Hi, all!
I am attempting to set up a CFD-DEM (CGP) to simulate fluidized bed heating particles, and used fluid viscosity UDF and particle_input.dat.
At the beginning, it can still calculate normally, but after ten minutes, it shows:“Warning from utilities_mod.f:169
Velocity exceeds limit: 80.000
in cell: I = 2 J = 7 K = 2
Epg = 0.71425 Ug = -3.3853 Vg = 81.593 Wg = -6.5223
To change the limit, adjust the scale factor MAX_INLET_VEL_FAC.” , then it stops and reports an error: "DT < DT_MIN. Recovery not possible!”
I tried to increase MAX_INLET_VEL_FAC to 2 or reduce the mesh size, respectively. This error appeared again. No error is reported when disable the energy equation.
Can anyone tell me what I was wrong? I really appreciate your help!
ReactionTest.zip (169.4 KB)
Hi - sorry this question slipped between the cracks. Have you found a solution?
Try searching the forum for MAX_INLET_VEL_FAC, this is a fairly common error and is typically due to poor mesh quality.
Oh, cgw, it’s just because the maximum time step is too large, changing it to 1.0e-4 and time step to 1.0e-5 will be OK.