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-   -   Surfboard fin CAD models (http://www.cfd-online.com/Forums/fluent/124011-surfboard-fin-cad-models.html)

Bdew8556 September 25, 2013 23:25

Surfboard fin CAD models
 
Hi There fellow CFDers

Im trying to get my hands on a variety of surfboard fin cad models for a cfd thesis.
Ive got two from this website but was hoping for more.

Basically im trying to look at how base width and rake angle effect Cl and Cd coefficients.

Any help is much appreciated and wont be used in a commercial setting.

Cheers

Brett

Woodbuddha January 4, 2014 19:50

CAD Fin Models
 
Hi Brett,

Are you still progressing your research? I am very interested from a personal perspective on CFD modelling of fins. I am in the process of teaching myself fin design using BoardCAD and fin foil. These are open source packages and seem to be quite useful.

I would be very interested in your research particularly the CFD side of things. Will you be looking at OpenFOAM?

TK

Bdew8556 January 4, 2014 22:16

Hi TK,

No im not anymore, I submitted the thesis in november.
I found that over a large range of conditions the 3 fin thruster set up tends to work the best, which would make sense as its the industry main stay.
if you can figure out how to use some kind of CAD model to generate a lot of different fin models that would be fantastic. I found just finding CAD models to be the hardest part. I used FLUENT so the geometry files basically have to be solidworks files, which im hopeless with.
I would recommend investigating the CL and CD values with the different fin models, specifically in relation to base width and rake angle. theres a few industry thoughts that you could prove or disprove.
I wasnt looking at OpenFOAM no, i used FLUENT.
As it was a Masters thesis there was no need to re-invent the wheel so to speak, but it does provide a pretty comprehensive CFD study, it just lacks the kind of concrete conclusions i was hoping for.

Are you doing this for university or work?

Brett

Woodbuddha January 4, 2014 23:12

Hi Brett,

Thanks for the reply. My main area of interest in this topic is a personal one, not work or university related. I am a communications Engineer who enjoys all things surfing. There's a lot of speculation and opinions regarding fin profiles and configurations and I would like to do some informal testing of various fin shapes to confirm theories. I am very interested in elliptical shapes, mainly spitfire type shapes and NACA symmetrical foils. I am still getting up to speed on fluid dynamics and am doing quite a bit of reading at the moment on the subject. Also reading through some other work done by various individuals.

WRT CAD models for fins, I am by no means a CAD guru. I am limited to open source software so I've been investigating options in that space. I have seen BoardCAD used with Jython scripts to generate 3D models of fins so I'm interested in spending a bit more time on that. FinFoil is also showing promise as a user friendly fin CAD program but it is still under development and not quite there.

Apparently Swansea University has developed a user friendly Fin CAD program but it is not freely available.

I would very much like to read your thesis if that is at all possible. I am interested in your testing methodology and maybe adapting it to OpenFOAM. Again I don't have access to FLUENT so I'm limited to open source software.

Anyway, thanks again for the reply. Looking forward to hearing your thoughts.

TK

BTW, here's a link to my blog. I make wooden surfboards in my spare time.

http://www.thewoodbuddha.blogspot.com.au/

Bdew8556 January 5, 2014 00:27

TK,

Im happy to send you my thesis but its about 75 pages so its not a quick read.
Fluid dynamics is a very complicated field and there are certainly no easy answers. Infact the Navier stokes equations have still not been solved analytically for turbulent flow.
By Engineer do you mean you went to university or does that mean youre a technician sort of person? the term gets thrown around alot.
If youve got an advanced maths knowledge, mostly around PDEs then you could chip away at the knowledge. A good place to start is to familiarise yourself with the Navier stokes equations, start with 1D and then expand that to 2,3D when youre comfortable, these are the fundamental equations for fluid dynamics, CFD turns them into discrete data and crunches the numbers for us.

whats your email address? this forum only allows a max of 97.7kb for attachments.

Brett

Woodbuddha January 5, 2014 02:25

Thanks Brett.

My email address is woodbuddha1@gmail.com

Looking forward to reading your thesis.

I went to university at QUT but I also trained as an electronics technician.

Thanks again.

TK

ben123 April 6, 2014 11:44

Cfd
 
Hi Brett,

I am also interested in CFD analysis of a surfboard fin, Im currently writing my dissertation on a new concept surf fin. Was just wondering whether you would send me your thesis too.

Thanks

Ben

Woodbuddha April 6, 2014 20:58

Quote:

Originally Posted by ben123 (Post 484176)
Hi Brett,

I'm currently writing my dissertation on a new concept surf fin.

Hi Ben,

A new concept surf fin? Can you elaborate? What CFD software will you be using for your analysis?

TK

Bdew8556 April 6, 2014 22:23

Hi Ben,

Yeah no worries, whats your email and ill send it through?
At a guess id say youre working on a hydrofoil fin? ive seen some sketches of those, looks promising.

Brett

ben123 April 8, 2014 10:23

Dissertation
 
Hi Brett,

my email is: ben@apvl.co.uk
Not quite a hydrofoil i have taken an idea from formula 1 and added a feature to fin so far looks really promising.

TK- im using CFX in ANSYS workbench would love to elaborate, once my dissertation is done and i have patented my idea ill post up some details and pics.

Thanks

Ben


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