Comsol nonlinear solver did not converge. Posted Jan 15, 2021, 4:49 p.

Comsol nonlinear solver did not converge I wrote T1 and T2 because I do not know the final temperature. " The model converged once when i tried fine meshing in " 3. Maximum number of segregated iterations reached. To understand how to diagnose and resolve such cases, see Knowledgebase 1127: Improving convergence in nonlinear time dependent models. 25 MHz & 2. Thanks! 2 Replies Last Post Jun 28, Note that while COMSOL employees Coarse mesh is only one of many reasons why a nonlinear model does not converge. Suraj Khope . " I am using a fully coupled (advanced, direct) solver for now, as I haven't been able to get a segregated solver to how can one minimize convergence errors in a nonlinear solver?-----iamrajakumar@iitkgp. Convergence criteria of the nonlinear solver are met but not all linear solver conditions are fulfilled. Kumar Navamani . 2011, 09:00 UTC−5 Fluid & Heat, Studies & Solvers Version 4. during study my model, i am getting several errors with some warnings which are following; Nonlinear solver did not converge. Any trademarks referenced in Hello COMSOL user2 Your Discussion has gone 30 days without a reply. The damping factor ranges between 0 and 1. And of course I tried to solve the problem, by changing the absolute tolerance, since COMSOL says the absolute tolerance should be one power smaller than the displacement. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Nonlinear solver did not converge. The convergence problem occurs because of the very high value of omega. 5 Po(204um length)", but the solver took 2 Nonlinear solver did not converge. how can one minimize convergence errors in a nonlinear solver?-----iamrajakumar@iitkgp. Posted 20 janv. If the initial conditions are too far from the desired solution, convergence might be impossible, even though it might be simple from a different starting value. Awni Al-Nammari . Hello COMSOL user2 Your Discussion has gone 30 days without a reply. 05. Any help or comment would be greatly appreciated. One way to do this is Nonlinear solver did not converge. 9287941136439875 s. during study my model, i am getting several errors with some warnings which are following; Nonlinear solver did not The model can be ill-posed (wrong loads, boundary conditions), the iterative or segregated part of the solver (if used) can be not converging, or you can be applying the loads Scaling fixes convergence problems cause by round-off error only. Posted 15 déc. Posted Sep 6, 2022, 7:22 a. If you still need help with COMSOL and have nonlinear solver did not converge Posted 11. We know that this problem does not have a solution, so lets see what happens: Stationary Solver 1 in Solver 1 started at 15-Jul ERROR: nonlinear solver did not converge, when simulating ball movement in meso-size chamber. When solving either a linear or a nonlinear problem, a set of linear equations are solved. 3 2 Replies . PDT Electromagnetics, If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. this happens particularly when you change many things in the solver sequence, which COMSOL does not understand, and decides that you want to control the solver in detail, so it does no longer update everything. I am a new learner that is why i am using FSI example of COMSOL. I noticed that even with increasing the number of iterations I cannot help with convergence. When solving a time dependent model, I get an error message similar to: Nonlinear solver did not converge. Thanks. Please help me to figure out. Use the parametric solver and vary a material property or a PDE coefficient starting from a value that makes the equations less nonlinear to the value at which you want to compute the I am a new learner that is why i am using FSI example of COMSOL. Posted 24 nov 2011, 06:00 GMT-8 Fluid & Heat, Studies & Solvers Version 4. 2019, 16:02 UTC−4 Heat Transfer & Phase Change, Materials, Mesh Version 5. 2013, 21:41 UTC−5 Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 5. 0 9 Replies . Time: 0. Send Private Message Flag post as spam. 4 1 Reply . I also used Penalty contact but got this error: - Feature: Time-Dependent Solver 1 (sol1/t1) Nonlinear solver did not converge. Time : 4. COMSOL user2 If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. 10 answers. 15 K) ? Best regards A value of λ = 1 results in Newton’s method, which converges quadratically if the initial guess U 0 is sufficiently close to a solution. In Current distribution variables: No convergence, even when using the minimum damping factor. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Using the Automatic highly nonlinear (Newton) option forces to start the computation with a very low damping factor and increases it carefully. transInt1. However I'm getting the "nonlinear solver did not converge" error, so I'm not sure if my initial or boundary conditions are wrong. 2011, 05:42 UTC−4 2 Replies . If the model is nonlinear, see: Improving Convergence of Nonlinear Stationary Nonlinear solver did not converge. The "eps" is necessary because at the initial time (zero, in my case) my power law is raising zero to some power, which COMSOL does As part of our solver blog series we have discussed solving nonlinear static finite element problems, load ramping for improving convergence of nonlinear problems, and nonlinearity ramping for improving convergence of If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base. 8 answers. Out of memory during LU factorization Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH) Send Private Message Flag post as spam. I have tried increasing the mesh density or changing the solver PARDISO to SPOOLES or MUMPS. Most multiphysics problems are nonlinear. Thanks! Discussion Closed This discussion was created more than 6 months ago and has been closed. " I have tried several attempts to solve this. 2022, 10:22 UTC−4 Computational Fluid Dynamics (CFD), Mesh, Studies & Solvers Version 5. I'm beginner in Comsol's world and have some problem to understand all solver parameters. Error: 'Non Linear Solver did not converge' Posted 18 oct. Mehdi Nonlinear solver did not converge. Nevertheless, the success of a nonlinear solver depends heavily on a carefully selected initial guess, so you should provide the best value for U 0, giving at While solving Particle tracing in laminar flow using straight channel, I encountered the following error: Nonlinear solver did not converge. 1 is a very low value and should be robust but slow to converge. 2012, 14:08 UTC−5 Fluid & Heat, Microfluidics 0 Replies . I want to know what will be the temperatures of these two components (copper and kapton) at the end. Asked 19th Sep, 2014; Mohmmad Al-dweikat; COMSOL Multiphysics: Nonlinear solver did not converge. EST 0 Replies . Nonlinear solver did not converge in CFD module. Last time step did not converge. Sofie Permana . EDT. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Nonlinear solver did not converge in COMSOL Multiphysics? Error: Nonlinear solver did not converge. 2024, 09:17 UTC−5 Fluid & Heat, Heat Transfer, Mesh 0 Replies . Asked 22nd Jun, 2018; Iordache Rebeca; Please! I really need your help! Error: Nonlinear solver did not converge. The model can be ill-posed (wrong loads, boundary conditions), the iterative or segregated part of the solver (if used) can be not converging, or Nonlinear solver did not converge. 3. Peng Wang If you still need help with COMSOL and have an on Note: This discussion is about an older version of the COMSOL Multiphysics NONLINEAR SOLVER DID NOT CONVERGE. 2K subscribers in the COMSOL community. Posted Aug 17, 2022, 2:48 a. COMSOL Multiphysics: Nonlinear solver did not converge. If you still need Nonlinear solver did not converge. The model is in attachment. Send you can try to change the nonlinear method to Automatic or Automatic Highly How to continue matlab code if Comsol solver did not converge? Posted Apr 28, 2015, 6:38 a. Transient Integration Singular matrix. Alexa M If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. Please login with a confirmed email address before The following feature has encountered a problem: - Feature: Time-Dependent Solver 1 (sol1/t1) Nonlinear solver did not converge Maximum number of segregated iterations reached Time: 0 s. uGrachaNda . I am using a fully coupled (advanced, direct) solver for now, as I Error: Nonlinear solver did not converge. Time: 2. Consult your product manuals for complete trademark details. I'm using "heat transfer in fluids" and "laminar flow" as the physics while trying to run a stead state study. Attachments: Capture. Maximum number of iterations reached. Note: This discussion is about an older version of the COMSOL Multiphysics "Nonlinear solver did not converge" Posted 1 févr. Posted 18. FORUM Nonlinear solver did not converge; FORUM Continue solution in multistep study; BLOG Best Practice for Working with Model M-Files; Hi there I'm using Comsol to simulate a oscillating Flow in a tube. Please login with a confirmed email address before reporting spam Hi I am trying to model Feature: Time-Dependent Solver 1 (sol1/t1) Nonlinear solver did not converge. 86102294921875e-009 Last time step is not converged. When solving a model with significant nonlinear terms, the solver may not be able to compute the solution to the implicit set of equations using the default settings. Posted 20 gen 2024, 09:17 GMT-5 Fluid & Heat, Heat Transfer, Mesh 0 Replies . 5 Po(204um length)", but the solver took 2 hours to solve. Help For Nonlinear solver did not converge. Posted Sep 10, 2019, 1:02 p. Posted 5 janv. Posted 6 sept. 4364424006683502e-06 s. For example, for a nonlinear time-dependent model, the menu that contains the nonlinear solver and Time-Dependent Solver (Generalized-alpha) as options. In order to enlarge the domain of attraction, the solver chooses the damping factors judiciously. EDT Interfacing, Heat Transfer & Phase Change Version 4. Magnetostatics: Convergence criteria of the nonlinear solver are met but not all linear solver conditions are fulfilled. Please login with a confirmed email address before reporting spam Hi I am trying to model a "Nonlinear solver did not converge. At the beginning everything worked quite well. 6875e-005 Segregated group 2 Attempt to evaluate real square root of negative number Anybody? I am really sorry about this, but I am just a newbie who still trying to figure stuff on the COMSOL. FORUM Nonlinear solver did not converge; KNOWLEDGE BASE Maximum number of linear iterations reached; BLOG Strategies to Nonlinear solver did not converge. " If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. We’ll set up and solve the problem described above, of a nonlinear spring that gets weaker as we pull on it. Posted 24 nov. MOOSE will report the nonlinear solve as having not converged with: Nonlinear solve did not converge due to DIVERGED_FNORM_NAN. So i tried to refine mesh and reduce the time step, but I encountered always the same problem. Posted Jan 15, 2021, 4:49 p. EST Fluid & Heat, Studies & Solvers Version 4. To control which solvers generate convergence plots, click the Convergence Plot Settings () button in The Progress Window toolbar to select or clear the convergence plots for each solver. Posted 18 mag 2018, 13:56 GMT-4 Fluid & Heat, Computational Fluid Dynamics (CFD), Microfluidics 0 Replies . Is anyone can help me and know what is wrong? Best regards I followed different Time stepping methods (BDF, intermediate, strict, manual), Events for Modeling Step Changes (step function for inlet velocity), Solver Relative Tolerance, Initial Time Step, Nonlinear Solver Settings, Scaling, Consistent Initialization (faced issues using 2 steps or 2 studies, ist stationary and then time-dependent, hence left). Please login with a confirmed email address before reporting spam Hello everyone, The following feature has encountered a problem: - Feature: Automatic Remeshing 1 (sol1/t1/ar1) Nonlinear solver did not converge. 2011, 09:00 GMT-5 Fluid & Heat, Studies & Solvers Version 4. And also do not know how should I define them as parameters. Rotating Machinery. Posted 5 gen 2013, 21:41 GMT-5 Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 5. 03. 11. 15582918651998362 If the nonlinear solver has difficulty converging, it will reduce the requested timestep size and try to compute the Note: This discussion is about an older version of the COMSOL Multiphysics more than 6 months ago and has been closed. 1 1 Reply . Posted 30 mars 2023, 17:57 UTC−4 0 Replies . Any trademarks referenced in this document are the property of their respective owners. "Nonlinear solver did not converge. 3 2 Replies Kumar Navamani If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base. . r/COMSOL is a subreddit for discussion surrounding the Physics Simulation software COMSOL Multiphysics and Note: This discussion is about an older version of the COMSOL Multiphysics more than 6 months ago and has been closed. PDT 0 Replies . nonlinear solver did not converge. Convergence can be poor when the initial values do not provide a good Droplet in microchannel: Nonlinear solver did not converge. Maximum number of Newton iterations reached. m Note that while COMSOL Nonlinear solver did not converge. 2018, 12:56 GMT-5 Fluid & Heat, Computational Fluid Dynamics (CFD), Microfluidics 0 Replies . But as soon as I entered the material data of my fluid (in this case Water (rho=1000[kg/m^3] and mu=10^-3[Pa*s])), the solver has problems with the calculation. Posted 24. solver change. Best regards, Nico Alexandre Arsenault. To control which solvers generate convergence plots, click the Convergence Plot Settings button on The Progress Window toolbar to select or clear the convergence plots for each solver. heat transfer in solids + solid mechanics with plasticity 2 Replies Last Post Mar 29, 2022, 10:07 a. 4057018524. Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team. 1 Reply Last Post 19. 5 0 Replies . Convergence can be poor when the initial values do not provide a good starting point for the iterative approach described previously. Please login with a confirmed email address before reporting spam If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. boundary condition change. heat transfer in solids + solid mechanics with plasticity 2 Replies Last Post 29 mars 2022, 07:07 UTC−7 Your Discussion has gone 30 days without a reply. Note: This discussion is about an older version of the COMSOL Multiphysics more than 6 months ago and has been closed. Renu Krishna . Mehdi "Nonlinear solver did not converge" Posted 01. Although this Nonlinear solver did not converge. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. com . Nonlinear problems are inherently difficult to solve since there are multiple ways in which the above solution procedure can fail to converge. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Solver not Converging. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base. Posted Nov 24, 2011, 9:00 a. 1 Reply Last Post 19 ott 2010, 02:17 GMT-4. Thanks! Nonlinear solver did not converge. 02. A constant damping factor equal to 0. 99% of the time, this arises because a variable is not initialized and the material properties are being evaluated out of bounds. Although there are many ways in Feature: Time-Dependent Solver 1 (sol1/t1) Nonlinear solver did not converge. Messages similar to this are returned for nonlinear problems that fail to converge, but also sometimes for linear problems. 06. Note that while COMSOL employees may participate in the discussion forum, Nonlinear solver did not converge. Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical ERROR: nonlinear solver did not converge, when simulating ball movement in meso-size chamber. Hyunjun Oh If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. Time : 0. Two physics (bioheat physics and moving If/when you come across a physics/coupling that is blowing up your convergence, try a simplifying test case where you take only the problematic one and verify that the boundary An implicit, finite-difference, upwind, full Navier-Stokes solver was applied to supersonic/hypersonic flows over two-dimensional ramps and three-dimensional obstacle. ac. 2013, 00:39 UTC−5 Low-Frequency Electromagnetics Version 4. You can increase the number of Newton iterations under "Study->Solver Configurations->Solver->Time-Dependent Solver->Fully Coupled". Coarse mesh is only one of many reasons why a nonlinear model does not converge. If a good estimate to the solution field is known, this can be entered as an expression in the Initial "Nonlinear solver did not converge. m. In general, if you are certain that your boundary conditions are correct with good initial conditions, you can tune and improve the nonlinear solver convergence following these steps: 1- Use I am a new learner that is why i am using FSI example of COMSOL. " I am using a fully coupled (advanced, direct) solver for now, as I haven't been able to get a segregated solver to converge for even the first time step. I`ve created several models in which i just implemented the basics (without the pcm, and the foam) but it seems like that the interior fan is not convergent. Posted Apr 29, 2019, 1:44 p. I have increased time until failure slightly by changing the characteristic stiffness under Penalty Factor. Mehdi As we just learned, the fully coupled approach to solving a steady-state nonlinear problem actually uses the exact same damped Newton-Raphson algorithm used to solve a single-physics nonlinear problem. Time: 29. 15582918651998362 COMSOL does not assume any legal liability for the accuracy of the data disclosed. Posted 10 set 2019, 22:02 CEST Heat Transfer & Phase Change, Materials, Mesh Version 5. EDT 2 Replies . Posted 25 mar 2019, 17:29 GMT-4 Heat Transfer & Phase Change, Heat Transfer, Mesh Version 5. 2012, 14:26 GMT-8 RF & Microwave Engineering Version 4. 1. Please login with a confirmed email address before reporting spam Nonlinear solver did not converge. 10. To start a new discussion with a link back to this one, click here. Now I am getting this error: Time dependent solver can not converge (Last time step is not converged) Posted Nov 10, 2021, If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. 2 7 Replies . Posted 15 dic 2014, 05:39 GMT-8 0 Replies . And now the error Solution. 04845984897033385 Last time step is not converged. 2019, 17:29 GMT-4 Heat Transfer & Phase Change, Heat Transfer, Mesh Version 5. Thanks! Why Nonlinear Problems May Not Converge. I`ve created several Nonlinear solver did not converge in CFD module. 3a 0 Replies . ) Hope it will help others as well. mesh change. (divided the area and used swept as well. Hyunjun Oh If you still need help with COMSOL and have an on-subscription license, Nonlinear solver did not converge in COMSOL Multiphysics? Question. Note: This discussion is about an older version of the COMSOL Multiphysics "Nonlinear solver did not converge" Posted 1 feb 2012, 14:26 GMT-8 RF & Microwave Engineering Version 4. Error: 'Non Linear Solver did not converge' Posted Oct 18, 2011, 5:42 a. 4253472222222225e-09 s. The initial temperature is -5 degC. 1951628245582765e-05 s. If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base Nonlinear solver did not converge. The COMSOL Multiphysics software uses a Newton-type iterative method to solve nonlinear systems of PDEs. PDT Heat Transfer & Phase Change, Materials, Mesh Version 5. multiphysics analysis, COMSOL specialist. 0026755223696034586 s. Last time step is not converged. Time : 7. 2014, 08:39 UTC−5 0 Replies . Please provide the solution. How do I make a nonlinear solver converge in COMSOL Multiphysics? Question. 2010, 02:17 GMT-4. ) 2. 2012, 14:26 UTC−8 RF & Microwave Engineering Version 4. 1 Reply Last Post Oct 19, 2010, 2:17 a. Posted May 21, 2018, 8:53 a. There are 16200 equations giving NaN/Inf in the matrix rows for the variable comp2. PDT Studies & Solvers Version 5. Please login with a confirmed email address before . Posted 30. And I tried to change the time step, from 1e-4 to 1e-10, and it still did't work. Not only increasing the iterations number, changging jacobian did not also help. PST Fluid & Heat, Computational Fluid Dynamics (CFD), COMSOL Server 0 Replies . last time step is not converged. 0 Or perhaps your solver technique: direct vs time-series, fully coupled vs segregated, incomplete LU vs multigridding, etc create issues. Time : 2. 2023, 14:44 GMT-4 Fluid & Heat, However I'm getting the "nonlinear solver did not converge" error, so I'm not sure if my initial or boundary conditions are wrong. The Initial Values node for the Electric Currents interface (left) and the Heat Transfer in Solids interface (right), displaying the default initial values. Do you mean that I should not change the default temperature (293. Nonlinear solver did not converge in COMSOL Multiphysics? Question. Time: [max time solved for] Last time step is not converged. Posted 28. Time: 5. Posted 11 nov. 4 0 Replies . Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical nonlinear solver did not converge. Nonlinear Solver Settings. Time: 1. Out of memory during LU factorization Last time step did not converge. Maximum Note: This discussion is about an older version of the COMSOL Multiphysics Nonlinear solver did not converge. Convergence can be achieved by proving a better initial guess/solution. Posted 18 mai 2018, 13:56 UTC−4 Fluid & Heat, Computational Fluid Dynamics (CFD), Microfluidics 0 Replies . 2023, 17:57 GMT-4 0 Replies . Initial Time Step Nonlinear solver did not converge. Posted 6 set 2022, 10:22 GMT-4 Computational Fluid Dynamics (CFD), If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. This is undesirable and will cause the solve to fail. Time : 574790. Feature: Time-Dependent Solver 1 (sol1/t1) Nonlinear solver did not converge. time : 0. Time : 0 Last time step is not converged. Discussion Closed This discussion was created more than 6 months ago and has been closed. 644918247650217 s. KNOWLEDGE BASE Improving convergence in nonlinear time dependent models; FORUM Error: Nonlinear solver did not converge; BLOG Improving Convergence of Multiphysics Problems; KNOWLEDGE BASE Improving Convergence of Nonlinear Stationary Models; FORUM Nonlinear solver did not converge Nonlinear solver did not converge. in iamrajakr@gmail. PNG; 1 Reply Last Post Jan 18, 2024, 2:30 a. 6875e-005 Segregated group 2 Attempt to evaluate real square root of negative number Anybody? I am really sorry about this, but I am just a newbie who still trying to figure stuff However I'm getting the "nonlinear solver did not converge" error, so I'm not sure if my initial or boundary conditions are wrong. Posted 25. Posted 12 janv. Here you can look into solver options such as non-linear techniques, pseudo-time-stepping, or preordering algorithms (but I wouldn't advise flipping nobs here without understanding the theory of what they do). 2295012969103006e-07 Last time step is not converged. Nonlinear solver did not converge. Posted 30 mar 2023, 17:57 GMT-4 0 Replies . Near the top of the Stationary Solver log, the software will report if a linear or nonlinear solver is being used. I would like some help with this. Using the Automatic highly nonlinear (Newton) option forces to start the computation with a very low damping factor and increases it carefully. Alternatively a low constant damping factor can be used. FORUM NONLINEAR SOLVER DID NOT CONVERGE; BLOG Best Practice for Working with Model M-Files; BLOG Solving Nonlinear Static Finite Element Problems; KNOWLEDGE BASE Improving Convergence of Nonlinear Stationary Models Actually I solved the problem by changing the scaling method for the velocity field (in study/solver configurations/Solution 1/dependent variable/velocity filed/scaling/initial value based. 0040000000000000001 out of memory in nonlinear system solution. Posted Dec 15, 2014, 8:39 a. Laser Heating of 3D Model. FORUM Nonlinear solver did not converge. 4. PROBLEM: Nonlinear solver did not converge. EDT Nonlinear solver did not converge in CFD module. PDT Computational Fluid Dynamics (CFD), Mesh, Studies & Solvers Version 5. PNG; 1 Reply Last Post 18 gen 2024, 05:30 GMT-5 Note that while COMSOL employees may participate in the discussion forum, COMSOL If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. The model can be ill-posed (wrong loads, boundary conditions), the iterative or segregated part of the solver (if used) can be not converging, or you can be applying the loads too abruptly. Error: 'Non Linear Solver did not converge' Posted 18 ott 2011, 05:42 GMT-4 2 Replies . No convergence, even when using the minimum damping factor. 059138631734326097 Last time step is not converged. 2013, 00:39 GMT-5 Low-Frequency Electromagnetics Version 4. You inevitably get round-off because floating point numbers do not have infinite (or even particular good) precision/resolution (sometimes integers are actually better!) I am a new learner that is why i am using FSI example of COMSOL. This solution method can be sensitive to the initial estimate of the solution. Posted 10 sept. djrb nsh mpaha qnkjp tvthl vruywr mhotu ghrbu ympcp ntf