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Re: Strip: Rudder mechanism and blade
By:Palle Dam
Date: 11/25/2014, 7:55 pm
In Response To: Re: Strip: Rudder mechanism and blade (Bill Hamm)

Thanks Bill, I will use a NACA 0012 profile.
Now I just need to figure out the actual dimensions of the rudder. So far I have found 2 ways to calculate the rudder area:

First method:
(Length of waterline * Draft) / 30 = Rudder area
(528cm*11cm)/30 = 193,6 cm2 or (207.87"*4.33")/30 = 30 sq in

Second method:
About 1-2 % of the underwater lateral area (I assume "underwater lateral area" is the same as the wetted surface)
22600 cm2*0.01=226 cm2 22600 cm2*0.02=452 cm2
or
3503 sq in*0.01 = 35.03 sq in 3503 sq in*0.02 = 70,06 sq in

The 2 methods give different results. Which one should I use? Or are there other formulas?

When I have determined the optimal rudder area I will have figure out what the aspect ratio should be. I have read that high aspect rudders (long and narrow) have a low drag but are more prone to stall. The opposite is the case for low aspect rudders (Short and wide): Higher drag, but also higher stall angles. What will the best compromise be for a kayak?

Palle

Messages In This Thread

Strip: Rudder mechanism and blade
Palle Dam -- 11/21/2014, 1:50 pm
Re: Strip: Rudder mechanism and blade
Nick Schade - Guillemot Kayaks -- 11/21/2014, 3:35 pm
Re: Strip: Rudder mechanism and blade
Palle Dam -- 11/22/2014, 8:23 am
Re: Strip: Rudder mechanism and blade
John Kroeze -- 11/21/2014, 3:43 pm
Re: Strip: Rudder mechanism and blade
Craig -- 11/22/2014, 1:18 am
Re: Strip: Rudder mechanism and blade
Allan -- 11/22/2014, 1:33 am
Re: Strip: Rudder mechanism and blade
Palle Dam -- 11/22/2014, 9:14 am
Re: Strip: Rudder mechanism and blade
JohnAbercrombie -- 11/22/2014, 1:40 pm
Re: Strip: Rudder mechanism and blade
Bill Hamm -- 11/23/2014, 1:44 am
Re: Strip: Rudder mechanism and blade
Palle Dam -- 11/25/2014, 7:55 pm
Re: Strip: Rudder mechanism and blade
JohnAbercrombie -- 11/25/2014, 8:22 pm
Re: Strip: Rudder mechanism and blade
Palle Dam -- 11/27/2014, 6:56 pm
Re: Strip: Rudder mechanism and blade *PIC*
JohnAbercrombie -- 11/27/2014, 7:56 pm
Re: Strip: Rudder mechanism and blade
Bill Hamm -- 11/30/2014, 12:56 am
Re: Strip: Rudder mechanism and blade
Palle Dam -- 11/30/2014, 9:11 pm
Re: Strip: Rudder mechanism and blade
JohnAbercrombie -- 11/30/2014, 11:36 pm
Re: Strip: Rudder mechanism and blade
Palle Dam -- 12/1/2014, 1:17 pm
Re: Strip: Rudder mechanism and blade
JohnAbercrombie -- 12/1/2014, 2:18 pm
Re: Strip: Rudder mechanism and blade
Bill Hamm -- 12/1/2014, 1:13 am
Re: Strip: Rudder mechanism and blade
Palle Dam -- 12/1/2014, 1:50 pm
Re: Strip: Rudder mechanism and blade *PIC*
JohnAbercrombie -- 12/1/2014, 2:27 pm
Re: Strip: Rudder mechanism and blade
Bill Hamm -- 12/2/2014, 12:41 am
Re: Strip: Rudder mechanism and blade
JohnAbercrombie -- 11/25/2014, 8:28 pm
Re: Strip: Rudder mechanism and blade
Bill Hamm -- 11/26/2014, 5:29 am
Re: Strip: Rudder mechanism and blade
scottbaxter -- 11/21/2014, 4:40 pm
Re: Strip: Rudder mechanism and blade *PIC*
Reg Lake -- 11/24/2014, 12:57 am