Hi everybody,
I’m writing a story about fin design for a campus science magazine at UC Santa Cruz. What I want to do is to understand the hydrodynamics that make fins work. Then the next step will be to understand what the modifications to a basic fin accomplish. I’ve spoken with a variety of fin designers, salesmen, and surfers and received a range of answers with varying scientific plausibility. So I thought I’d ask you guys, who have created an actual (or virtual anyway) forum on the topic.
Please answer as many or as few of these questions as you like. Use as many words as you like, but don’t feel compelled to write theses… By the way, for simplicity, let’s limit the discussion to shortboards with thruster setup.
OK, here goes:
Years surfing?
Physics/Engineering background?
Have you ever swapped out the fins on a board and actually felt a difference?
Do you think a performance gap exists in surfing that a new fin design could fill?
How does lift help a surfboard?
In what direction does the lift vector point?
What is drive and where does it come from?
What is projection and how does it differ from drive?
What is the significance of foil?
Does a double-sided foil generate any lift?
On a single-foil fin, what is gained by making the trailing edge slightly concave?
When you drop in on a wave and start your bottom turn, you speed up. Where does that speed come from? How does fin design, esp. shape, affect the change in speed?
Many thanks in advance for taking the time to contribute. Come to Santa Cruz with some graph paper and I’ll buy you a beer.
Hugh
p.s. If you want to be all scientific and double-blind about this, don’t read anyone’s answers until you’ve posted.