3D casting represented as 2D section at symmetrical plane

[OmkarJ]

Hi,

I was curious about how much I can push the simplification in CFD modelling.
Please have a look at following image:



My goal is to find the optimum angle  for a casting, which obviously is 3D, so that I have least pressure drop. So I may need to create a series of 3D models with different  to get a trend and then  I know the minima of a curve of pressure drop versus , which is optimum value.

Now, I was thinking, if i only create a 2D sketch of this model with different  and obtain the optimum value, I can have some guidance about optimum angle for 3D. Agreed, the actual casting has cylingrical features and I am representing it as 2D, and the physics is entirely different. But what I want only, is to get closer to optimum value through the series of 2D simulations. Suppose if I find that the optimum angle for 2D section is say 50 deg, I can then take series of angles close to 50 and run 3D simulations. 

I want to emphasize that It is not about exact result of 2D, but about zeroing in on the range of of angles I need for 3D simulations that I want to focus on, with a premise that optimum angle for 2D and 3D will not be miles away from each other. It is far better to run with range of angles at 45, 47, 50, 53 and 55 deg instead of running with range of 30, 40, 50, 60, 70 deg, to get the accurate inflection point of the curve, to find optimum angle.

Does this approach sound reasonable? Or am I missing something terribly obvious?

Thanks!

[Royce_adsk · Accepted solution]

Hi Omkar,

I think the idea is sound so that maybe you can reduce your range of runs for 3D and try to hone in on the results faster. I think this might come down to what range of theta are you looking at and do you want your optimization down to a degree, 5 or something else? If 2D has a close enough accuracy of X° compared to your final optimal results will that be enough? Hard to say until you run.  Running 2D is fairly easy and cheap on time. Could you share what you learn?

My 2 cents from the support team 🙂

[OmkarJ]

Yes Royce, the rationale behind this simplification is to get the answer sooner with less computational overhread. But the final decision will be based only on 3D results, run at close range arrived at using results of 2D. It is same as first adjusting a coarse focus and then fine focus for a microscope when you are observing the slides to tune the focus quickly.  I will post if I find anything interesting