The dynamic pressure is essentially a measure of the fluid’s potential energy whilst the flow velocity is proportional to fluid’s kinetic energy....
Thanks Tom.
Good stuff Mike, thanks a lot for sharing. Lasers do use up to about 6 degrees of heel (gives about 10% more RM in exchange for losses from rig...
Tom, does a spanwise linear wake wash velocity distribution also imply a linear variation of downwash angle along the span and a linear variation...
If only the shear drag can be localised, then is Mikko’s plot showing that shear drag is highest in the middle and lowest at the ends? Why would...
Surely you can’t ignore the yaw balance in a moth will all that windward heel?
Technically there are three force balances and three moment balances, but a full 6DoF is a bit tough without a lot more data than is easily...
If the drag is predominantly induced drag and that is a result of “leakage” around the head and foot, wouldn’t you expect drag to be lowest in the...
Hi Dolfiman, thanks for sharing. How do you account for the induced drag of the keel etc if you assume no leeway? I’ve now added Flat and ease...
Well, I guess it’s something to investigate in the VPP... gives me a reason to play!
Isn’t that indicative that the daggerboard is too big and the chord could be cut? It might hurt during manoeuvres but a price worth paying?
You’re right Doug. Last night I added HMmax as a constraint and Cl is varied to stay within the limit, but the L/D ratio is assumed constant....
Aero data at the moment is simply a Cl of 1.35 and a Cd of 0.3 (L/D of 4.5), which I have taken from a hybrid of data from Marchaj, Fosatti, Day,...
I decided to recode it from scratch after failing to find the problem... and it now works!
Thanks Doug. The true wind to heading is just an input, all the calcs then take leeway into account so that apparent wind angle is against course....
Hi, I am trying to put together a VPP for a simple unarig dinghy (Laser) and am getting some curious, and presumably wrong, results. Given a true...
For a centreboard, as opposed to a daggerboard or fixed keel, is longer always better given that it means a longer slot in the bottom of the hull...
The OP was really related to finding a sail area. I’m surprised no one has mentioned that this is more dictated by stability factors than a target...
But you theory doesn't explain how bouncing bombs bounce...
Consider the case of the bouncing bomb. That ain't buoyant (and early prototypes didn't have back spin, but still bounced).
