Surface Wave Topography, Resistance and Seakeeping of a Wedge-Shaped Hull

Modern displacement monohulls exhibit high wave-making resistance near and above their designated hull speed, which occurs when the ratio of waterline length and wavelength equal one (Froude number ~0.40). A unique, yet simple, wedge-shaped hull form has interesting features, such as a sharp bow angle, rectilinear sides, and a linear aftward taper, that could greatly improve hydrodynamic efficiency at a range of high speeds. Such improvements would result in higher fuel efficiency, lower operating cost, improved ride comfort, and reduced stress on the hull. Testing is being performed on two similar wedge-shaped hull models at overall lengths of 79 inches and 24 inches to understand the hydrodynamics characterized by form drag, wave drag, seakeeping, and wake topography. The hull’s seakeeping ability, in regular and irregular waves, is found by attaching the larger model to a carriage and measuring pitch and heave with potentiometers. Similarly, the resistance is measured through the use of strain gauges mounted on the same carriage. To map the topography of the surface waves, two tools are used, Light Detection and Ranging (LiDAR) and static wave probes. The smaller model is used to find the velocity profile of flow around the model through a method called Particle Image Velocimetry (PIV). These PIV measurements give a better understanding of interesting fluid flow such as vortex shedding. It is hypothesized that the wedge-shaped hull, compared to conventional modern displacement monohulls, will show a reduction in wave-making resistance at speeds above hull speed and an improvement in seakeeping factors.