Memphis International Riverfront Regatta






			The Tunnel Hull is a strange 'bird'. While the Tunnel derives much of its high performance from air lift, it depends at the same time on its planing interaction with the water to maintain a stable and controlled 'flight'. This interdependence of water and air force dynamics is the key to the approach to Tunnel design. Tunnel boats demonstrate such exceptional performance because they have a "wing" or aerofoil built-in to their design. The tunnel "roof" and the upper deck surface form the lower and upper surfaces of the aerofoil, respectively. When properly designed, it is this aerofoil, and the aerodynamic lift it generates, that gives the tunnel boat its great performance.		What makes the tunnel hull work? This is a multi-part article on the engineering basics of what makes the tunnel hull work. This week, we will look at the principles of operation and Lift/Weight balance. To understand the balance of hydrodynamic and aerodynamic influences on tunnel boat performance and stability, we must examine the fluid dynamic forces involved. Several requirements must be satisfied for an object to maintain a steady straight-line velocity. For more information visit the following website: http://boatdesign.net/articles/tunnel-hull-design/index.htm