thanks everybody : I have a problem . I want to calculate a reacting flow ,It is a reaction between potassium hydroxide solution and sulfur dioxide . if somebody can tell me how to upbuild the solution use FLUENT?? thank you .

is there somebody who can help me ???

Have you established that modelling a gas-liquid multiphase, heterogeneously reacting flow is best solved using computational fluid dynamics? Why is CFD ideal for this particular case? Have you cosidered lumped-parameter (or compartmental for that matter) modelling?

If so, then you can use FLUENT 4. The multiphase (gas-liquid) aspect can be modelled "plug-n-play" with the Eulerian-Eulerian multiphase model. To complicate matters, if you want to model the actual jet breakup of the SO2 stream then you'll require user-subroutines to model the multiple flow regimes and corresponding diameter changes. To model the heterogeneous reactions, you will require a couple of UDS's.

Contact your Fluent support person who will be able to direct you to the appropriate sample cases (ref: advanced multiphase training course).

thank you for your help. I use fluent because I want to see the phenomena of the stream field. I want to ask , if I only have fluent5.5 ,can I work out this problem? I found that defining so2 and water mixture is not difficult ,but I can't defining the solution of ca(oh)2 ,is this solid-liquid mixture?? I think it is not . can I use Prepdf to define a mixture of water and OH- to model that solution??

You could model the SO2 injection as discrete bubbles using the DPM model, providing the problem satisfies the constraints of the model (see Users Guide). As such, you can have the SO2 in the DPM (gas) phase reacting nicely with reactant in the liquid phase.

For the reactions, use eddy breakup (not finite-rate). PDF assumes "mixed-is-burnt" and may not be completely applicable to your case. Review the literature on theis for more info. Do you have experimental data on the reaction? You will likely need this to validate the reaction model since the reaction models are all based on gas-phase reactions (combustion).

How does Ca(OH)2 come into play? Is this a product or reactant? If the concn is very low, it would not be unreasonable to ignore the solids and modify the liquid phase properties instead.