Mech-HT 120 WS04 Solenoid

Workshop 4

Solenoid

WS 4-1ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved.

August 2009Inventory #002667

ANSYS Mechanical Heat Transfer

Workshop 4 - Solenoid

Training ManualProblem Description• This model represents an electrical solenoid composed of se veral different

materials.• An iron core is surrounded by copper, separated by a plastic i nsulator. The

coil is supported on a steel bracket.• The iron core is generating heat at a rate of 0.001 W/mm 2, while the surface of

the copper experiences natural convection. One face of the b racket isconstrained to a fixed temperature.



• Goal: determine the temperature distribution in the soleno id assuming thedevice has reached a steady state.


Training ManualUnits Setup

• Open Workbench and specify the unit system (Metric, kg, mm, s, ºC, mA, N, mV).

• Choose to “Display Values in Project Units”.




Training ManualModel Setup

1. From the Workbench project page toolbox, select a Steady State Thermal analysis system.



2. Double click the Engineering Data

3. From the “General Materials library add:• Copper Alloy• Gray Cast Iron• Polyethylene


Training ManualModel Setup

4. Right click the Geometry cell and import geometry “Solenoid_WS4.x_t”.

5. Double click the Model cell to open the Mechanical application.



6. From the Geometry branch assign materials for each part as shown earlier .

• Note: this model was created in DesignModeler as a multi-body part. The result is a continuous mesh throughout the assembly. There are no contact regions defined, or necessary.


Training ManualPreprocessing

7. Highlight the Mesh branch, RMB and Generate Mesh.– Due to the nature of this

geometry the default mesh results in reasonably size/shaped elements for all but the bracket part.



8. Activate the body select filter and select the bracket part.

9. From the Mesh Control menu choose “Sizing”.

10. Input an element size of 2mm.

11.Generate the mesh again.



12.Highlight the “Steady State Thermal” branch and select the “core” part.

13.RMB > Insert > Internal Heat Generation.



14. In the details for the heat generation input a magnitude of 0.001 W/mm3.



15.Activate face selection and select the 8 exterior and 3 top surfaces of the solenoid (11 total).

16.RMB > Insert > Convection.



17. In the details enter the convection properties:– Film Coefficient = 5e -5 W/(mm 2 x ºC)– Ambient Temperature = 25 ºC



18.Select one side face on the bracket part.

19.RMB > Insert > Temperature.20.Enter a magnitude of 25 ºC.



• Since we’ve assumed a linear steady state condition all analysis settings will remain in their default configuration.

21.Solve


Training ManualPostprocessing

• Before reviewing results let’s first verify that we have a steady state condition as expected.

• The applied heat generation was 0.001 W/mm 3

to the core.• By inspecting the properties of the core we can

see the volume of the core is 44,698 mm 3.– The resulting heat dissipated through the

temperature boundary and the convection should



temperature boundary and the convection should be: 0.001 W/mm 3 x 44698 mm 3 = 44.698 W.

22.Using the control key, highlight both the convection and temperature boundary conditions.

23.Drag and drop the loads onto the Solution branch.– The result is 2 reaction probes are automatically

inserted.

24.RMB > Evaluate All Results



• The details for each of the reaction probes show we have an energy balance:

– Convection reaction = -9.8475 W– Temperature reaction = -34.85 W– RT + RC = - 44.6975 W– Recall heat input from previous page.





25. Insert a Temperature result to the Solution branch.

26.Evaluate All Results– Due to the extremes in the model, little variation

in temperature can be seen in this plot.

27.Activate body selection and select only the insulator part, then repeat the above steps.



Full ModelScoped Model



28.Highlight the solution branch and insert Total Heat Flux.– Although contours for heat flux can be displayed, o ften

a vector plot is instructive for directional quanti ties.

29.Activate the vector plot mode.30.Use the vector controls to adjust the display (e.g.

vector length, density, etc.).





• Next we would like to see how the temperature varies across a section of the solenoid.

• Begin by adding 2 local coordinate systems.31.Change “Define by” to “Global Coordinates”.32.Use the following origin locations for each:

– CS 1: X , Y, Z = 23, 50, 4– CS 2: X, Y, Z = 23, 50, 38

Example



33.Highlight the Model branch and insert “Construction Geometry”.

34.From the construction geometry branch RMB > Insert > Path”.

Example



35. In the details for the Path, switch the starting and ending locations to the local coordinate systems just created.– Note, in the example shown the coordinate

systems were renamed to “start” and “end”.



36. Insert a new temperature result in the Solution.

37.Switch to “Path” as the Scoping Method.

38.Choose the path in the details.



• Evaluate All Results.



Contour displayed along path Graph shows temperature variation along path

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Mech-HT 120 WS04 Solenoid