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Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
Professional CAD/CAM tools built on Inventor and AutoCAD
Set up a heat transfer simulation, modify the design, and run the simulation again using the new settings.
Type:
Tutorial
Length:
7 min.
Tutorial resources
These downloadable resources will be used to complete this tutorial:
Transcript
00:05
Thermal analyses provide you with insights into energy transfer,
00:09
and are particularly useful when your design has thermal failure, or touch temperature criteria.
00:15
How do you find out if your design exceeds the maximum temperature?
00:19
And what can you do if it does?
00:22
In this lesson, using an LED bulb design,
00:26
we discuss how to set up a heat transfer study to see whether an LED bulb is likely to
00:31
exceed 80 degrees Fahrenheit during operation, given the current design of the heat sink.
00:37
We edit the simulation model
00:39
to remove components that have negligible effect on the simulation,
00:43
we apply temperature loads to the model,
00:46
to represent both the heat generated by the diodes and the heat lost to the environment,
00:51
we check the contacts to ensure the heat is transferred properly through the model,
00:56
we run a thermal analysis and review the results,
00:59
and we edit the design model to improve heat dissipation and reanalyze the study.
01:05
The LED bulb has several components.
01:08
Of particular interest to us in our thermal simulation are
01:11
the 4 diodes that generate heat
01:14
the heat sink that helps to dissipate heat,
01:17
and the glass bulb, which we don't need, and is just adding to the analysis time.
01:25
To analyze the design - switch to the Simulation workspace
01:31
and select Thermal study.
01:34
The visual representation of the model changes to display its material
01:38
and an additional body appears that wasn't visible in the Design workspace.
01:42
This body, which was used to help define the shape of the cooling fins of the heat sink,
01:47
has negligible effect on the results of the study,
01:50
and can be removed, along with the glass bulb, to reduce the analysis time.
01:55
In the Simplify environment, select the body and delete it.
02:00
Then, expand the model components, select the globe, and select Remove.
02:06
from the context menu.
02:08
Click Finish Simplify to return to the Setup tab.
02:11
Now we're ready to check the study setup.
02:14
First we'll review the materials in the model using the Study Materials command.
02:20
Since all these materials are appropriate for this analysis, click Cancel to keep them.
02:25
Next we'll place the loads.
02:28
We'll apply a 25 watt internal heat load to these 4 diodes
02:32
to represent the heat they generate.
02:36
This heat load accounts not only for the diodes, but also for the controllers.
02:46
Finally, we'll apply a convective heat transfer coefficient of 1000 W/m2K
02:53
to represent the heat we need removed from the diodes, via the heat sink
02:57
to the environment, based on the heat load and the design dimensions.
03:02
Click, and drag to the left, to select the surfaces of the heat sink
03:06
then set the convection to 1000, keeping the current units.
03:10
In this study, we'll work in Fahrenheit, so change the temperature units
03:14
to Fahrenheit and set the local ambient temperature to 70.
03:21
In the Display panel, select the Degrees of Freedom view.
03:25
This view shows you the conducting elements in green,
03:28
representing the components to which you've added thermal loads,
03:31
And the insulated elements in red.
03:34
We want the heat to transfer through the entire model
03:37
but this view indicates that heat is not being transferred to the red components.
03:42
For effective heat transfer, the components need to know they're connected.
03:47
We use Automatic Contacts to generate contacts, using the default tolerance
03:52
which updates the assembly to ensure all model components contact each other.
03:57
Once the contacts are made, the entire assembly is seen as conducting.
04:02
Precheck shows there are no issues with the setup, so we can now solve the model.
04:16
When the analysis is complete, the result appear.
04:20
Change the temperature units to Fahrenheit, and notice that the temperature ranges
04:24
from 73 to 93 degrees Fahrenheit, which exceeds our 80 degrees goal.
04:30
We'll need to make some modifications to the heat sink to increase its surface area,
04:35
and thereby improve its ability to remove heat.
04:39
If we move the legend slider, so the minimum temperature reads roughly 80 degrees Fahrenheit,
04:44
we can see where, and how much of the model is above this.
04:49
We could use the Simplify environment to create alternative designs,
04:53
but for this model, we'll switch back to the Design workspace
04:56
and take advantage of parametric modeling.
05:01
The last item in our timeline is a circular pattern for the heat sink fins.
05:06
Double-click on the Circular Pattern and increase the number of fins to 40.
05:12
Then click OK to update the model
05:18
Back in the Simulation workspace, you'll see the previous results are still displayed.
05:23
However, there is a warning that the results are not up-to-date
05:27
and notice that the model still shows only 3 fins on the heat sink.
05:31
We'll return to the Setup tab to update the study settings.
05:36
Edit the Convection load
05:39
and clear the current Face Selection
05:42
Then, reselect the faces that represent all 14 fins
05:51
and the bottom face -
05:55
Check Precheck and fix any issues, then solve the job again.
06:07
When the results appear, notice the temperature range is roughly the same.
06:11
But when you adjust the legend slider to 80, you'll see that the temperature is all internal
06:16
and close to the drivers for the LEDs themselves.
06:20
This gives us the result we are looking for,
06:22
but you can continue to make design changes to improve it further.
06:26
In this lesson, we edited the Simulation model
06:29
to remove components that have negligible effect on the simulation,
06:33
we applied temperature loads to the model to represent the heat loads,
06:38
we checked the contacts to ensure that heat is transferred properly through the model,
06:43
we ran a thermal analysis and reviewed the results,
06:46
and we edited the Design model to improve heat dissipation and then reanalyzed the study.
Video transcript
00:05
Thermal analyses provide you with insights into energy transfer,
00:09
and are particularly useful when your design has thermal failure, or touch temperature criteria.
00:15
How do you find out if your design exceeds the maximum temperature?
00:19
And what can you do if it does?
00:22
In this lesson, using an LED bulb design,
00:26
we discuss how to set up a heat transfer study to see whether an LED bulb is likely to
00:31
exceed 80 degrees Fahrenheit during operation, given the current design of the heat sink.
00:37
We edit the simulation model
00:39
to remove components that have negligible effect on the simulation,
00:43
we apply temperature loads to the model,
00:46
to represent both the heat generated by the diodes and the heat lost to the environment,
00:51
we check the contacts to ensure the heat is transferred properly through the model,
00:56
we run a thermal analysis and review the results,
00:59
and we edit the design model to improve heat dissipation and reanalyze the study.
01:05
The LED bulb has several components.
01:08
Of particular interest to us in our thermal simulation are
01:11
the 4 diodes that generate heat
01:14
the heat sink that helps to dissipate heat,
01:17
and the glass bulb, which we don't need, and is just adding to the analysis time.
01:25
To analyze the design - switch to the Simulation workspace
01:31
and select Thermal study.
01:34
The visual representation of the model changes to display its material
01:38
and an additional body appears that wasn't visible in the Design workspace.
01:42
This body, which was used to help define the shape of the cooling fins of the heat sink,
01:47
has negligible effect on the results of the study,
01:50
and can be removed, along with the glass bulb, to reduce the analysis time.
01:55
In the Simplify environment, select the body and delete it.
02:00
Then, expand the model components, select the globe, and select Remove.
02:06
from the context menu.
02:08
Click Finish Simplify to return to the Setup tab.
02:11
Now we're ready to check the study setup.
02:14
First we'll review the materials in the model using the Study Materials command.
02:20
Since all these materials are appropriate for this analysis, click Cancel to keep them.
02:25
Next we'll place the loads.
02:28
We'll apply a 25 watt internal heat load to these 4 diodes
02:32
to represent the heat they generate.
02:36
This heat load accounts not only for the diodes, but also for the controllers.
02:46
Finally, we'll apply a convective heat transfer coefficient of 1000 W/m2K
02:53
to represent the heat we need removed from the diodes, via the heat sink
02:57
to the environment, based on the heat load and the design dimensions.
03:02
Click, and drag to the left, to select the surfaces of the heat sink
03:06
then set the convection to 1000, keeping the current units.
03:10
In this study, we'll work in Fahrenheit, so change the temperature units
03:14
to Fahrenheit and set the local ambient temperature to 70.
03:21
In the Display panel, select the Degrees of Freedom view.
03:25
This view shows you the conducting elements in green,
03:28
representing the components to which you've added thermal loads,
03:31
And the insulated elements in red.
03:34
We want the heat to transfer through the entire model
03:37
but this view indicates that heat is not being transferred to the red components.
03:42
For effective heat transfer, the components need to know they're connected.
03:47
We use Automatic Contacts to generate contacts, using the default tolerance
03:52
which updates the assembly to ensure all model components contact each other.
03:57
Once the contacts are made, the entire assembly is seen as conducting.
04:02
Precheck shows there are no issues with the setup, so we can now solve the model.
04:16
When the analysis is complete, the result appear.
04:20
Change the temperature units to Fahrenheit, and notice that the temperature ranges
04:24
from 73 to 93 degrees Fahrenheit, which exceeds our 80 degrees goal.
04:30
We'll need to make some modifications to the heat sink to increase its surface area,
04:35
and thereby improve its ability to remove heat.
04:39
If we move the legend slider, so the minimum temperature reads roughly 80 degrees Fahrenheit,
04:44
we can see where, and how much of the model is above this.
04:49
We could use the Simplify environment to create alternative designs,
04:53
but for this model, we'll switch back to the Design workspace
04:56
and take advantage of parametric modeling.
05:01
The last item in our timeline is a circular pattern for the heat sink fins.
05:06
Double-click on the Circular Pattern and increase the number of fins to 40.
05:12
Then click OK to update the model
05:18
Back in the Simulation workspace, you'll see the previous results are still displayed.
05:23
However, there is a warning that the results are not up-to-date
05:27
and notice that the model still shows only 3 fins on the heat sink.
05:31
We'll return to the Setup tab to update the study settings.
05:36
Edit the Convection load
05:39
and clear the current Face Selection
05:42
Then, reselect the faces that represent all 14 fins
05:51
and the bottom face -
05:55
Check Precheck and fix any issues, then solve the job again.
06:07
When the results appear, notice the temperature range is roughly the same.
06:11
But when you adjust the legend slider to 80, you'll see that the temperature is all internal
06:16
and close to the drivers for the LEDs themselves.
06:20
This gives us the result we are looking for,
06:22
but you can continue to make design changes to improve it further.
06:26
In this lesson, we edited the Simulation model
06:29
to remove components that have negligible effect on the simulation,
06:33
we applied temperature loads to the model to represent the heat loads,
06:38
we checked the contacts to ensure that heat is transferred properly through the model,
06:43
we ran a thermal analysis and reviewed the results,
06:46
and we edited the Design model to improve heat dissipation and then reanalyzed the study.
For more, see Thermal Loads.
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