Problem with interpolation

Ramu

I will explain my problem clearly.

I have a cylidrical domain(which is for LES of the round jet), I want to DNS of this round jet.if i increase my grid ressolution with this cylindrical domain for doing DNS, time

step is becoming very low(NAN), it is due to the very small mesh size around the axis of the jet, now i want to replace this cylindrical system with carstessian grid, but here

what i need is i am doing the DNS from (domain in axial direction)3d to 20d where d is the nozzle diameter.for this i am taking the LES (cylidrical domain) data at 3d of jet as

inlet B.C for my DNS(this is cartessian grid just superimposed on cylidrical gird of the LES domain at inlet plane), now i want to inerpolate this LES cylidrical domain data to

my cartessian grid.. I think now u can understand my problem very clearly,please let me know ur suggestions

Thankyou in advance