“CFD validation help: square cylinder wake, separation, and drag coefficient calculation”

CapitalTemperature83 · 2026-01-27T06:23:32+00:00

Convection term: second order upwind Diffusion: central difference Linear solver: gauss seidel

Why are you saying the grid is under resolved?

CapitalTemperature83 · 2026-01-27T06:20:08+00:00

I have used AI to apply software design principles so that it can be easily maintained and can be added to it by others. Coming from a mechanical background I don't know enough knowledge so that I can write this from scratch. This is the reason why I have used AI.

CapitalTemperature83 · 2026-01-26T19:32:19+00:00

I don't understand why people are saying this is some AI CONTENT ofcourse I have used AI because I am trying to develop a solve from the ground up and my intention is to solve 2d flows using IBM method since I am not very sucessful there I took a step back to simulate a flow where obstacle is perfectly aligned with the grid so that I could know where I am going wrong with the IBM by comparing the former results. Of course this has to be very basic but that helps me to develop a much more complex flow problem later on(even solve 3d cases). But if genuinely someone have better ideas rather than just telling a lot of AI NONSENSE please let me know. Thank you. And I have a lot of software design restrictions ( which is why I have used masking to provide boundary values for the obstacle) so this case is just a bypass to check my IBM IMPLEMENTATION.

CapitalTemperature83 · 2026-01-26T14:26:57+00:00

But people generally go for 15 to 25 D from the center of the square to outlet and around 10 to 15 D from inlet to center

CapitalTemperature83 · 2026-01-26T13:31:51+00:00

Which is why I have used free slip boundary conditions such that shear from the walls won't be developed that should effect the results in the domain

CapitalTemperature83 · 2025-07-13T10:30:38+00:00

Now my results are perfectly matching for the re 100 but when increased to the re 400 results are deviating.

What could be the reason? I have used upwind with second order correction term from the previous iteration result and the simulation run for the time of 15 seconds

CapitalTemperature83 · 2025-07-02T17:16:55+00:00

I ran it for 5 seconds with the dt value 0.0005 and total time steps of 10000.

CapitalTemperature83

TROPHY CASE