I have a doubt about the symmetry boundary condition in Fluent. I want to carry out a CFD analysis of flow over a car. Will using the symmetry boundary condition give the same level of accuracy as using the full model?

Mathematically it gives the same.

But your domain is really a symmetrical or not you should be sure with it first.

your boundary conditions should be also symmetrical

[hhh]

Dear friends,
i am doing 3D wing analysis, i have doubt on boundary conditions in fluent ie both symmetry and periodic, anybody have the answer please let me know briefly,for what kind of purpose to use symmetry & periodic boundary conditions, please tell any example with problem.

[tea restiana]

I simulate 3d seawater in the case of dispersion thermal analysis of the power plant cooling water using ansys fluent, the geometry and namely boundary conditions that I modelled is shown in the figure bellow. In modelling physical models used k-epsilon and active energy. the material used is only one phase, namely water. Temperatur normal seawater set 30℃ and temperature discharge outlet 37℃.The boundary conditions are discharged outlets, ambient inlet, outlet, ocean, seabed and seashore. The discharge outlet is the discharge area of the cooling water power plant modelled as an inlet velocity with a velocity of 1.71 m / s and a temperature value of 37℃, the ambient inlet boundary condition is modelled as an inlet velocity at 0.4 m / s and a temperature value of 30℃.Outlet modelled as outflow.Seabed and seashore as a wall.
For ocean boundary conditions I model as symmetry. what I want to ask, in my case is it okay if I model ocean as symmetry? Can anyone explain that? Or do I need to use other boundary conditions?

[RaiderDoctor]

Hi tea restiana,

So, a couple of things:

This is not how you ask questions on the forum. Don’t just go through and randomly dig up old discussions that haven’t had answers to them in years. If you need the specific answer that they arrived at, and it’s not listed, try sending them a private message. Otherwise, make a new discussion with your question, if one doesn’t already exist.

Furthermore, your question(s) (two, since you asked the same one twice on different forums) have little to do with the discussions in which you posted them. Please don’t do this, as it adds to the list of questions that forum members might take a look at. We’re all busy with our own work and research, and we want to help as many people as we can. But when people ask multiple questions on different posts, it might take away from other questioners as well.

Your setup is way too detailed, and not enough pics are shown to help us diagnose your problem. You should tell us enough pertinent info about your problem that will help us to assess it.

Now, on to your question: Determining whether you can use a boundary condition is your job as the investigator. What have others done? Have you ran both cases (symmetry and no symmetry) and compared? What are the benefits to splitting your domain in half? These are all rhetorical questions, there’s no need to answer them.

The program you show looks like Mechanical. Since this doesn’t look like an FSI study, this leads me to believe you aren’t using Fluent to simulate, in which case a different forum might better be suited to answer your question.