Mech_HT_18.0_WS02.1_Heating_Coil analysis.pdf

heating coil thermal analysis

1. 1 © 2017 ANSYS, Inc. May 10, 2017
Workshop 02.1: Heating Coil
18.0 Release
ANSYS Mechanical Heat Transfer

2. 2 © 2017 ANSYS, Inc. May 10, 2017
Problem Description
•This model consists of a tungsten coil that is generating heat due to electrical resistance.
The load is simulated using internal heat generation. We further assume the coil
operates in a vacuum so the only heat transfer mechanism is radiation.

3. 3 © 2017 ANSYS, Inc. May 10, 2017
Open Workbench and specify the unit system:
Metric (kg, mm, s, ºC, mA, N, mV)
Choose to “Display Values in Project Units”
Units Setup

4. 4 © 2017 ANSYS, Inc. May 10, 2017
Model Setup
1.From the Workbench project page
toolbox, select a Steady State
Thermal analysis system.
2.Double click the Engineering Data
cell.
3.Under the “Engineering Data” tab
and in the field labeled “Click here to
add a new material”, enter:
•Tungsten

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4.From the Engineering Data toolbox
drag and drop “Isotropic Thermal
Conductivity” onto the “Tungsten”
cell.
5.Enter 0.118 W/mm.ºCin the “Isotropic
Thermal Conductivity field.
6.Return to Project by clicking on the
Project Tab.
7.Right click the Geometry cell and
import geometry
“Heating_Coil_WS02.1.stp”.
Model Setup

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8.Double click the Model cell to
open the Mechanical
application.
9.Expand the Geometry branch
and assign the material
“Tungsten” to the part.
Model Setup

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10.Change the selection filter to “body”
selection and Select the “Steady-State
Thermal branch in the model tree.
11.In the graphics window, “RMB > Select All”.
12.RMB > Insert > Internal Heat Generation.
•Enter a magnitude = 0.02 W/mm
3
Preprocessing

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13.Change the selection filter to “surface” selection.
14.Select one exterior surface (not one of the ends of the coil).
15.Choose to “Extend to Limits”.
•The status bar should indicate 3 faces selected.
16.RMB > Insert > Radiation
17.In the radiation details enter:
•Emissivity = 0.25
•Ambient Temperature = 30 ºC
18.Solve
Preprocessing

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19.While the solution proceeds (or after it’s complete) review the solution information.
Change the solution output to “Heat Convergence”.
•Note although this was a steady state solution, iteration and substepsare required because it is
nonlinear. The radiation boundary condition renders the solution nonlinear, as the convergence
behavior shows. We will discuss nonlinear solution options later in the training course.
Solution

10. 10 © 2017 ANSYS, Inc. May 10, 2017
Checking for a steady state condition we note:
•Volume = 15978 mm
3
•Heat generation = 0.02 W/mm
3
•Total heat generation = 318.5W
20.Drag and drop the “Radiation” boundary condition onto the Solution
branch.
•This creates a reaction probe.
21.Evaluate results.
•Note the calculated reaction, 324.9 W, is within ~3% of the actual
heat generation above.
•We will detail the conditions and controls that affect nonlinear accuracy later.
Postprocessing

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22.Add thermal results and evaluate.
•Scoping to individual surfaces can allow more detailed results to be viewed.
Note: mesh variations may cause differences between your
results and those shown here.
Postprocessing