Dear FOAMers, I try to get
I try to get familiar with the twoPhaseEulerFoam-Solver in order to do bubbling fluidized bed simulations in the future. Therefore I started with the tutorial "bed2", but ran into various problems:
a) After some timesteps alpha becomes larger than the setting for alpha_max, finally leading to a blown-up alpha-equation.
DILUPBiCG: Solving for alpha, Initial residual = 0.00204016, Final residual = 6.59748e-11, No Iterations 4
Dispersed phase volume fraction = 0.275033 Min(alpha) = -3.08343e-18 Max(alpha) = 0.854645
DILUPBiCG: Solving for alpha, Initial residual = 9.44561e-05, Final residual = 3.20813e-12, No Iterations 4
Dispersed phase volume fraction = 0.275033 Min(alpha) = -3.08222e-18 Max(alpha) = 0.854609
GAMG: Solving for p, Initial residual = 0.00263152, Final residual = 6.91613e-09, No Iterations 27
time step continuity errors : sum local = 2.04471e-09, global = 2.39621e-10, cumulative = 3.95656e-07
DILUPBiCG: Solving for alpha, Initial residual = 0.00101853, Final residual = 5.98548e-11, No Iterations 4
Dispersed phase volume fraction = 0.275033 Min(alpha) = -3.08317e-18 Max(alpha) = 0.854606
DILUPBiCG: Solving for alpha, Initial residual = 8.03968e-05, Final residual = 3.01421e-11, No Iterations 167
Dispersed phase volume fraction = -5.04093 Min(alpha) = -25360.6 Max(alpha) = 8585.28
1 additional process aborted (not shown)
b) The bed expansion is not uniform and looks like a funnel.
c) There are "fallen vortices" of high theta values on the side walls of the freeboard.
Does anybody has some hints or best-practice guidelines for this kind of simulation with OF?
Many Thanks in advance.
Servus Matthias, there are
there are several threads about twoPhaseEulerFoam.
First one is quite general about the parameters in this solver
Second one is more about the issue of convergence problems regarding overpacking.
Hello Andreas, before posti
before posting I searched for related threads and also consulted the ones you mentioned already. Unfortunately I still have problems to set up a converging simulation.
Hello Matthias, tomorrow I
tomorrow I could send you one of my cases if you are then still intersted in them and provide me your email.
Hello Andreas, this would b
this would be very nice. Please use this email address:
Thanks a lot!
Unfortunately Andreas' case wa
Unfortunately Andreas' case was a bubble column and no fluidzed bed simulation.
So, are there some FOAMers with experience in using kinetic theory for gas-solid fluidzed beds?
|All times are GMT -4. The time now is 11:40.|