Example14 Cooling by Fan

General

  • A fan is placed inside the case to cool the heat source.
     

  • The fan pressure and the flow rate are determined by the pressure loss. The operating point of the fan can be output as well.

  • The monitoring values are used for convergence judgment.

  • The temperature distribution and the heat flux vectors are solved.

  • The results can be viewed by the simultaneous display of temperature contours and streamlines.
     

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

 

Analysis Space

Item

Setting

Analysis Space

3D

Model Unit

m

 

Analysis Condition

Item

Setting

Solver

Fluid analysis [Bernoulli]

Thermal analysis [Watt]

Analysis Type

Fluid analysis: Steady-state analysis

Thermal analysis: Steady-state analysis

Detailed Setting

Convergence judgment by monitoring value

Enable

 

 

Tab

Monitoring Quantity

Setting

Monitoring

Temperature

Monitoring Domain: select Body Attribute
Monitoring Value: select Maximum Value
Body Attribute Name: select All Body Attributes

Volumetric Flow Rate

Monitoring Domain: select Body Attribute
Body Attribute Name: select Fan

 

Model

The heat dissipation of the heat source in the case is calculated.

A fan and a vent are set on the case.

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

3/Solid

Source

Si

5/Solid

Case

001_Al *

6/Solid

Fan

000_Air *

7/Solid

Air

000_Air *

* Available from the material DB

 

 

Body Attribute Name

Tab

Setting

Fan

Fluid

Inflow and outflow faces are set to the circular model

 

Fluid body type: Specify flow

Inlet/outlet type: Fan

P-Q characteristics

Number

Volumetric Flow Rate (Q)[m3/s]

Differential Pressure (P)[Pa]

1

0

30

2

0.2

0

 

 

Boundary Condition

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Setting

Outer Boundary Condition

Fluid-Thermal

Inlet/Outlet

Natural inflow/outflow

Inflow temperature: Use ambient temperature (25[deg])

 

Results

The calculation was terminated by the monitoring values for convergence judgment before the residual converges.

 

Below are the transitions of the flow rate of the fan and the maximum temperatures of each body attribute that are registered as the monitoring values in advance.

(Displayable by clicking Check Convergence Status button in the dialog box after the analysis finishes)

Since the results are almost constant, it can be interpreted to be acceptable to terminate the calculation before the residual converges.

 

 

The figure below shows the streamlines and the contours of temperature distribution of the heat source at the same time. The contour field of the case is hidden.

The air flows into the case from the vent and flows out through the fan.

 

 

The operating point of the fan can be viewed in the result table.

 

By displaying on the graph, the operating point can be located on the P-Q characteristic.