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John222 January 26, 2011 15:31

Grid Independent Study for a car

I have a car and I need to perform grid independent study on the car, I have made the default mesh and it was OK however I need the grid independent study for better meshing.

Does anyone have a good website I can learn how to create grid independent study?

Thanks a lot, J

julien.decharentenay January 26, 2011 20:05

Hi J,

A grid independent study (which should be called grid dependence study) looks at how the solution evolves with the grid resolution. Here is how you can undertake such study:

1) Build a reference grid G;
2) Run the simulation on the reference grid (to a defined convergence level);
3) Extract relevant information (drag?);
4) Build a refined grid G-R1 (if you do it by the book it is refined by 2 in all directions);
5) Run simulation
6) Extract relevant information;
7) Build a refined grid G-R2 (refined compared to G-R1) and redo 5 and 6 on R2
8) Plot the relevant information as a function of G, G-R1 and G-R2.

The solution is grid independent if the information does not change with G, G-R1 and G-R2 (meaning that your grid R is "fine enough" to capture the physics/numerics/etc).

Hope this help.

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