Fin Design on Circus...

[Shnick]

I ran across this photo on the net and noticed the fin on one side is longer than the other. i understand the aerodynamics behind it all, but why is one taller that the other?? (see photo)

Hmmm...

Shnick

 

[Lake S.P.O.R.T.]

They discovered that when the boat was traveling at 200 mph at the end of the straightaway and then turned left, the change in airflow over the wing was causing a sudden change in the boats handling. With the fin sticking up above the right side of the horizontal wing the airflow was harnessed in such a way that it corrected this. If you look back at the evolution of the unlimiteds, particularly through the 1970's, you will see all sorts of wing shapes both vertical and horizontal.

 

[apache5056]

Think I might be of some benefit on the scale boats?... being they run at scale speeds

 

[Lake S.P.O.R.T.]

Perhaps. Keep in mind that things change when designs are scaled up from models or scaled down from lifesize. This would be very easy to add. If it did not work just remove it.

 

[Don Ferrette]

What you also need to look at is how low the horizontal wing in that pic is compared to what they run now. If you look at later model boats you'll see the wings are higher up to get them in "clean" air. The extension served as a band aid to the "hole" left in the air by the scoop as they entered the turn.

 

[Shnick]

So to be completely realistic, i should add the taller section to the left side, since this boat runs opposite of the full size counterparts...

Don, whatcha got for a spray gun??

Shnick

 

[Don Ferrette]

They only ran that extended vertical for a short time. There are plenty of CC pics out there without it. I shoot with a HVLP detail gun @ 10-15psi. The is actually a detail gun from a company called Speedway for about $30 that works very well. I bought one to shoot primer & was surprised at how it shoots as well as my other gun, which is starting to act up. I'm thinking of ordering a couple more Speedways truthfully.

 

[Propjockey]

Think I might be of some benefit on the scale boats?... being they run at scale speeds

Something to remember is...air and water molecules remain constant.