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 Dimitris February 12, 2010 07:35

ANSYS Multiphysics Bearing Simulation

Hello everyone,

I am trying to simulate a journal bearing system via ANSYS Mutliphysics with FLUID142 elements. I have created a macro with witch I handle all the specifics of the simulation (geometry, boundary conditions etc). The solution process concludes normally but the results that I am getting are allways twice the normal value. I have checked my input and all seem to be right. No systematic/arithmetic error has been detected. Both the maximum pressure angle and the resulting pressures are wrong with the latter being two times higher than the appropriate ones. The residuals are very low (below 1e-6). Velocities on the other hand and all the relevant properties of the fluid are correct. In brief my boundary conditions are:
1.Tangential speed of journal in journal surface
2.Sommerfeld Condition is apllied directly to the (appropriate) half of the flui volume
3.Velocities of bearing walls are set to 0
And the most curious is that I am getting the same results both in 3D and 2D simulation (i have made both 2d and 3d models)
The coordinate system is Cartesian.

Thank you

 hosseinhgf September 24, 2010 11:42

hi
i have same problem.
i use cfx to simulation a journal bearing in 3d. the mesh is 700*15*30(theta,r,z) from gambit.i know the half sommerfeld condition must be applied but i dont know how.the pressure and force on journal is bigger than the real results.
d=50mm
L=25mm
mu=1.25e-2
eccentricity ratio=0.5
attitude angle=49
clearance =0.05mm
is it suitable to simulation with ansys mutiphysic?
how you can use half sommerfeld condition?

 arz83 November 10, 2011 06:17