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martinD July 6, 2010 06:30

heat transfer convergence
 
Hi,
I am performing RANS simulation on jet impingement (full 3D model) with SST tur. model. I am wondering why the heat transfer convergence is so bad, while the momentum and turbulence are good.
Thx, Martin

ckleanth July 6, 2010 06:31

what are the y plus values ?

martinD July 6, 2010 07:00

Quote:

Originally Posted by ckleanth (Post 265914)
what are the y plus values ?

y+ < 1, actually I was running similar simulation before, only for a 5 degree cut out. there the RMS convergence was comparable. in this case the momentum and turbulence RMS is <10^-5 after 500 iterations, while the heat tr. RMS ~ 5x10^-4 (1000 it.).

ghorrocks July 6, 2010 18:42

Errors in heat transfer are typically 20-40% in turbulence modelling, especially when looking at local heat transfer rates (rather than global heat transfer). It is much harder to get heat transfer right compared to momentum. This is explained in any turbulence modelling textbook.

martinD July 7, 2010 02:30

thanks for reply.
Martin


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