Sorry to be late to this discussion, but I think the explanation for the starting vortex is simple and the same as for the trailing vortices:...
Xfoil can be used to model the section characteristics of an articulated rudder that has no slots between the elements. You will still need to...
The lower hull speed of the smaller boat is the same thing as the lower speed from operating at the same Froude number. Say you built a quarter...
I misspoke in my description of Froude scaling. What I should have said is with Froude scaling, velocity is scaled with the square root of...
Talking scaling alone, Froude scaling is appropriate for hydrofoils. If weight scales as length^3, foil area scales as length^2, and you want to...
Instead of thinking of aspect ratio, you should instead consider span and area separately. Unfortunately, you are constrained in span by the...
VLM would be the simplest. A panel code would be the next step up.
The Vortex application is this lifting line spreadsheet. You can read about its derivation here. Although lifting line analysis does assume high...
Actually, there is a very good reason for considering aerodynamic lift in the context of yacht performance. Here is what the lift and drag...
I don't believe it would work on a displacement hull. Research with hydrofoils has shown that flow separation is necessary for ventilation, and...
A flexible trailing edge, or flap mounted with a flexure, can act passively to transition smoothly and automatically between high and low speed...
An exponential function has the property that the rate of change is proportional to the value of the function. They arise naturally as the...
Polymer injection into the boundary layer can substantially reduce the skin friction drag. In 2010, BMW Oracle Racing experimented with polymer...
There are fast dynamics and slow dynamics to a boat's motion. Most performance related dynamics are comparatively slow and can be considered to...
The wake trails at the apparent wind angle. This is due to the wake being convected with the true wind while simultaneously being generated at...
Here is how the water rudders are rigged on a Dehavilland Beaver's floats. The bellcrank on the air rudder (upper right) acts as your wheels....
You might want to take a look at what Ernest O. Tuck and Leo Lazauskas say about it in Optimum hull spacing of a family of multihulls. Search...
XFLR5 could be a place to start. Or you might start with a vortex lattice code like AVL. I've not used XFLR5, but I think it is a lifting line...
I like the looks of that much better. To optimize the length of the flat portion you'd have to actually do some analysis with something like a...
The main benefit of an asymmetrical section is drag reduction. The lift on the board has to equal the side force applied by the sail rig, so the...