How to use K-e model ...
 

Hi Friends I have one question in my mind. can anybody tell me more about it.

My problem is like this: tank of size 1m X 1m X 1m. the inlet is only 6mm jet flow(fluid is water) with Re=13,000, outlet is 0.003m X 1m. Now my doubt is regarding the use of K-E turbulence model for simulating the entire tank. Major part of the tank is having cell Reynolds Number less than 200. hence if i use K-E realisable model for simulating the flow in the tank, will it be correct? Is there any method for such problem( both laminar and turbulent flow in a same domain without any demarcation)?

Re: How to use K-e model ...
 

k-e RNG is so great for those fields which you have laminar flow and turbulent , bt any way i think you can use all k-e methods.

Re: How to use K-e model ...
 

Hi, you can select a region with Adapt/Region and Separate the selected cells (Seperate/Cells) from the entire geometry. Then, with this new volume, called " fluid: xxx", you can put on it a "Laminar Zone" in boundary condition. And select you k-e model from the viscous menu !

Re: How to use K-e model ...
 

hi, Thanks for your useful reply. For using adoption/region, we have to solve the complete domain assuming that it is turbulent flow. After this output will become basis for next adoption/ region. Therefore my doubt is regarding how to start simulating. Even in some part of the domain,if Re is less than 200 what happens if i use K-E model?

What criteria shall i use for marking laminar and turbulent regions? (i,e., Re= ?) Can you through some light on these doubts?