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No Convergence in Channel With Jet Impingement |
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#1 |
New Member
Christian
Join Date: Dec 2021
Posts: 6
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Hi there,
I am running a simulation of a channel with a mainstream flow, intercepted by a flow of a high velocity jet at an angle. The jet impinges onto a heated surface, then both flows exit at the end of the channel. I am having a hard time getting Fluent to converge to 10e-6, with residuals converging to about 5e-4 and then oscillating about that value/ I have heard that oscillation could be due to inadequate inflation layers, so I increased the number of inflation layer elements on all surfaces, but I am still getting no convergence after many hours. Can anyone suggest any fixes? The working fluid is air, modeled as an ideal gas, k-epsilon turbulence model, gravity enabled, and the SIMPLEC method (Coupled method does not come close). Mainstream velocity is 10m/s (Re = 19,000; Ma = 0.03) and temperature is 303.15K. Jet velocity is 50m/s (Re = 49,000; Ma = 0.14) and temperature is 303.15K. Jet intercepts main flow at 45 degree inclination. Channel exit is given the "outlet vent" boundary condition. A picture of the failed residuals is attached. |
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#2 |
New Member
I do CFD
Join Date: Mar 2022
Posts: 7
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why donīt you use pressure outlet rather than outlet vent?
Outlet vent boundary conditions are used to model an outlet vent with a specified loss coefficient. |
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#3 | |
New Member
I do CFD
Join Date: Mar 2022
Posts: 7
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also it may be the mesh resolution problem. 1e-6 convergence may need very fine mesh
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#4 |
Senior Member
Lorenzo Galieti
Join Date: Mar 2018
Posts: 375
Rep Power: 12 ![]() |
If anything, finer mesh hampers convergence, doesn't improve it xD.
Can we see the flow field? Maybe it's just that it doesn't find a steady state solution... Can sometimes be possible. I would anyways stick to the coupled method. |
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Tags |
convergence, fluent, residuals |
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