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#1 |
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Hi, I'm trying to model an injection for a DI engine. My problem is that all my calculations diverge after roughly 1° after the beginning of the injection. The 'info' file indicates : "equation of state imbalance...". My questions are :
- Is the cell size very important? (my smallest cells are really small, but my time step is smaller than 1e-6 second...). - Which subroutines do I have to use, except newxyz (for my moving mesh), initfi and dropro? - 'MARS' differencig schemes (with bf = 0.5) is it adapted? - Is there any 'magic' switches to turn on or some Real Constants to supply? Thanks for yours responses. |
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#2 |
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There can be more problems that can cause the divergence. The mesh size is important, indeed. The CFL of the flow should be around 1 (at least in the critical regions); the Courant number for the droplets? how about this?(should be well below 1) the void_fraction/cell_volume ratio shoud be below 0.4;
(1) is the case with moving mesh running smoothly without droplets? (2) is the case running without moving the mesh and with droplets? (3) if it diverges, go for upwind first. try to rise the residual tolerance, more relax (4) try to turn off some enhencment of your model, go for basics first. I never met such a message yet, so just guessing ![]() matej |
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