I am simulating the bubble motion using NS equations in COMSOL 5.3a, but the equations cannot be converged. It would be grateful, if someone point out the mistakes in the simulations. The attached is COMSOL simulation file. Thanks.
https://www.sciencedirect.com/search?qs=Non%20linear%20equations%20in%20COMSOL&show=25&sortBy=relevance
hi my friend
probably your model is highly nonlinear. This is often the case in for instance mass transport models with fast reactions. Try to cancel some known nonlinearity in the problem and gently ramp it up with the parametric solver. For example, Stationary models with high reaction rates (high Ri), or more generally, large source terms, may result in convergence problems. You can for instance get error messages such as "No convergence, even when using the minimum damping factor", "NaN repeatedly found in solution", or "Error: Failed to find a solution".
OR
Your boundary conditions are inconsistent, either with each other or with your initial guess. Check your equation system and boundary conditions.
yes brother. I found the problem is my weak boundary conditions, which i cannot implement. I need to implement "weak constraints" on the air liquid interface (elliptical shape).I really do not know how to implement "weak constraints" in this case. I am attaching my other mph file with weak constraints. Please, you check its implementation. your help will be appreciated Thank you.
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