Dear Experts, We are modeling coal combustion in a boiler using DPM. We are observing that at some point of iteration, all the convergence criteria are about to be satisfied, but If the simulation is run for some more iterations, the monitored temperatures and other variables start fluctuating and this fluctuations do not stop even for thousands of iterations. This does not allow us to freeze the runs. We are using second order discretization, k-epsilon model, and DO radiation model. Please suggest me your valuable suggestions.

Thanking you, With regards

Amit Katiysr

i'm pleased to know you,please help me to find the following: all files is required: data base,mesh,case,data and analysis file

What do u mean by "convergence criteria"? I hope not the default criteria used by Fluent... Your fluctuations could depend on the cell size utilized where partcicle tracking occurs: u need a very refined grid in those regions. How many particles are u tracking? If u stop the tracking, does the case converges? Or simply u're modelling an unstable (time depending) case. Have u tried to converge with a linear spatial discretization before trying with the parabolic method?

thomas

[maazulmosaid]

dear amit

please share your experience with us

what model you chooses?

thnx in advance

[ashishtonge]

hello sir
I am doing my m tech project in CFD simulation of coal gasification.In that i choose the entrainment flow reactor and graw a 3D geometry in design modular and did meshing,but i confuse in fluent i choose the
stsndard K-E model,species transport model,finite rate eddy dissipation turbulence chemistry model,i write reaction in reaction window.
my feed coal is in granular form when i used coal partical injection in coal inlet ,where i put my boundary condition(composition of coal) in coal inlet.
In boundary condition c(s) option not came for granular inlet composition. if you require any more information about my project please contact me on this email id- ashishtonge64@gmail.com
Please help me sir......