Workshop 03.1: Solenoid

1 © 2019 ANSYS, Inc.11

Workshop 03.1: Solenoid

ANSYS Mechanical Heat Transfer

Release 2019 R3

2 © 2019 ANSYS, Inc.22 © 2019 ANSYS, Inc.2

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 issupported on a steel bracket.

• The iron core generates heat, while the surface of the copper experiences naturalconvection. 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.


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

Choose to “Display Values in Project Units”

Units Setup


• From the Workbench project page toolbox, create a Steady-State Thermal analysis system.

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

• Toggle on the Engineering Data Sources

and from the

“General Materials” library add:

• Copper Alloy

• Gray Cast Iron

• Polyethylene

Model Setup


• Return to the Project Schematic

• Right click the Geometry cell and import geometry “Solenoid_WS03.1.stp”.

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

• 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

Model Setup


• Highlight the Mesh branch and expand the “Sizing” section in the details.

• Change the “Element Size” to 1.5 mm.

• Highlight the mesh branch, RMB > Generate Mesh.

Preprocessing


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

• RMB > Insert > Internal Heat Generation.

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

Preprocessing


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

• RMB > Insert > Convection.

• In the details enter the convection properties:‐ Film Coefficient = 5e -5 W/(mm2 x ºC).

‐ Ambient Temperature = 25 ºC.

Preprocessing


• Select one side face on the bracket part as shown.

• RMB > Insert > Temperature.

• Enter a magnitude of 25 ºC.

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

• Solve

Preprocessing


Before reviewing results let’s 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.

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

• Drag and drop the loads onto the Solution branch.‐ The result is 2 reaction probes are automatically inserted.

• RMB > Evaluate All Results

Postprocessing


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

‐ Convection reaction = -11.96 W

‐ Temperature reaction = -32.74 W

‐ RT + RC = - 44.7 W

‐ Load should be 44.698W

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

Postprocessing


• Insert a Temperature result to the Solution branch.

• Evaluate All Results‐ Owing to wide differences in material properties, local variations are difficult to discern

with all bodies selected.

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

Postprocessing


• 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.

• Activate the vector plot mode.

• 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.

• Change “Define by” to “Global Coordinates”.

• Use the following origin locations for each:‐ CS 1 which will be called ‘start’: X , Y, Z = 23, 50, 4

‐ CS 2 which will be called ‘end’: X, Y, Z = 23, 50, 38

• Highlight the Model branch and RMB > insert “Construction Geometry”> Path

Postprocessing


• 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”.

• Insert a new temperature result in the Solution.

• Switch to “Path” as the Scoping Method.

• Choose the path in the details.

Postprocessing


Evaluate All Results.

Contour displayed along path Graph shows temperature variation along path

Postprocessing

Documents

Workshop 03.1: Solenoid