[FLASH-USERS] Some questions about the new Flash.

[Klaus Weide]

On Wed, 26 Sep 2012, Norbert Flocke wrote:

> Hi Giovanny,
> 
> Here is the answer to one of you questions:
> 
>      the simulation run ok~E but for calculate the force I need to find
>      dR*dZ, so I call dvol from domain and divide over 2*pi*x(i). The
>      result is exactly 2E28 when I perform the sum. So, this is ok.
>      (Nevertheless, I don't understand why I must to divide over 2*pi*x(i)
>      and no only over pi*x(i)?~E the cylindrical volume in 2d is
>      pi*dR^2*dZ, no?)
> 
> The dvol in cylindrical coordinates is calculated as a difference between two
> cell boundary radii: r and R. So we have:
> 
>      dvol = pi * (R^2 - r^2) * dZ

Yes.  Also, please see the User's Guide section on

  8.11 Grid Geometry,

in particular

  8.11.4.2 Cylindrical geometry

for the meaning of "cell volume" in cylindrical coordinates.

Klaus