Hello:

I´m working in design the a low NOx natural gas burner with Fluent.

I'm investigating numerically flow characteristics, heat transfer and combustion process in a fired 2 MW boiler furnace. Now,I encounter some problems. The convergence is very difficult.

Anybody has some advices for me? Thanks,

Jorge

In general, the convergence is one of major problem for CFD simulation, especially for combustion, multri-phase and so on. Following tips might be helpful to you.

1) Mesh skewness affects convergence behavior for most flow simulation, especially for combustion simulation.

2) Under-relaxation parameters frequently affect convergence behavior. For example, Fluent's default setting for species under-relaxation is 1.0. This value is not good for most combustion simulation. Set them as lower value(e.g., 0.8~0.9 or ...).

3) Enthalpy is very difficult to converge. Check your mesh skewness and adjust under-relaxation by trial & error. I usually use 0.8~0.95 for enthalpy under-relaxation.

Sincerely, Jinwook

A) In addition to Jin, don't try to consider everything in the first Place B) Proceed with step by step: laminar, 2d, low flow rate... DC

hi dear friend

I am wroking on modeling of nozzle mixing gas burner we can share our problems and our developments

if agree to cooperate togather , I will be very happy .

kind regards shahriar .

[sudhir]

Hi all
I am a Undergraduate student of mechanical engineering. I am working on a new Design of natural gas burner for domestic applications and simulating this model in CFX so i will be thankful if you could provide me some data and text of your research.My Email Id is sudhir.sharma.mec07@itbhu.ac.in