mech-ht 15.0 ws05 solenoid

1 2013 ANSYS, Inc. September 15, 2014 ANSYS Confidential

15.0 Release

Workshop 5:

Solenoid

ANSYS Mechanical Heat Transfer


Problem Description

This model represents an electrical solenoid composed of several different materials. An iron core is surrounded by copper, separated by a plastic insulator. The coil is

supported on a steel bracket. The iron core generates heat., while the surface of the copper experiences natural

convection. One face of the bracket is constrained to a fixed temperature.

Goal: Determine the temperature distribution in the solenoid assuming the device has reached a steady state.


Units Setup

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

Choose to Display Values in Project Units.


Model Setup 1. From the Workbench project page toolbox, select

a Steady State Thermal analysis system.

2. Double click the Engineering Data to create and enter Engineering Data tab in the project page

3. Toggle on the Engineering Data Sources and from the General Materials library add:

Copper Alloy Gray Cast Iron Polyethylene


Model Setup

4. Right click the Geometry cell and import geometry Solenoid_WS5.stp.

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

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

BODY MATERIAL

Coil Copper Alloy

Core Gray Cast Iron

Insulator Polyethylene

Bracket Structural Steel


Preprocessing

7. Highlight the Mesh branch and expand the Sizing section in the details.

8. Change the Relevance Center to Medium.

9. Highlight the mesh branch, RMB > Generate.


Preprocessing

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.


Preprocessing 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/(mm2 x C) Ambient Temperature = 25 C


Preprocessing 18. Select one side face on the bracket part.

19. RMB > Insert > Temperature.

20. Enter a magnitude of 25 C.

Since weve assumed a linear steady state condition all analysis settings will remain in their default configuration.

21. Solve


Postprocessing

Before reviewing results lets first verify that we have a steady state condition as expected.

The applied heat generation was 0.001 W/mm3 to the core.

By inspecting the properties of the core we can see the volume of the core is 44,698 mm3.

The resulting heat dissipated through the temperature boundary and the convection should be: 0.001 W/mm3 x 44698 mm3 = 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


Postprocessing

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

Convection reaction = -11.862 W Temperature reaction = -32.835 W RT + RC = - 44.697 W Load sould be 44.698W

Note: your results may vary slightly from those shown due to meshing variations.


Postprocessing 25. Insert a Temperature result to the Solution branch.

26. Evaluate All Results

Due to the extremes in the model, local variation is difficult to discern

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

With elements shown


Postprocessing 28. Highlight the solution branch and insert Total Heat Flux.

Although contours for heat flux can be displayed, a vector plot is instructive for directional quantities.

29. Activate the vector plot mode.

30. Use the vector controls to adjust the display (e.g. vector length, density, etc.).


Postprocessing Next we would like to see how the temperature varies along a

path within 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

33. Highlight the Model branch and insert Construction Geometry.

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


Postprocessing

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.


Postprocessing

Evaluate All Results.

Contour displayed along path Graph shows temperature variation along path

mech-ht 15.0 ws05 solenoid

Documents

ansys confidential model

iron core

steady state thermal

resulting heat

applied heat generation

internal heat generation

linear steady state

steel bracket