How to Easily Create Models with Two Separate Air Regions in Classic and AEDT Icepak

How to easily create models with two separate air regions in Classic and AEDT Icepak Hello, this is Mert Berkman with Ozen Engineering, and this is another edition of our engineering videos. This one is particularly on Ansys Icepak and AEDT, where I'm going to look into a problem.

Thank you for watching this video. The problem is we have two separate air domains. One is, you know, as our vehicle is traveling through air, it's the external flow, right, outside our object.

The other is this internal flow within the cavity, or on the inside of our vehicle, where, you know, we have the heat load that needs to be conducted away.

So, in order to do this in Icepak, what I'm going to do is, I'm not going to even define fluid blocks, I'm just going to use this and take advantage of some of the Icepak capabilities without sealing the domain, etc.

So, let's say we have our CAD, it's pretty clean, then what we're going to do is we're going to go to Icepak. We want to convert these objects into Icepak objects. This is particularly for classic Icepak.

For AEDT, we really don't have to do anything, we can just directly import this CAD model in any format into AEDT. Okay, so let's start using AEDT's simplify function. So here, the skin is a complex object, but like our heat sources, we can do a polygon fit.

Click on the color change and again, the heat pipe is a simple pipe, so that's also level 2, which will work, so that also changed, but our skin, as you can see, is a more complex geometry, so we're gonna select CAD object, maybe, ok, have like the good quality, best quality, click on it, and as you can see, the tessellation is pretty fine, so that looks very nice.

What I'm going to do is I'm going to save this as a Discovery file called model. Now, just hit save, right, so it just saved. And then, you know, we can start working on the classic model. So I'm going to just, you know, move on to Workbench now. Now Workbench is open.

I'm going to go ahead under component systems, add this geometry, and I'm just gonna say hey, import geometry, and let's browse, make sure we get the right model, and then we're gonna go pick this one, make a copy of it.

The next step is, you know, adding an Icepak model, so now you, if we double click on setup, it's going to call Classic Icepak. Alright, so we're in Classic Icepak, and we see automatically an enclosure has been added around our object.

But I'm not happy with the enclosure size, because we're going to solve external flow around the skin. So I want to increase the sizing, so I go to cabinet, or rather, even I can just stay here, and I want to add some distance here, and also add maybe like 10 millimeters all around our object.

So if I hit enter now, what we see is, you know, there's enough air space created around our object to predict accurately the external flow. Right. Okay. So that's good. Next step, what we want to do is define our boundary conditions. And this is where we're taking advantage of AEDT.

So here, you know, even though we defined one enclosure, and we talked about, you know, resolving the external flow around our object. So, you know, this way we got our external volume.

But not only that, actually, with these settings, if we select outlet on this back face for external flow, if you have a lab model for the air domain, for the internal or the external, with one shot, with a simple cabinet, we're essentially defining both of the air volumes without any effort.

So let's go to our cabinet now, you know, we defined our geometry, we go to our properties, so at min x, right, we wanna have an opening where it actually is an inlet. If I go there, I want to define an x velocity of maybe 10 meters per second, right, update done.

And then at max x, this is going to be again an opening, but it's going to be a pressure outlet, so we don't have to touch anything. I'm just going to use automatic cut cell meshing. A lot of times I just try the first option, I'm just going to select medium, and then hit accept.

So this is essentially going to go start generating a mesh, and typically, you know, we get a good mesh quality. If this does not work, we're going to use the second option. So very quickly, around 220,000 cells have been defined. Let's typically, you know, let's do a cut plane check.

So let's see if the skin is resolved properly. If we have two separate fluid zones, so we can make sure. Okay. See, we see some, okay, decent resolution there. So let me do solids only.

And as you can see, the skin is resolved, the skin is solid, and you know, it's resolved with a single cell, which is not ideal, but that's fine.

If we switch to fluids only, you can see two totally separate fluid domains, and you know, this was done without defining any enclosure or any fluid domains, any fluid shape. So that is actually what I wanted to demonstrate for classic Icepak in this tutorial.

Next step, we're going to look into how to do the same thing in AEDT. So in our AEDT session, let's go import our model. Alright, so let's see. As you can see, automatically an error domain is placed around the object with some padding around.

Unlike classic Icepak, AEDT by default puts some padding, so that also saved me another step of resizing our enclosure. But what I need to do is to be able to use this face as a wall in the Z direction, I would need to pull back to where the skin is.

So to do that, I'm going to double click on create region, and these are the paddings. So I want to make the padding in the plus X direction 0. So plus X padding should be 0. I'm just going to hit OK. And then I can assign these four faces as openings, free, and just pressure boundaries.

And then this bottom face, you know, we want it to be a wall. So we're gonna do just a stationary wall. And that's it. So where we kind of, you know, set up our model. Next step is let's generate our mesh. So we go to simulation, we're gonna do global mesh settings.

I'm just gonna start typically with level 3, and let's see what we get. You know, it's one-click meshing, then, you know, after saving the file. So now, you know, it started working on the mesh, and it came back with some errors, right? What I had forgotten was to assign materials.

So what I'm going to do is for these, you know, to be quick, I'm just going to assign them, you know, aluminum. Later, you know, we can change those, you know, as needed. So the goal is to quickly get a mesh. Again, hit the generate mesh, and it started working.

And it was done very quickly, so we have 39,000 cells. What I would like to do is I want to hide these guys. Thank you for your attention. Have a good day. Thank you for watching. Please contact us at https://ozeninc.com/contact for more information.