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Old   October 25, 2012, 09:56
Default Question regarding non-uniform FVM staggered grid and order accuracy
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Hi,

I have a question regarding non-uniform FVM staggered Cartesian grid and order accuracy.

When the grid is non-uniform, I define the u,v,p grids such that the east/west faces of the u grid intersects the cell center of p. Same for the v grid.

In that case, the distance of the east/west faces from the cell center of u will be different. the volume of u and p cells are different.

When using the fractional method, after evaluating the pressure from the Poisson eqn, to get u velocity, I use:

u(n+1) - u(*) = -(delta_t / vol) * pressure(east face) -pressure(west face) * area, where u*) is the intermediate velocity

However, since my u value is not at the center of the cell, it will not give a 2nd order solution, is that so? How can I resolve this?

Thanks
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Old   October 25, 2012, 11:22
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Filippo Maria Denaro
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Quote:
Originally Posted by quarkz View Post
Hi,

I have a question regarding non-uniform FVM staggered Cartesian grid and order accuracy.

When the grid is non-uniform, I define the u,v,p grids such that the east/west faces of the u grid intersects the cell center of p. Same for the v grid.

In that case, the distance of the east/west faces from the cell center of u will be different. the volume of u and p cells are different.

When using the fractional method, after evaluating the pressure from the Poisson eqn, to get u velocity, I use:

u(n+1) - u(*) = -(delta_t / vol) * pressure(east face) -pressure(west face) * area, where u*) is the intermediate velocity

However, since my u value is not at the center of the cell, it will not give a 2nd order solution, is that so? How can I resolve this?

Thanks

I suggest to see the dedicated part in:

http://onlinelibrary.wiley.com/doi/1...d.613/abstract
http://onlinelibrary.wiley.com/doi/1...al+maintenance

hoping this can help you
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Old   October 26, 2012, 03:11
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Thanks Filippo, I'll take a look at them.
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