Kayak and Canoe Design Bulletin Board

Re: How does prismatic coefficient affect design?

Posted By: Nick Schade
Date: Sunday, 31 October 1999, at 9:47 a.m.

In Response To: Re: How does prismatic coefficient affect design? (Ian Johnston)

Cp is a ratio of the cross sectional area of the widest part of the boat times the length divided by the volume of the boat. It is not an characteristic you can point at saying, "There is the Cp".

You can not change the Cp without changing the design. Cp is a non-dimensional parameter. This means that if you change any dimension - length, width and/or depth - while holding everything else constant, you will not change the Cp at all. This is because when you change the length, the volume will increase proportionally so the changes cancel each other out, and the same for any of the other dimensions.

> So, in effect you are saying that it is the design that affects Cp not the
> other way around? By altering the design I would be able to get the Cp
> that I wanted but I could not get the design I wanted by altering the Cp?

> Two boats of different design "could" have the same Cp. Two
> boats of the same design would "have to" have the same Cp?

> I have probably said the same thing 3 or 4 times!!!

> Ian

Messages In This Thread

How does prismatic coefficient affect design?
Jeremy McConnell -- Saturday, 30 October 1999, at 2:55 p.m.

Re: How does prismatic coefficient affect design?
Nick Schade -- Saturday, 30 October 1999, at 4:47 p.m.

Re: How does prismatic coefficient affect design?
Ian Johnston -- Saturday, 30 October 1999, at 5:56 p.m.

Re: How does prismatic coefficient affect design?
Nick Schade -- Sunday, 31 October 1999, at 9:47 a.m.

Re: How does prismatic coefficient affect design?
lee -- Wednesday, 3 November 1999, at 8:58 a.m.

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