CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   Nusselt number variation over a ribbed surface (http://www.cfd-online.com/Forums/fluent/85857-nusselt-number-variation-over-ribbed-surface.html)

avi031 March 8, 2011 15:48

Nusselt number variation over a ribbed surface
 
Hi,
I am Avinash. I am working on "Heat transfer analysis in a turbine blade cooling passage of trapezoidal crossection"
Boundary conditions:
Inlet-Mass flow
Outlet-Pressure outlet
Two opposite surfaces of the passage are given constant heat flux and are of the same value. The surfaces have 45 degree ribs to enhance heat transfer coefficients.
Problem: I need to obtain the variation of nusselt number over the heated surfaces..therefore a central line was drawn over each of the surface and the surface nusselt number was plotted.....but unfortunately i am not getting realistic values of the nusselt number......lot of difference between the expt and cfd values. Convergence criteria was met. Realizable k-epsilon model was used. Can somebody pls provide suggestions in getting the suitable values of the nusselt number???


Regards
Avinash

foamcfd March 9, 2011 12:57

What is the value of y+. For your kind of analysis it should be less than 1. Also try using k-omega SST instead of K-epsilon.

Regards,

yogesh

avi031 March 10, 2011 13:09

@yogesh

my y+ value is 3.7:(...........i will use the sst k-omega model and see if i can get accurate values..your reply has been helpful....thank you very much


All times are GMT -4. The time now is 12:51.