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-   -   Evaluating CFD Packages for Hydrodynamic Drag in Underwater Vehicles (https://www.cfd-online.com/Forums/main/86535-evaluating-cfd-packages-hydrodynamic-drag-underwater-vehicles.html)

Dundee March 24, 2011 22:08

Evaluating CFD Packages for Hydrodynamic Drag in Underwater Vehicles
 
I'm a long time off-and-on user of SolidWorks Flow (FloWorks). I've used the software to calculate fluid drag in steady state flow for fully submerged underwater objects, vehicles, structures etc. Although the user interface has always been awkward and seemingly devoid of any "focus group" input whenever layout design was considered, the software does give results such as XYZ axis drag force, moment force and flow stream visualizaton ribbons, etc. all on a mid-level PC workstation. Pretty nice...

I'm now helping a new client select a CFD tool and was curious to know what others think of Solidworks Flow ($14K) for this purpose. Are there other packages worth considering and what significant advantages do they offer over SW Flow? For example I demo'd CFDesign ($21K-$30K) several years ago and loved the user interface and work flow - so intuitive and easy to use. Clearly the CF Design developers were in tune with the needs and desires of the end user in regards to setting up the simulations. I'm also looking at ANSYS CFD Flow ($30K) and CD Adapco STAR CCM+ however the they are very $$$ and I don't know what advantages they offer for what we're looking to do. Regarding accuracy, since the ocean is filled with so many variables to begin with, we'd be very happy with an accuracy of +/- 10 to 15%.

Almost forgot... The extra credit functionality is for the software to be used for propeller design. Both Solidworks Flow and CF Design ($30K Motion version) claim to to do this so some degree. We'd want to know hydrodynamic thrust (force) for a given design rotating at a given speed, along with cavitation detection. Ths is not a requirement of the software but would be a really nice feature, although I imagine processor requirements would increase considerably.

Your comments please...

Thanks,
Chris

sail March 25, 2011 13:05

Quote:

Originally Posted by Dundee (Post 300982)
I'm a long time off-and-on user of SolidWorks Flow (FloWorks). I've used the software to calculate fluid drag in steady state flow for fully submerged underwater objects, vehicles, structures etc. Although the user interface has always been awkward and seemingly devoid of any "focus group" input whenever layout design was considered, the software does give results such as XYZ axis drag force, moment force and flow stream visualizaton ribbons, etc. all on a mid-level PC workstation. Pretty nice...

I'm now helping a new client select a CFD tool and was curious to know what others think of Solidworks Flow ($14K) for this purpose. Are there other packages worth considering and what significant advantages do they offer over SW Flow? For example I demo'd CFDesign ($21K-$30K) several years ago and loved the user interface and work flow - so intuitive and easy to use. Clearly the CF Design developers were in tune with the needs and desires of the end user in regards to setting up the simulations. I'm also looking at ANSYS CFD Flow ($30K) and CD Adapco STAR CCM+ however the they are very $$$ and I don't know what advantages they offer for what we're looking to do. Regarding accuracy, since the ocean is filled with so many variables to begin with, we'd be very happy with an accuracy of +/- 10 to 15%.

Almost forgot... The extra credit functionality is for the software to be used for propeller design. Both Solidworks Flow and CF Design ($30K Motion version) claim to to do this so some degree. We'd want to know hydrodynamic thrust (force) for a given design rotating at a given speed, along with cavitation detection. Ths is not a requirement of the software but would be a really nice feature, although I imagine processor requirements would increase considerably.

Your comments please...

Thanks,
Chris

i would recommend giving a simple case of which you have experimental data to every vendor and see what results they get.

you should not use publicized material to perform a true blind test.

i've used both starccm+ and fluent with profit and only get to have a fast overview of swFlow, but i found it very immature and toyish, but i'm far from having a real experience on it, so i might be wrong.

have you considered using openfoam? maybe you can invest your money to have a nice gui and becnhmark set-ups done by some professional.

Thouelfaqar March 26, 2011 09:21

In the name of Allah the most merciful and gracious . Peace and Prayers upon prophet Mohamed and all prophets
Dear colleagues,
Hope you are all fine.
I really don't know where to post this message so that those to whom it may be useful can easily find it.

Thanks to God, we managed to get some COMSOL tutorials working that are closely related to the marine engineering field. I am attaching links to them along with educational videos
There is an explanation in Arabic but it is not necessary as the videos themselves are, God's willing, self-explanatory. I expect they may be useful to someone starting learning CFD simulation.


http://rapidshare.com/files/45432486...rial_babies.7z
http://rapidshare.com/files/44716699...od_ISA.swf.rar
http://rapidshare.com/files/45436182...t1_good.swf.7z
http://rapidshare.com/files/44717122...model_files.7z
http://rapidshare.com/files/45433253...not_working.7z


Since simulation can be used together with artificial neural networks (ANNs) to optimize hydrodynamic design, I am attaching also some ANN educational videos. Maybe some one would find them useful
If you have any questions, please feel free to ask us either here at the forum or at our group email
mashaheedanfsa@gmail.com


http://rapidshare.com/files/44854107...lah_ANN_MLP.7z
http://rapidshare.com/files/44823740...ah_ANN_NGML.7z
http://rapidshare.com/files/44852069...NN_example1.7z
http://rapidshare.com/files/44834373...NN_example2.7z
http://rapidshare.com/files/44845668...mple3_parta.7z
http://rapidshare.com/files/44836034...mple3_partb.7z
http://rapidshare.com/files/44833258...mple3_partc.7z


//**THIS COMING ONE IS VERY IMPORTANT FOR EXAMPLE 3 CONCEPTUAL AND ERROR CORRECTIONS
http://rapidshare.com/files/44942722...working_now.7z

jchawner March 27, 2011 15:19

One of the most recent events in marine CFD was http://www.gothenburg2010.org/. Perhaps there's something on their web site (presentations, benchmarks) that can help you decide.

Sam-CFD December 5, 2011 07:31

Hi,

As far as I know, CFDesign doesn't offer any multiphase flow capability which I perceive will be in your problem.

If you are intending to include propeller, cavitation effects, etc., a cheaper and yet comprehensive tool would be Star CCM+. They might also offer you decent support in executing your project.

ANSYS CFD is quite comprehensive but may not be necessary.


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