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May 22, 2021, 21:48 |
Residuals not decreasing!
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#1 |
New Member
Ali
Join Date: May 2021
Posts: 2
Rep Power: 0 |
In a pipe reaching a bifurcation simulation, with first-order upwind I have no problems with residuals, and they decrease normally, then after convergence, I switch from first-order to second-order upwind, the residuals remain constants and oscillating at 10e-2.
I refined my mesh, I used different schemes (simple,...), but nothing changed. Why? What I have to do to solve this problem Just as a short description: Geometry is shown in the attached picture For the mesh: in the root, the element size is: 0.6 mm in the red sphere zone, the element size is: 0.3 mm for the boundary layer, the first layer thickness is 0.08, number of layers: 5, growth ratio: 1.2 the minimum orthogonal quality is 0.15 and the highest skewness is 0.84! inlet B.C: parabolic Velocity profile: 2*V_mean*(1-(r*r/(R*R))) outlet B.C: pressure outlet: 13332 pa Scheme: coupled Steady-state Thanks! |
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