Learning Forum

[Diogo Martinho]

Hey, 
I came across a paper where they defined a pressure inlet at a diameter 0.8mm and 20 bar.
This are the results of "Fig6".
However, When I tried myself I got such a small mole fraction profile. Not even comparable to the previous plot. 

Any sugestions of what is going on? 

[Rob]

You mean the jet penetration is too low? Please zoom in and show the mesh. 

[Diogo Martinho]

 

Hi Rob, 

Thanks for your time

yes, I think it doesnt make a lot of sense such a small jet penetration on the domain. the operating pressure is atm and the pressure inlet is 20 bar.

 

 

[Rob]

Replot with node values off, and then tell me why you think the jet should penetrate the domain with that level of mesh refinement. 

[Diogo Martinho]

 

So if my mesh is much finer, will the jet propagate more? 

 

[Rob]

Not necessarily, but with a coarse mesh you'll see far more false/numerical diffusion. Most courses teach y+ for meshing to the exclusion of all else. They neglect to mention that you must also resolve the farfield and all flow features. Repost the image, and then tell me how well you think the jet is resolved.