Help !!! CFX4.2 users

Athar Zaidi

I am having lots of trouble modeling non-Newtonian turbulent flow with Low-Reynolds number k-omega model ( Wilcox 1993) through stenosed arteries segments , either the values of omega and K decreases to unsual values , something of the order of 10e-40 or the solution blows up. I am using CFX 4.2 ( Aea Technology) CFD solver which is a finite volume based solver. I specify my strain rate based viscosity in USRVIS subroutine and set VISN(INODE,IPHASE) =Vlaminar+Vturbulent. It seems to me that nobody has done a simulation of non-Newtonian turbulent blood flow using low-Reynolds number model till now. However I get some good results with high Reynolds number RNG K-epsilon model, but my flow operates at Reynolds number below 10000. I was wondering if Any one has any clue that may be K-Omega model has a deficiency in this respect, I mean modeling strain rate based viscosity. I couldn`t find such deficiency in literature so far.Please reply soon.