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stanicm

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  1. Hello. I have noticed that your entire case seems to be in meters. That means that your dx = 1 [m] and that your domain spans from -180 [m] to 460 [m] in y-direction, implying your gearbox simulation is operating on a kilometre scale. Now, I imported the stl files you sent in ParaView and noticed that their scales are normal, meaning spanning approx. -0.15 [m] to 0.4 [m]. Your motion definition in the .cfg file is also in [m], with the center of rotation for one of the gears being located at coordinates (-256.153, 249.956, 49.9558) meters. Basically it is very likely that this scale discrepancy is causing you some trouble. Hope this helps.
  2. If I also may add - it might also be that there was a gross error during pre-processing resulting in excessive overlapping particles in a certain location. There is a tool in SimLab which allows you to check "duplicate particles".
  3. So, looking at your log and .cfg - I cannot really see anything wrong. The only thing that strikes me is that your reference velocity (ref_vel) is 0.1 m/s, which could be a tad-bit too low, but I assume that a draining fluid could accelerate to faster than that under free fall. Try setting the speed to 0.5 m/s and see what happens. Additionally to the above conservative measure, you can try to ramp up the gravity a bit more slowly by setting the: t_damp_bodyforce_end 0.1 ; (instead of 0.01) in the domain parameters. That might help stabilize things a bit. Finally, as a last resort, for these quasi-hydro-static type of problems, using the RIEMANN interaction scheme would probably be beneficial as it is more diffusive and would certainly smooth things out. In order to do so, you need to set in the simulation parameters: adhesionmodel true freesurface true transportvelocity false surften_model ADAMI energy_transport false viscTempCoupling false dt_factor 1.0 maxitsteps 1000000000 operationMode NORMAL interactionscheme RIEMANN MLS_thres 0.97 APD_coeff 0.001 RM_freq_rho_reinit 20 RM_rho_filtering INSTANT damping_type LINEAR and in the phase parameters for oil/air: phase { name Oil type FLUID rho_0 842.0 dyn_visc 0.0463 surf_ten 0.03 print_info true print_phase true rho_compr 0.005 rm_beta 3.0 rm_rho_theta 1.e7 } phase { name Air type FLUID rho_0 1.2 dyn_visc 1.800000E-5 surf_ten 0.03 print_info true print_phase true rho_compr 0.005 rm_beta 3.0 rm_rho_theta 1.1 } The run will definitely be slower with these conservative settings, but you should get quality results, assuming sufficient resolution and no flaws on the geometry side. Hope this helps.
  4. Hi Linux34, There could be many reasons why would this occur, but material definition is most likely not related to the problem. For us to be able to provide better help, the log file of the simulation and the .cfg input file would be beneficial. Could you please share those here? Thanks, M
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