Simple Agitated Tank¶
Model Set-up
Start M-Star Build via Windows Start Menu
Build -> Define Outer Geometry
Choose: Vertical Cylinder
Click on the BoundingGeometry component in the Model Listing
Specify tank diameter: 1.0 m
Specify tank side wall height: 1.0 m
Specify bottom shape: Dish
Specify floor depth: 0.1 m
Specify baffle count: 4
Specify baffle width: 0.05 m
Specify fluid height: 1 m
Specify head space: 0. m
Build -> Define Moving Geometry
Choose: Pitch Blade Impeller
Specify impeller diameter: 0.35 m
Specify shaft length: 0 m
Specify blade angle: 45 degrees
Specify impeller speed: 60 RPM
Specify impeller start-up ramp: 0 s
The tank side wall height plus the tank floor depth gives the total tank height
The impeller mount point and orientation can be tuned via Ref. Point and Ref. Axis
Multiple impellers with unique positions, orientations, and rotation axes can be defined
Setting either the shaft diameter of shaft length to zero eliminates the shaft
The ramp evolves the impeller from rest to the set speed via a quarter sine wave
Select the Simulation Component
Specify Resolution on Reference Length: 150
Specify runtime: 60 s
Specify CheckPointInterval: 10 s
Specify data output: 0.005 s
Specify slice output: 0.05 s
Specify volume output: 1 s
The simulation lattice is uniform with a resolution defined by Resolution on Reference Length
The timestep is calculated from the resolution, impeller speed, and Courant number
Data output describes the output frequency of forces, torques, and blending
Slice/volume output describes the output frequency of visualization files.
The CheckPointInterval describes the print frequency of simulation restart files.
Model Processing
Solve -> Run Solver
Choose an appropriate output location
Specify an appropriate number of cores
The solver may produce several GB of data, make sure ample disc space is available
Terminate the simulation at any time by closing the black command prompt window
File -> Save As
Save your model with an appropriate name as a .3dm file
Visualzation and post-processing
Start M-Star Post via Windows Start Menu
Browse to your output directory in Windows
Open the slices.txt in ParaView
Press the MStarPost button.
Click on the Impeller0 tab
Examine the time-evolution of the force on the impeller, Fx, Fy,Fz
Examine the time-evolution of Np, the impeller power number.
Examine the time-evolution of Nq_side, Nq_top, and Nq_bottom the three pumping numbers
The Fy force should be greater in magnitude than Fx and Fz, due to axial thrust
The initial Np should be high, as the impeller must accelerate an initially quiescent fluid.
Negative pumping numbers imply flow into the swept volume.
Click on the 3D View tab
Press the green play button to animate the sequence
Change the view from 2D to 3D by pressing the 3D button below the 3D View tab heading:
Hold down the right mouse button to zoom
Hold down the left mouse button to rotate
Hold down the center mouse button to pan
Zoom to fit by clicking the zoom icons:
Frame sequences or pre-compiled movies can be generated from File->Save Animation.
Updated data can be imported by right clicking files in the browser and selecting Reload Files