction
This example is an MRF simulation of a mixer with a simple geometry. The MRF model enables steady-state calculations and allows the use of rotational periodic conditions based on one impeller blade, which can significantly reduce the computational cost.
The simulation conditions are as follows
- solver : buoyantSimpleNFoam
- turbulence model : $Standard$ $k-epsilon$ model
- density : 1000 $kg/m^3$
- viscosity : 0.001 $kg/ms$
- rotation velocity : 100 RPM
Start BaramFlow and load mesh
Run the program and select [New Case] from the launcher. In the launcher, select [Pressure-based] for [Solver Type] and [None] for [Multiphase Model].

Use the given polyMesh folder. In the top tab, click [File]-[Load Mesh]-[OpenFOAM] in that order and select the polyMesh folder.
General
For this example, we’ll use default conditions.
Models
For this example, we’ll use default conditions.
Materials
Change the Name to water and enter a Density of 1000 and a viscosity of 0.001.
Cell zone Conditions
Select [Multiple Reference Frame, MRF] at [Cell Zone Conditions] and set values as follows
- Multiple Reference Frame
- Rotating Speed : 100(RPM)
- Rotation-Axis Origin : (0 0 0)
- Rotation-Axis Direction : (0 0 1)
- Static Boundary : periodic1, periodic2

Boundary Conditions
Each boundary condition is set as follows
- periodic1, periodic2 : Interface – Rotational Periodic
- periodic1 : Change to Rotational Periodic, then select periodic2 as [Coupled Boundary]
- Set [Rotation-Axis Origin] as (0 0 0), [Rotation-Axis Direction] as (0 0 1)

- impeller, impeller_slave : Thermo-Coupled Wall
- impeller : Change to Thermo-Coupled Wall, then, select impeller_slave as [Coupled Boundary]
- wall, hub, hub_rot : Wall
- Velocity Condition : noSlip
- top : symmetry
Numerical Conditions
For this example, we’ll use default conditions.
Initialization
For this example, we’ll use default conditions.
Click the Initialize button at the bottom. Then click the [File]-[Save] menu to save the case file.
Run
Change [Number of Iteration] as 3000 and click [Start Calculation] button.
