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Defining free space as domain
Posted 24 ago 2016, 06:42 GMT-4 Fluid & Heat, Heat Transfer & Phase Change, Geometry Version 5.2a 1 Reply
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Hi all,
i have an issue with Comsol. I have a CAD Model of an electrical box with some power components. Defining the materials and heat losses is not the problem as i can select the components without problem. To know how much the interiour heats up and how much the influence is to other components i want to simulate the heat transfer in fluid (air) inside the box, but i cant figure out how to define the free space. I already read the following topics here:
www.comsol.com/community/forums/general/thread/46155/
www.comsol.com/community/forums/general/thread/32396/
www.comsol.com/community/forums/general/thread/35578/
www.comsol.com/community/forums/general/thread/36376/
www.comsol.com/community/forums/general/thread/32396/
None of them appear to help me as i dont have a tubular object to use the "cap faces" nor a surface to use the conversation to solid function. Is there a way i can do it in comsol o is it better i reacte a negative volume in the CAD application and define it as my air domain?
To simulate the walls of the box is not of my interest as it is quite isolating and closed, so i only use it for visualization purposes to create plots that are nearer to the physical model on my desk.
Thanks,
Adrian
i have an issue with Comsol. I have a CAD Model of an electrical box with some power components. Defining the materials and heat losses is not the problem as i can select the components without problem. To know how much the interiour heats up and how much the influence is to other components i want to simulate the heat transfer in fluid (air) inside the box, but i cant figure out how to define the free space. I already read the following topics here:
www.comsol.com/community/forums/general/thread/46155/
www.comsol.com/community/forums/general/thread/32396/
www.comsol.com/community/forums/general/thread/35578/
www.comsol.com/community/forums/general/thread/36376/
www.comsol.com/community/forums/general/thread/32396/
None of them appear to help me as i dont have a tubular object to use the "cap faces" nor a surface to use the conversation to solid function. Is there a way i can do it in comsol o is it better i reacte a negative volume in the CAD application and define it as my air domain?
To simulate the walls of the box is not of my interest as it is quite isolating and closed, so i only use it for visualization purposes to create plots that are nearer to the physical model on my desk.
Thanks,
Adrian
1 Reply Last Post 31 ago 2016, 07:07 GMT-4
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Posted:
8 years ago
Hi Adrian,
Provided that you electrical box is an airtight enclosure you can do this as follows:
1. Draw a box that is larger than and completely encloses your electrical box.
2. Use a Union operation to compute the union of the box you have drawn together with all other objects that represent your electrical box and enclosed components. By default the Union operation preserves internal boundaries and computes the appropriate domains, like the air region.
3. Using the Delete operation delete the domains, such as the region of the box outside the enclosure and hardware domains that are not required.
If the original enclosure is not airtight you will need one or more steps to partition the remaining air domain after step 3. You can do that by using for example a work plane to create a surface for partitioning or the Cap faces operation if there are some edges you can select.
Best,
Lorant
Provided that you electrical box is an airtight enclosure you can do this as follows:
1. Draw a box that is larger than and completely encloses your electrical box.
2. Use a Union operation to compute the union of the box you have drawn together with all other objects that represent your electrical box and enclosed components. By default the Union operation preserves internal boundaries and computes the appropriate domains, like the air region.
3. Using the Delete operation delete the domains, such as the region of the box outside the enclosure and hardware domains that are not required.
If the original enclosure is not airtight you will need one or more steps to partition the remaining air domain after step 3. You can do that by using for example a work plane to create a surface for partitioning or the Cap faces operation if there are some edges you can select.
Best,
Lorant