New Approach to Hull Testing & Rapid Empirical Innovation Program Unveiled.
Hull testing literally has been taken out of the box and into the open ocean with M Ship Co.’s new Rapid Empirical Innovation (REI) program. The REI approach allows scaled-down hull models of recreational and racing sailboats, motor vessels, and cargo and military ships to be towed in real-life weather conditions by a self-powered FLOWT (short for “fast, low-cost, open-water testing”) platform rather than by a traditional towing mechanism used in a controlled indoor basin or “tank.” Among other advantages, the REI program saves designers, naval architects and boat builders 50-80 percent of the cost that it would take to utilize a conventional tow tank, without sacrificing accuracy or waiting for tank access.
“The REI program certainly is an unconventional approach to conventional tank testing,” said M Ship Co. Executive Director and Co-Founder Bill Burns, describing the FLOWT platform’s 20-foot pontooned hull, which--with its knife-edged hulls, multiple computer work stations and various adaptable structures—looks something like an inspired Lego® design while underway, “but the implications of it are of far-reaching importance to the people who shape our industry.”
Burns explained that two different hull models can be evaluated in tandem, providing immediate and direct hull-to-hull comparisons. After the hulls are fabricated they are outfitted with identical high frequency 6-DOF accelerometers that provide comprehensive motion and acceleration comparisons. The models are then tested on the FLOWT platform, which provides real-time force, trim and acceleration measurements and allows the hulls to be analyzed on power, speed, payload, fuel efficiency, range capability and ride quality.
“We can offer test programs that can use a constant baseline with a new design or test two new designs at the same time,” said Burns. “Fully instrumented, rough water testing at the same time is unique and offers immediate and unequivocal comparison of ride quality performance between designs.”
M Ship’s REI program has tested a range of vessels, including catamarans, displacement monohulls, advanced planing hulls and submersibles. In addition to optimizing design for ride quality, speed and fuel efficiency, its applications include validating CFD and untested claims; comparing different designs with instant results; developing a unique design for market differentiation; and proving concepts for patentability and investment. Accuracy of the REI program’s data has been validated at the U.S. Navy’s David Taylor Model Basin, one of the largest ship model basins in the world, where it was re-analyzed in both smooth and rough water.
“The REI results exceeded our 95 percent threshold,” said Burns. “The REI calm water resistance measurement has been shown to have an absolute accuracy of four percent at five knots model scale and improves to three percent at 15 knots model scale. The results are well within the scatter range you would expect between different tow tanks.”