CFD modelling - skiff

Danny Boy

New member
43
0
Danny Boy, that's a goergeous looking toy, but how in pete's name do you tack?

Cheers

Just sail with a slack kicker and ease an armful of sheet through the tack. Not a problem. Prob no worse than a 5-oh with rake and kicker on.

Got some vid from the weekend should illustrate it when I get round to cutting it.

Dan

 

BalticBandit

Super Anarchist
11,114
36
it's not about how much you pay...hence the shift in industry towards openSource.
And I'm not about to say we can model a planing hull accurately, thats why I'm after CAD...to model, validate, improve. We can do a decent job of the aero though...thats our expertise.
What "open source" shift? Oracle, MS and IBM are all doing very well in their relative aspects of this.

In fact much of "open source" really is kind of what you are doing here - trying to get others to give you their work for free so that you can make money on it. Not particularly ethical in my book.

 

bistros

Super Anarchist
1,264
13
May I ask which Goat?

Is there CAD knocking around for them?
What format in decreasing order of quality Iges, Dwg, Dxf
Would be interesting to see a comparison of the Woof, BMMII and L34.232 12' skiffs. With plenty known on actual performance of the Woof then there would be a good baseline for scaling the results into the real world.
Yep 3D models of each hull. no idea about foils, rigs etc. Talk to the Goat and he can get you started.
That would be Bill E. Goat here. He's posted to your thread.

--

(another different) Bill

 

mightyshoulders

New member
10
0
I'm not after cad for the work they have put into it... thats rediculous!

and i was talking about the opensource shift in the cfd community...which ms and ibm aren't involved in.

Thanks to all that have offered me CAD both on thread and off. greatly appreciated.

When I've got some pretty pictures for you all to rip apart I might pop it on here.

it's not about how much you pay...hence the shift in industry towards openSource.
And I'm not about to say we can model a planing hull accurately, thats why I'm after CAD...to model, validate, improve. We can do a decent job of the aero though...thats our expertise.
What "open source" shift? Oracle, MS and IBM are all doing very well in their relative aspects of this.

In fact much of "open source" really is kind of what you are doing here - trying to get others to give you their work for free so that you can make money on it. Not particularly ethical in my book.
 

bistros

Super Anarchist
1,264
13
it's not about how much you pay...hence the shift in industry towards openSource.
And I'm not about to say we can model a planing hull accurately, thats why I'm after CAD...to model, validate, improve. We can do a decent job of the aero though...thats our expertise.
What "open source" shift? Oracle, MS and IBM are all doing very well in their relative aspects of this.

In fact much of "open source" really is kind of what you are doing here - trying to get others to give you their work for free so that you can make money on it. Not particularly ethical in my book.
Ouch. I live in the Open Source world. Where do you think Microsoft got it's TCP stack? Most commercial products out there have cribbed published ideas from open source roots shamelessly - UC Berkeley provided the foundations for the TCP/IP protocol. The SMTP mail protocols developed originally by Eric Allman in Sendmail are used heavily in Exchange and every other mail server. The most popular and reliable web server out there by a mile is Apache - open source.

All academic publication is typically open source - by it's nature. You can't publish a dissertation or doctoral thesis for peer review without opening your Kimono.

The catch with GPL Licensing is that the person using the "open source" is obligated to publish their own derivative works source code - contributing back to the pool of knowledge from which they drank.

Open source is very ethical - but building closed-source products on open source roots is not.

It's perfectly ok for you and I to reserve our code and make money from it, just as it is perfectly fine to create an open source product as a commercial venture. Open source isn't about "free" as in money - it is about "free" as in freedom. Capitalism and open source can exist fine together.

--

Bill

 

mightyshoulders

New member
10
0
bob on

it's not about how much you pay...hence the shift in industry towards openSource.
And I'm not about to say we can model a planing hull accurately, thats why I'm after CAD...to model, validate, improve. We can do a decent job of the aero though...thats our expertise.
What "open source" shift? Oracle, MS and IBM are all doing very well in their relative aspects of this.

In fact much of "open source" really is kind of what you are doing here - trying to get others to give you their work for free so that you can make money on it. Not particularly ethical in my book.
Ouch. I live in the Open Source world. Where do you think Microsoft got it's TCP stack? Most commercial products out there have cribbed published ideas from open source roots shamelessly - UC Berkeley provided the foundations for the TCP/IP protocol. The SMTP mail protocols developed originally by Eric Allman in Sendmail are used heavily in Exchange and every other mail server. The most popular and reliable web server out there by a mile is Apache - open source.

All academic publication is typically open source - by it's nature. You can't publish a dissertation or doctoral thesis for peer review without opening your Kimono.

The catch with GPL Licensing is that the person using the "open source" is obligated to publish their own derivative works source code - contributing back to the pool of knowledge from which they drank.

Open source is very ethical - but building closed-source products on open source roots is not.

It's perfectly ok for you and I to reserve our code and make money from it, just as it is perfectly fine to create an open source product as a commercial venture. Open source isn't about "free" as in money - it is about "free" as in freedom. Capitalism and open source can exist fine together.

--

Bill
 

BalticBandit

Super Anarchist
11,114
36
it's not about how much you pay...hence the shift in industry towards openSource.
And I'm not about to say we can model a planing hull accurately, thats why I'm after CAD...to model, validate, improve. We can do a decent job of the aero though...thats our expertise.
What "open source" shift? Oracle, MS and IBM are all doing very well in their relative aspects of this.

In fact much of "open source" really is kind of what you are doing here - trying to get others to give you their work for free so that you can make money on it. Not particularly ethical in my book.
Ouch. I live in the Open Source world. Where do you think Microsoft got it's TCP stack? Most commercial products out there have cribbed published ideas from open source roots shamelessly - UC Berkeley provided the foundations for the TCP/IP protocol. The SMTP mail protocols developed originally by Eric Allman in Sendmail are used heavily in Exchange and every other mail server. The most popular and reliable web server out there by a mile is Apache - open source.

All academic publication is typically open source - by it's nature. You can't publish a dissertation or doctoral thesis for peer review without opening your Kimono.

The catch with GPL Licensing is that the person using the "open source" is obligated to publish their own derivative works source code - contributing back to the pool of knowledge from which they drank.

Open source is very ethical - but building closed-source products on open source roots is not.

It's perfectly ok for you and I to reserve our code and make money from it, just as it is perfectly fine to create an open source product as a commercial venture. Open source isn't about "free" as in money - it is about "free" as in freedom. Capitalism and open source can exist fine together.

--

Bill
TCP/IP came from DoD funded work on DARPAnet. QED it was not funded the way today's Open Source is. It was funded the same way NOAA charts are. IE you can digitize them or apply to get digitized copies of them from The Government for relatively low cost and then resell them the same way Garmin does.

Standards based protocols like SMTP, SMB etc. are often published even by commercial enterprises like MS and IBM (SMB specs) for interop purposes. But that's more like publishing the DWX standards or the MPP protocols used by multi-core CFD programs to do parallel processing (something both IBM and Microsoft offer capabilities for, as well as Linux and once upon a time SUN).

While it is true that academic publishing is somewhat Open Source, it IS protected by both Copyright and potentially Patent law. And there are numerous instances where academic work has been then rewarded through both processes - and rightly so. Creatives deserve to get paid.

So if you can't MODEL the CAD of a planing hull accurately, then you should buy it, just like if you can't paint a painting you should pay the artist who painted it instead of just scanning it, or if you can't implement a TCP/IP compatible stack you should pay someone to do it rather than waiting for them to get paid (by Redhat or IBM) and then taking the source for it for free.

So the ethics of asking for something for free without upfront disclosing that it is not only "for profit" but "for profit" for a corporate enterprise (ie more than just building your own) is to me no less dubious than our dear Doug Lord's use of "submarine patents" that don't properly disclose Prior Art.

Me - I work with both "open source" and "closed source" software. And my unfortunate experience has consistently been that Open Source business advocates are looking for the Free Lunch, and Open Source devs are using GPL republishing requirements as a way to stroke their personal egos more often than not.

 

ntman

Super Anarchist
1,444
2
afaik bill egoat is the only one here who has offered you some cad files of a skiff that he has actually designed and is wide spread in use. he has more experience in the this stuff than just about anyone here barring perhaps the occasional visit by Mr bethwaite et al.

 

teknologika

Anarchist
748
1
I can provide a model of dave lister's moth and some fastacraft foils if you want to CFD the world's fastest home-built moth
Can I have it? :)
Um no .. Jon should not be offering it either as it is not his design to give. I have the design as well, (and one of the boats), but the only person who has rights to the design is the designer John Gilmour.

He gets paid a fee for every boat of his design that is made.

 

ferrero

Member
92
0
I can provide a model of dave lister's moth and some fastacraft foils if you want to CFD the world's fastest home-built moth
Can I have it? :)
Um no .. Jon should not be offering it either as it is not his design to give. I have the design as well, (and one of the boats), but the only person who has rights to the design is the designer John Gilmour.

He gets paid a fee for every boat of his design that is made.
It was worth a try anyway!

 

BalticBandit

Super Anarchist
11,114
36
I can provide a model of dave lister's moth and some fastacraft foils if you want to CFD the world's fastest home-built moth
Can I have it? :)
Um no .. Jon should not be offering it either as it is not his design to give. I have the design as well, (and one of the boats), but the only person who has rights to the design is the designer John Gilmour.

He gets paid a fee for every boat of his design that is made.
It was worth a try anyway!
QED my point about the ethics being used here.

 

bistros

Super Anarchist
1,264
13
I can provide a model of dave lister's moth and some fastacraft foils if you want to CFD the world's fastest home-built moth
Can I have it? :)
Um no .. Jon should not be offering it either as it is not his design to give. I have the design as well, (and one of the boats), but the only person who has rights to the design is the designer John Gilmour.

He gets paid a fee for every boat of his design that is made.
It was worth a try anyway!
QED my point about the ethics being used here.
Sadly correct. Hence my comment on the generation bereft of digital decency in our off-line conversation.

Just for the record ferrero, it wasn't "worth a try". It painted you as one in dire need of a sense of shame.

Here's a scary thought for you ... the Internet is forever. Whatever you say here will follow you for the rest of your life. Someday when a prospective employer is researching you for that dream job, your posts and comments can and will come back to haunt you. Want that high paying, high security, high standard of ethics job? You aren't going down the right path so far. Think before typing - you can't erase the Internet. Connecting you, your name, your address, your identity to your forum handles, IP address(es), service provider(s), browsing history etc. is exactly what atwola, atdmd, doubleclick and the like do. They do it well. They sell the information to anyone who pays, and they own the information. They know exactly who I, you and everyone else posting here is. Think about it.

Consider it the downside of your digitally-enhanced, easy to copy world.

--

Bill

 
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Phil S

Super Anarchist
2,608
233
Sydney
And modelling a moth hull anyway is a bit of a waste of time as moths now goes really fast when the hull is not even in the water. Dave may go the fastest but the hull shape has very little to do with it.

 




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