CFD Online Discussion Forums - finding radial velocity using continuity equation

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Programming & Development (https://www.cfd-online.com/Forums/openfoam-programming-development/)

- - finding radial velocity using continuity equation (https://www.cfd-online.com/Forums/openfoam-programming-development/194317-finding-radial-velocity-using-continuity-equation.html)

finding radial velocity using continuity equation

I want to calculate radial velocity from axial velocity using continuity equation

w(scalar) is known (axial velocity). I want to calculate radial velocity v(scalar) assuming azimuthal component is zero. (Theta is the angle of the line connecting cell center to the origin in the xy plane). So from continuity equation I obtain

$\frac{\partial v(cos \Theta) }{\partial x} + \frac{\partial v(sin \Theta)}{\partial y} = - \frac{\partial w }{\partial z}$

It seems the process involves solving a set of linear equations.

Code:

  

fvScalarMatrix vEqn

(

         fvm::__________

);



solve(vEqn == __________)

Can someone help me
Thanks