Kiteboard Team: Eddie Obrupta, Sam Parker, Adam Paxson, Tom Peleg, Pawel Zimoch
Advisors: Peko Hosoi and Alex Slocum
[Outgrowth of Maui STE@M Workshop]
The goal of our current investigation is to develop a physical model of kite surfing to inform the development of new kite surfing equipment designs. We are particularly interested in improving the steady-state performance of kite surfing equipment at low wind speeds, where we believe there is an opportunity to grow the market.
Our model consists of coupled aerodynamic and hydrodynamic models that describe the forces acting on the kite and the sail, respectively. The performance of the equipment is quantified by comparing it to an ideal aerohydrofoil (an above-water airfoil rigidly connected to an underwater hydrofoil), which does not need to support its own weight. The steady-state performance of a kite surfing system is most directly affected by the amount of drag required to maintain the kite in the air and to keep the surfer above the surface of the water. Our analysis indicates that the key limiting factor in the performance of current kite surfing equipment is the drag acting on the board.
The total drag on the board is composed of two components: the force required to support the surfer’s weight on the water, and the force required to deflect the kite’s pulling force, so that the board can travel at an angle, giving the surfer the ability to surf upwind. Particularly in low wind conditions, the drag is dominated by the force required to keep the surfer on the water. Unlike traditional sailing, in kite surfing, the entire weight of the surfer is supported by the dynamic pressure acting on the surfing board. Hence the hydrodynamic efficiency of the board in supporting the surfer’s weight plays a significant role in determining steady-state sailing performance.