As one of very few academic tow tanks in the United States, the towing tank at Virginia Tech gives engineering undergraduate and graduate students valuable experience in state-of-the-art facilities, training on cutting-edge technologies, and ultimately the opportunity to work to advance military research, which plays a critical role in workforce development. The facility is conveniently located in close proximity to U.S. Navy and commercial facilities in the mid-Atlantic region, notably in the Washington, D.C. and Norfolk areas.
The facility underwent instrumentation upgrades and modernization in 2022. Working with DLBA (a division of Gibbs & Cox), in partnership with Edinburgh Designs, the former towing carriage was completely removed and replaced with a high-speed simple frame design that no longer allows researchers and students to ride on the carriage. The carriage is now remotely operated and equipped with cameras for monitoring, and a vertical planar motion mechanism (VPMM) has been installed to run nontraditional experiments, such as a surface vessel with controlled motions in the vertical plane causing it to slam into the water surface.
The carriage itself is capable of a constant maximum velocity of seven meters per second (or 23 feet per second). The carriage is propelled with a belt driven system with one large electric motor on each rail. The brakes are electromagnetic, providing enough braking force for the high acceleration and deceleration loads. The main structure of the carriage is constructed using ITEM aluminum extrusions, in combination with large custom aluminum parts. These extrusions allow for the easy construction and modification of experimental set ups.
A dedicated data acquisition system and a suite of new sensors for experiments, such as force gauges, accelerometers, potentiometers, wave probes, inclinometers, and pressure sensors, were also added to the tow tank.
The vertical planar motion mechanism allows for controlled motion experiments for a model by prescribing heave and pitch motions. The mechanism is manipulated with two linear actuators, and the mechanism will have controllable heave motions with a range of 64 centimeters. The vertical planar motion mechanism was designed by DLBA and is being constructed by Virginia Tech.
While Virginia Tech’s Towing Tank is relatively small in size, the maximum carriage speed is over twice as fast as similarly sized tow tanks. The basin measures 98 feet long, six feet wide and four feet deep. The new upgrades to the facility enable precision measurements, making the facility well-suited for small-scale ocean vehicles and platforms, including small craft, AUVs, and biomimetic robots.
Experimental capabilities include resistance and propulsion testing, linear and nonlinear maneuvering experiments, and seakeeping model development. In particular, the improved facility can help to validate new analytical models for submerged vessels maneuvering in waves or computational fluid dynamics models for studying the slamming of small craft in waves.