CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   How to output the vorticity fig? (https://www.cfd-online.com/Forums/main/12409-how-output-vorticity-fig.html)

aiya October 15, 2006 13:24

How to output the vorticity fig?
 
In many papers, the vorticity fig can be seen, so if we have the u.v.w flow field, how to draw the vorticity fig.

Who have such experience or give some sample codes.

Thanks!

Harish October 15, 2006 21:43

Re: How to output the vorticity fig?
 
Have a simple subroutine to calculate the vorticity, which can be done once you have the velocity values.The equations for 2d and 3d can be found in any introductory fluid mechanics book.


aiya October 16, 2006 07:47

Re: How to output the vorticity fig?
 
hi.. Harish Now do you have such subroutine, can send me one to learn? Thanks much! mud2003@126.com

dingxi October 16, 2006 08:33

Re: How to output the vorticity fig?
 
for 2D, you can a vector vorticity field with + or - stating its directions. For 3D, the vorticity is a vector having three components in three directions. Hence it is convenient to have the magnitude of the vorticity. vortiticy is the curl of velocity vector. Google it and you will know

aiya October 16, 2006 12:29

Re: How to output the vorticity fig?
 
hi.. dingxin

Do you mean : "wx = dw/dy - dv/dz wy = du/dz - dw/dx wz = dv/dx - du/dy w = wx(i) + wy(j) + wz(k) vorticity magnitude = sqrt(w.w) = sqrt( wx*wx +wy*wy +wz*wz) "

but as if the solution for the boundary is difficult? I do not know how to do

ag October 16, 2006 13:57

Re: How to output the vorticity fig?
 
Just use standard differencing formulas to numerically differeniate the velocity field. It's really not that hard to do.


All times are GMT -4. The time now is 03:11.