Evaluation of Transonic Hull for Shock-Free High Speed Operation
Shock is inherent in conventional monohull craft at speed in adverse seas. It can be alleviated but has not been eliminated. Principal causes are firstly to attain speed a craft’s forebody is above water level exposing its undersurface to high wave impact pressures. Secondly, large exposed area needed ‘for buoyancy reserve forward’ assures large impact forces. Thirdly, all published definitions of slam are descriptive, which has impeded a solution to the shock problem.
New causal definition of shock: Calderon applies conservation of energy that explains shock and slam phenomena. A shock is a violent transfer of wave energy to a vessel causing violent accelerations in pitch, heave, and surge.
Calderon’s energy-based solution to shock problem: If a vessel traverses a wave without disturbing its contour, momentum and orbital motion, there is no energy available to cause shock or slam.
Transonic’s shock-free solution: The 3-D shape designed by Calderon within a slender triangular planform has been tested by Oceanic Consulting Corporation in the 200 metre tow tank of the Canadian Government with several irregular waves, confirmed in tests of the XTH-20 boat.
This experimental data substantiates the following characteristics of Transonic Hull (TH):
Avoids piercing - because Transonic hull does not generate a bow wave it is able to slice and separate ocean waves into right and left wave sides that flow along hull’s flat sides, retaining wave curvature, momentum and orbital energies substantially intact.
Maintains near zero pitch in waves at all speeds to preclude exposing undersurface to impact forces.
The conditions above occur above a threshold speed in which Transonic’s momentum counters buoyancy and dynamic forces from wave.
Consequently, as momentum increases with speed, acceleration in waves decreases rather than increases.
Alberto Calderon - Executive Director and Chairman, Transonic Hull Company
Alberto A. Calderon received BS in Mechanical Engineering and MS in Aeronautical Engineer from Stanford University. Following research work as Research Associate at Stanford, he worked as a consultant in aerospace field in variable geometry wings, including OV-10A, AG, F111B, QSRA aircraft in the US and Airbus and Concorde II in France.
His naval work begun as Chief of Hydrodynamics of the St. Frances Challenge for America’s Cup. Their boat placed second at the America’s Cup in Perth Australia, with Calderon’s front and rear rudders. This earned Calderon position as Principal Designer to Team Dennis Conner in two America’s Cup campaigns in San Diego. Calderon’s research on ways to reduce wave making of Conner’s America’s Cup hull led to his formulation of Transonic Hull theory with a full form that was outside America’s Cup Rule. Calderon patented the hull form and founded Transonic Hull Company. He has directed its theoretical and experimental program reported in several recent papers published at HSMV, FAST, and SNAME conferences.