Axisymmetric UDF, source terms in cylindrical coordinates
 

Hello CFD Online Community!

I am simulating a flow through an axisymmetric geometry and therefore I use the axisymmetric solver in ANSYS Fluent. For my problem I need to solve the enthalpy based Energy Equation and therefore I use a UDF. In this UDF source terms occur which have the divergence of the velocity and also partial derivatives of the velocity components. So now my question is: Do I need to implement these source terms in cylindrical coordinates or can Fluent transorm the cartesian implementation?

As an example the implementation of the divergence of the velocity in 2D cartesian:
C_U_G(c,t)[0]+C_V_G(c,t)[1]

If some of you also know how to define the divergence in cylindrcal coordinates for the UDF I would be very happy.

Best regards,
Manuel