Type of issue
solver crash, solver non-convergence
Description
Hello everyone, I built a very simple fluidized bed reactor to simulate coal (or sludge) combustion. Everything is okay in the initial phase of the simulation, but the solver crashed at 1.51s, and the error message is:
I have searched the forum for similar issues:
but the problem persisted as well.
I don’t know if the error is caused by reaction rate parameters in usr_rates_des.f, which I set randomly.
I’ve seen this “Unable to match particles crossing processor boundaries” before but was not able to get to the bottom of it.
Two observations:
It may be due to particles leaving the domain - velocities too high or wall stiffness too low.
It may depend on the number of nodes used. A previous case I investigated failed with 8 DMP nodes but succeeded with any other number. Experiment with the domain decomposition and see if that makes any difference.
Try searching the forum for PARCROSS and you will see previous reports of similar issues.
Hello Charles, I was on a business trip recently, so I’m sorry for not replying to you in time. Thanks for your suggestions, and I will try to modify the DMP nodes.
In my case, this problem occurs if the restitution coefficient of the particle is set too small, such as 0.5. If the restitution coefficient is set to 0.9, the problem will disappear. It’s very confusing.
Please try to increase the spring stiffness and frequency of Neighbor search to see if this helps.
I found that if the restitution coefficient of the particle is small, like 0.5, the particle will be pushed to the other side of the wall by other particles, even if the Young’s modulus reaches 0.1GPa.
