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#21 | |
New Member
MK
Join Date: Aug 2009
Posts: 22
Rep Power: 17 ![]() |
Quote:
u(r)=u_max (1-(r/R)^2), where u_max=1.5*u_avg, for 2D cartesian u_max=2*u_avg, for axisymmetric problem for turbulent flow, you can use 1/7 law but I think the velocity distribution does not affect the results severly. |
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#22 |
New Member
MK
Join Date: Aug 2009
Posts: 22
Rep Power: 17 ![]() |
dear Anindya!
you should consider to your computatinal domain. the width of domain (from symmetric plane to outlet) must be large enough to use pressure or outflow condition (say 10 to 15 times more than D). also, you should note that what kind of impinging geometry you have (i.e., confined or unconfined). |
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#23 |
New Member
anush
Join Date: Jan 2012
Posts: 9
Rep Power: 14 ![]() |
hi, everybody i am new to the gambit and fluent software, and i needed help solving a converging nozzle problem,i am not getting the convergence in iterations, its actually showing lot of divergence during iteration process,
and it ends with warning like reverse flow at outlet and turbulent flow at outlet. i have selected viscous flow to be -spalart allamaras and the courant number as 5. i have used solver as density based and fluid as Air(property-ideal gas). As the iteration progresses the reverse flow and turbulent flow error is shown, after 80-90 iterations it shows divergence and accordingly it reduces the courant number from .5 to 5e-5 for each iterations and it ends with floatation error. below is image of my model- the white region is wall, the pink region is pressure far field, and grey(ish) region is pressure inlet. i need to find the flow characteristics of compressible flow in nozzle. plz plz plz reply asap... thank you for your time |
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#24 | |
New Member
MK
Join Date: Aug 2009
Posts: 22
Rep Power: 17 ![]() |
Quote:
I think the problem is caused by your pressure far field boundary. there is a limitation to use this kind of condition, that the far-filed boundary should not have broken edge (like a cube) you must use a curved surface instead of broken one. use a half-sphere instead of this cube. |
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#25 | |
New Member
anush
Join Date: Jan 2012
Posts: 9
Rep Power: 14 ![]() |
Quote:
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#26 |
New Member
Mark
Join Date: Feb 2016
Posts: 1
Rep Power: 0 ![]() |
Hi All,
I am tasked with modelling a 2d axisymmetric jet impingement on a flat plate but I have no clue how to begin modelling this. Can anyone help with this? Thanks Mark |
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