Hello, can someone give me a hand? I have to do a CFD analysis in Ansys Fluent of a rocket that we are going to manufacture for the student association I belong to. The problem is that the CAD file, as it is designed to be manufactured, has a lot of clearances and holes and when I import the geometry, put the enclosure and extract the geometry, as it has clearances the mesh gets into the gaps. Is there a simple way to change the CAD so that it only takes the outer surface (as if I put a cloth over the Rocket).

I use alibaba cloud for my simulations and I want to ask for the specific context of either compressible or incompressible flows how many cores are reccomended.

Would the members of the group be interested in a Software Development Primer. This would not be a "How to program in Python / Java / C++" kind of Primer, but rather what makes a person a good developer versus a person who just knows how to program somethin in Python?

The following comes from a couple of comments I made, and I thought it might help to have these comments not buried in a post. So... Why CFD? CFD will very rarely match complex flow reality. It can, but the level of effort required is considerable, so it's very rarely done. That said, it is very important to keep in mind what, exactly, you are running the CFD simulation for? - Are you trying to match complex experimental results? - Are you trying to approve / discard designs? - Are you exploring a prototype in detail? - Are you trying to validate the code? etc. If you want to match experimental results, you are probably going to need A LOT of nodes on the cluster, and all the RAM you can beg, borrow, or steal, because your cell count is going to be in the hundreds of millions. This is called Direct Numerical Simulation (DNS), it is difficult and expensive. And be ready to restart that simulation a dozen times while you tweak the ICs, BCs, and relaxation factors. On the plus side, setting up the physics is dead simple, since you won't have any turbulence models, or any other models that attempt to handle complexities in simple ways. Let's talk about physics models. What is a physics model? What is a turbulence model? A turbulence model is, by definition, a simplified model of the turbulence a given flow field will experience. While the models are often very good, they are still models, built with a large number of assumptions, many of which are not correct, but which are "good enough". ALL of the models in a given CFD package are, in some way or another, a handy and acceptable simplification of the physics at play. Thus, they will never get it exactly right. Validating CFD software usually does match reality, because the cases used to validate are exceptionally well understood, and the tweaks are in the research paper everyone reads when setting up the validation case. These are the exceptions. Design exploration is where you want that high fidelity, but you can't afford it. You don't have the time or computing resources, so you go with the best fidelity you can and you target specific things. If I'm looking at how the flaps on a wing impact lift and drag, I'm not going to try to model the flow around the empennage, or through the engine nacelle. Those are getting some pretty basic assumptions and BCs/ICs, along with a coarse mesh, and I simply expect that the fidelity in those areas will be low. If I see evidence of some interesting fluid structures that could be the result of (for example) interactions between the flaps and the engine nacelle, then I'll refine the mesh and re-evaluate the assumptions.

HI every one Iam looking to develop my self in the CFD field ,my experience with CFD was doing aerodynamics CFD simulations in Ansys fluent for a formula student car just following the steps and recommendations from the resources we had found ,I Want develop my self more so I want to know the things that would help me reach a good level . the second question what is the day to day tasks look like for CFD professionals ? , thank u .