# Multiphase flow modeling

 Register Blogs Members List Search Today's Posts Mark Forums Read

 August 16, 2004, 10:14 Multiphase flow modeling #1 Paul Guest   Posts: n/a Hi guys, I want to use Fluent to simulate multiphase flow. My work may involve in significant model modifications usig UDF. I want to have a clue of how user-friendly to use UDF and how powerful they are. Your information is very helpful and highly appreciated. Paul

 August 16, 2004, 12:59 Re: Multiphase flow modeling #2 thomas Guest   Posts: n/a I would say handling udf for multiphase modelling isnt an easy thing. For me the only difficulty is to understand the notion of Thread and how to get them. There i am assuming you already know how to use udf for a single phase flow. About how powerful they are, it exist some limitation depending on how complex is you model modification ... let us know precisely what you want to do and me or somonelse will tell you what is up with your problem.

 August 16, 2004, 13:20 Re: Multiphase flow modeling #3 Paul Guest   Posts: n/a Thanks Thomas, Actually I don't have any experience of udf. I have been using CFX quite a lot and just tried several simple cases in FLuent. For example, if I want to simulate the entrained droplets interacting with the gas and liquid phases in stratified or annular flow. In this case, addition of a source or sink term both in the continuity and momentum equations is necessary to describe the mass and momentum gain or loss of the liquid phase, as well as the generation of the liquid droplet phase. Of course, it is not practical to tracking the individual droplets with the computer power till date. Also, the mass and momentum interchange coefficients should be functions of local flow parameters. Meanwhile it may also necessary to modify the drag force and lift force which are believed to be functions of local void fraction. I am well aware the model modification for this kind of work is extremely intensive. I want to get a feeling of the possibility of accomplishing this work using FLUENT.

 August 16, 2004, 14:22 Re: Multiphase flow modeling #4 thomas Guest   Posts: n/a Your problem seems to be manageable with fluent. Computing the mass and momentum interchange coefficients, drag and lift force functions of local flow parameters isnt a problem using fluent ... read carefully the documentation. The only difficulty i see is how you are gonna create the droplet generation. This cause a stratified flow or annular flow is relevent from teh OVF model when the a droplet tracking is relevant from the DPM model or euler euler model in certain case. All that depends on what you looking for in the end ... this will tell you what assumption to make and thus what model to use. Hope this help

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post magnounibo FLUENT 0 April 30, 2009 03:59 Paul CFX 0 August 16, 2004 10:07 A. Ataki FLUENT 1 November 10, 2003 05:46 Axel Rohde Main CFD Forum 1 November 19, 2001 13:19 HB &DS CFX 0 January 9, 2000 14:19

All times are GMT -4. The time now is 00:35.