[nikos_]

Good Evening,

I want to calculate the partial derivatives of radial and circumferential velocity to z direction to use them in calculation of shear stress (ShearStress_(z,theta).

i've already find out how to define and export them from CFD-Post but i want to calculate them via a UDF script. From my researchment in udf-manual i see that it is possible to calculate the gradients of u,v,w (towards x,y,z -Cartesian Coordinates) but how about gradients of u_radial, u_theta, u_axial (towards r,theta,z -Polar Coordinates)?

Any infromations, guides and references about the writing of the above udf script are more than welcomed.

Nikos