Axisymmetric Flow

S. Kumar

Hi,

Can anybody help me understanding the finite-volume method for axisymmetric flow? For theory and implementation I am using " Computational Methods for Fluid Dynamics-2nd Edition." by Joel H. Ferziger & M. Peric. and accompanying CAFFA code. I have two points regarding this :

1) On pages 244-246 it explains that general Cartesian code can be adopted for axisymmetric flow if some additional terms are added. Can you please help me understand why it is needed to add the radial component of pressure forces on the front and back surfaces?(page 245) I am also not very clear how this extra term is derived in here. There is a very sort explanation of this fact in here. Is it possible to give some references which treats this in greater details?

2) By studying CAFFA code it appears that gradient vector components at CV-centre for U, V and P all use above mentioned correction terms for axisymmetric flow. Subroutine for calculating gradient is

GRADFI(K,FI,DFX,DFY)

In this subroutine correction for axisymmetric flow is provided and this subroutine is called by another subroutine

CALCUV(K)

This calculates the velocities component.

My question here is -- why is it required to add correction term(1)for all the gradients ?

I will greatly appreciate any help in terms of explanation or reference.

Thank you very much

S. Kumar.