Hello out there. If one has to choose between FLUENT and FLOTRAN. Which code is best for external flow, and why? (mostly incompressible, turbulent flow) Peo

(1). Define your mostly incompressible, turbulent flow first. So that you and others can understand the problem. (2). Contact code vendors, and ask them to comment on your problem, to see whether they can give you a reasonable solution. (3). Send the vendors your problem, and when the solution does come back, evaluate the results and make your own decision as to which one to use. (4). Without knowing the problem itself, and without seeing the result for the problem, the code names are just trade marks only (just like your name ).

"mostly incompressible, turbulent flow" means that I'm working with flow problems concerning submarines. At the moment I'm using FLUENT 5, and would like to know if someone knows if there are any big differenses between FLUENT and FLOTRAN. Sorry if I was unclear in my former message. Peo

If you are dealing with submerged bodies at typical submarine speeds, then you have an incompressible fluid (drop the mostly). Both codes will handle the physics of the problem. The differences then are found in ease of use (you'd have to try them both and see which you prefer) and cost (FLOWTRAN is an add-on to ANSYS, and is much less expensive than FLUENT if you're paying for ANSYS anyway).

i don't know if you've decided to eliminate other codes from consideration a priori but yo might want to check out others. i've used flotran (for internal flow problems) and i was not satisfied. also i can't comment on the types of turbulence models it uses. i assume you'd want a (very) high Re model. of course flotran comes as part of ansys so you get all the ansys capabilities as well. i've never used fluent but i guess you have experience with it. there are codes out there (commercial) specially designed for marine work so you might want to search around for something more specific to your field

Hi client,

It appears you've been using FLUENT 5 for a while for external aerodynamics. Do you have any difficulties using FLUENT 5 for you external flow applications ? FLUENT 5 has been successfully used by many many others and as such has a proven track-record in the area of external aerodynamics and hydrodynamics applications including ship and marine applications, such as surface ships and under-water bodies.

Please let me know if you need any help from us.