Problem with AcuSolve

Rahul_P1

Hello,

I want to reproduce the experimental results of a FDA-study (https://fdacfd.nci.nih.gov/interlab_study_1_nozzle/documentation/) with AcuSolve. The experimental assembly consists of a narowing of the cross-section und afterwards a sudden expansion of a channel. The tests run with different flow conditions (Re = 500 till Re = 6500 in the narrowing). If the Re is greater or equal 2000, it is getting intresting. To gain experience with AcuSolve I want to simulate the “easy” laminar flow (Re = 500). But there are aleady problems.
I generate 3 meshes with HyperMesh. The first one with about 150000 elements. In the narrowing the axial velocity along the centerline (z-axis) oscillates. After changing the simulation conditions, like the number of time steps, the time increment, the convergence tolerance, the relaxation factor and so on, without an effect on the results. Becuase of that I generate a second mesh with about 300000 elements. The axial velocity along the centerline does not oszillate any more, but it is to low. With a mesh consists of about 900000 elements the axial velocity drops again.

My supervisor, Mike Nicolai, and I have no more ideas. Can someone help me?

Rahul_P1

Hi Cleansy,

Firstly let me assure you that this kind of validation can definitely be performed in acusolve,
Although the link you provided has detailed information, we still need information about your analysis to help you further

Please provide the inp file, this will tell us about your boundary conditions.
An image of the geometry or the geometry file itself (please use the secure file dropbox in the signature below)
The minimum and max stagger iterations specified.

Please add a note if the geometry is confidential, when you send a file through the secure dropbox I will be the only recipient and we will maintain confidentiality of the model to the best possible extent.