Issue with Pulsatile Flow Simulation in COMSOL (Failed to Find Consistent Initial Values)

Armel Jouel Sadio Takeng

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Hello everyone,

I am working on a simulation in COMSOL involving a deformable tube, and I am trying to apply a pulsatile flow by defining a velocity profile as follows: v₀ = 10 * sin(2πt).

However, when I run the simulation, I encounter the following error: "Failed to find consistent initial values. Last time step is not converged."

It is worth mentioning that the model works perfectly with a constant velocity, which suggests that the issue might be related to the introduction of time dependency or the initial conditions.

Do you have any advice on how to resolve this issue? Should I adjust the initial conditions, the time discretization, or other parameters? Thank you in advance for your help!


1 Reply Last Post Dec 13, 2024, 9:11 a.m. EST
Jeff Hiller COMSOL Employee

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Posted: 2 weeks ago Dec 13, 2024, 9:11 a.m. EST

Hello Armel,

One possibility is that to run the problem with a constant boundary velocity you set an initial velocity in the domain equal to that boundary velocity, so that everything was consistent and solved, but that when you changed the boundary velocity you forgot to change the initial velocity in the domain accordingly, hence introducing an inconsistency between boundary conditions and initial conditions.

This is only a guess. If that does not seem to be the issue, consider posting your mph file (after removing the mesh and solution to reduce the file size).

Best,

Jeff

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Jeff Hiller
Hello Armel, One possibility is that to run the problem with a constant boundary velocity you set an initial velocity in the domain equal to that boundary velocity, so that everything was consistent and solved, but that when you changed the boundary velocity you forgot to change the initial velocity in the domain accordingly, hence introducing an inconsistency between boundary conditions and initial conditions. This is only a guess. If that does not seem to be the issue, consider posting your mph file (after removing the mesh and solution to reduce the file size). Best, Jeff

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