Home / Examples / Simple Fluid Analysis [Pascal] / Example 1: Air Flow in Cylinder

Example 1: Air Flow in Cylinder

General

• Steady-state analysis is performed for the the air flowing through a cylinder.
   

• The air flow is assumed to be laminar, non-viscous and incompressible.
   

• The distribution of the flow velocities is solved.
   

• Unless specified in the list below, the default conditions will be 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 Space

Item	Settings
Analysis Space	3D
Model Unit	mm

 

Analysis Conditions

Item	Settings
Solver	Simple Fluid Analysis [Pascal]
Analysis Type	Steady-state Analysis
Options	N/A

Model

The fluid (Air) in the cylinder is created as a solid body and defined as "Fluid" in the material property.

The body obstructing the flow is a solid body and defined as "Solid" in the material property.

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
0/Solid	Air	000_Air(*)
1/Solid	Solid	Solid

* Available from the material DB

 

Air is set as below.

Material Property Name	Tab	Settings
Air	Solid/Fluid	State: Fluid

Boundary Conditions

The flow velocity is given at the inlet and the velocity potential is given at the outlet.

The velocity potential is set to 0 [m^2/s], resulting in the output opening.

 

• The details are explained at [Fluid] tab of the boundary condition.
   

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Settings
in/Face	Fluid	Flow Velocity	1 [m/s]
out/Face	Fluid	Velocity Potential	0 [m^2/s]

 

Results

The distribution of the flow velocities is shown below.

The flow velocity is higher in the obstructed area, about twice as large as in the non-obstructed area.