T-Junction Case Study: K-Omega Dissipation rate control?

paulnardone · July 31, 2014, 15:41

hello Folks,

I'm doing a little V&V work with some people, and we thought that a certain widely studied T-Junction Benchmark might be a good case study to support this work.

we're using steady state K-Omega SST physics and having a little trouble matching the results of the benchmark.

I know from literature that many used unsteady and LES simulations instead of the conditions I described, but for our purposes based on the bigger picture we wanted to try to get within a reasonable range with our method.

after a little bit of discussion with some of my superiors it was suggested that I find out some settings for this model that might be under-predicting/underestimating the dissipation rate.

I'm a semi-skilled user of the software but not a massive fluid physics math kinda guy so I'm mostly talking about how to manipulate the K-omega model in CCM+ to effect the dissipation rate...

I'm a little worried I might not be able to use this model anymore based on what it's been outputting so I'd love a little insight from the CFD community

Please dont be too harsh on me if i sound a little less-than-knowledgeable about this subject I'm still learning...

P

npoutre · August 7, 2014, 14:53

Can you elaborate a little more on what you are trying to measure and how far off from literature you are? Is this 2D/3D? Is this internal flow through some channels or pipes? What turbulence specification are you using and what are you using for the initial conditions of those specifications?

July 31, 2014, 15:41	T-Junction Case Study: K-Omega Dissipation rate control?	#1
paulnardone New Member Paul Nardone Join Date: Sep 2011 Location: Lawrence KS Posts: 3 Rep Power: 14	hello Folks, I'm doing a little V&V work with some people, and we thought that a certain widely studied T-Junction Benchmark might be a good case study to support this work. we're using steady state K-Omega SST physics and having a little trouble matching the results of the benchmark. I know from literature that many used unsteady and LES simulations instead of the conditions I described, but for our purposes based on the bigger picture we wanted to try to get within a reasonable range with our method. after a little bit of discussion with some of my superiors it was suggested that I find out some settings for this model that might be under-predicting/underestimating the dissipation rate. I'm a semi-skilled user of the software but not a massive fluid physics math kinda guy so I'm mostly talking about how to manipulate the K-omega model in CCM+ to effect the dissipation rate... I'm a little worried I might not be able to use this model anymore based on what it's been outputting so I'd love a little insight from the CFD community Please dont be too harsh on me if i sound a little less-than-knowledgeable about this subject I'm still learning... P

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August 7, 2014, 14:53		#2
npoutre New Member Noah Join Date: Aug 2014 Location: Seattle Posts: 2 Rep Power: 0	Can you elaborate a little more on what you are trying to measure and how far off from literature you are? Is this 2D/3D? Is this internal flow through some channels or pipes? What turbulence specification are you using and what are you using for the initial conditions of those specifications?