dsmcFoam freezing during run
I am facing a weird error.
I implemented another BinaryCollisionModel to the dsmcSolver in order to run simulations with the VSS-Model.
I am simulating a 1000nm long cube, which is a highly porous structure. On the one side is an inlet, the four long sides of the cube are a cyclic boundary condition and on the far end of the cube is a reflecting wall. Inside the cube are a lot of particles which were cutted out with snappy Hex Mesh in order to generate a highly porous structure.
Volume is filled with 1 atm of O2, the inflow has the same number density but with 1 % CO and 99 % of O2.
Everytime I run the case its freezing at 2.005e-08s of simulated time. The output simply stops after the inflow of the particles (after the inflow comes the particles movement routine and then the calculation of the collisions).
As i dont have a debug version of OF installed I made marks into the code to find out whats happening and I get stuck in the "particle::trackToFace" routine in the first loop:
I didn't look closely enough to the code do identify what the routine does exactly. I am pretty sure that it doesn't have anything to do with me playing around with the collisionModels because the applied changes are minor!
I'm working with OF-Version 2.1.1. but the dsmc library I am using comes from OF-201..
Apparently the error is also occuring when using OF201, a friend told me he was facing the same error in OF201 when simulating the same structure as I do.
It always occurs at the same time and I am pretty sure that my random generator is always producing the exact same sequence of pseudo-random numbers (running dsmcInitialise twice results in the exact same positions of generated parcels...) DsmcCloud uses a static number for initialising rndGen which is (971501 + 1526 * processorNumber). Is it usual that always the same number sequence is generated when the seed is the same? If yes, why not use a different number as seed, timestamp, etc?
So - back to my main question: Anybody ever faced freezing in dsmcFoam or has enough insides into the code of trackToFace to tell me what could possibly go wrong?
Would be very grateful, thanks in advance!
I am also facing exactly the same problem. It looks very much like a dead loop in the code but I haven't figured out yet. If what you found is correct, then I know the trackToFace loop searches for the face/boundary that the particle trajectory is intersected by, until the remaining trajectory is small enough to be neglected.
I will continue look into that and post here any new progress.
I stumpled upon a similar problem. Not with dsmcFoam, but with some other lagrangian calculations. This thread helped me a lot, especially the changes supposed in post #7:
Maybe it is of interest for you two.
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