|
Home / Examples / Fluid Analysis [Bernoulli] / Example18: Flow Around Spinning Top
Example18: Flow Around Spinning Top
General
-
With the moving wall condition, the flow around the spinning top is calculated.
-
Velocity distribution, velocity vectors, streamlines, and wall torque are solved.
-
Unless specified in the list below, the default conditions are applied.
-
Obtain this session's project file. (Right-click and choose 'Save link as')
-
Results will vary depending on Femtet version and the PC environment.
Analysis Conditions
|
Item |
Settings |
|
Analysis Space |
3D |
|
Unit |
mm |
|
Item |
Tab |
Settings |
|
Solver |
Solver Selection |
Fluid Analysis [Bernoulli] |
|
Analysis Type |
Fluid Analysis |
Transient Analysis |
|
Flow Type |
Fluid Analysis |
Select External Flow. |
|
Meshing Setup |
Mesh |
General Mesh Size: 20 [mm] |
Model
Body Attributes and Materials
|
Body Number/Type |
Body Attribute Name |
Material Name |
|
5/Solid |
Top |
002_Polycarbonate(PC) * |
|
6/Solid |
Air |
000_Air * |
* Available from the material DB
Moving Wall is set in the body attribute of Top.
|
Body Attribute Name |
Tab Name |
Settings |
|
Top |
Solid |
Solid Wall Type: Moving Wall Wall Motion: Rotation Vector of Axis: 0.0, 0.0, 1.0 Coordinate of Axis: 0.0, 0.0, 0.0 Angular Velocity: -1000 [r/min] |
Boundary Conditions
|
Boundary Condition Name/Topology |
Tab |
Boundary Condition Type |
Settings |
|
Ground/Face |
Fluid |
Solid Wall |
Since the flow type is set to [External Flow], the inlet/outlet type of the outer boundary condition is automatically set to natural inflow/outflow.
Results
The vectors of the flow velocity distribution are shown below.
The vectors in the XZ plane at Y=0 are shown below.
Two whirlpools can be observed under the spinning top as below.
The value of the wall torque is in the table.
The wall torque is 1.314e-4 [N m].
The decrease in velocity due to the air resistance can be observed.