High Speed Towing Tank
The high-speed towing tank is 313 feet long and 16 feet wide, and can support water depths as high as 8 feet. It is one of the highest speed towing tanks in the world with a monorail supported, cable-driven carriage capable of speeds of up to 100 feet per second with speed control of .01 feet per second.
This tank can produce a wide variety of wave types through an articulated double-flap programmable wave maker. This wave maker generates both regular waves and pseudorandom waves and can be programmed to produce nontraditional wave forms such as wave pulses, complex periodic waves and dual and triple wave trains. The wave maker can be used to generate both regular and irregular waves with heights up to 18 inches.
Shallow water and shoaling conditions can be duplicated with the installation of "false" bottoms. Plunging surf can be produced on a 40 foot surf beach. Computer programs adjacent to the tank facilities provide menu-driven selection of the following types of wave spectra:
- ITTC, ISSC, Pierson-Moskowitz, Bretschneider
- Noznesenski-Netsvetayez (Russian)
Rotating Arm and Oblique Sea Basin
The oblique sea basin, one of only two of its kind in the United States, has a length of 75 feet, a breadth of 75 feet and can support water depths of up to 6 feet. The facility, which has been designated a historic mechanical engineering landmark, comes equipped with a moveable overhead rail that permits vehicles to be towed in oblique waves at speeds of up to 10 feet per second. The wave-maker in the basin has the ability to generate both regular and irregular waves with heights of up to seven inches.
The basin's most unusual but distinguishable feature is its rotating arm. This arm, with a 32-foot radius, can accommodate test on vehicles moving at speeds from 0 to 50 feet per second. The arm enables researchers to obtain highly accurate information about the maneuverability of ships in both calm and rough seas.
Numerical/Computational Fluid Dynamics
In addition to the experimental facilities, research addressing engineering problems involving complex flow phenomena is conducted using computational fluid dynamics. The laboratory’s simulation software suite is made up of a combination of commercial and in-house modeling codes, several mesh generation tools, and advanced flow visualization tools. Past and on-going projects encompassing numerical simulation-based research include analysis related to supercavitation, vortex-induced vibrations, extreme wave loads on off-shore structures, hydrodynamic and hydroacoustic signatures of submerged bodies and wake hydrodynamics, and aero-hydromechanics of high performance racing yachts. The later activities involved design analysis support for the America’s Cup and Volvo Ocean Race teams and boat designers.
Instrumentation and Design
The instrumentation and design group is involved in developing mechanical, electronic, and microprocessor based systems. In addition to designing and manufacturing specialized equipment needed to support research initiatives at both the Davidson Laboratory and Stevens Institute of Technology, contracts have been negotiated with other organizations including:
- Department of Defense (DOD)
- Department of Transportation (DOT)
- New Jersey Department of Transportation (NJDOT)
- E. J. Brooks
- Block Drug Company
The Davidson Laboratory electronics shop provides complete instrumentation support for the full spectrum of the lab's experimental studies as well as maintenance and repair facilities for all of the electronic equipment used for laboratory and field studies.
Complete instrumentation setups can be designed and constructed in-house with minimal lead time requirements. Our custom-designed systems can be as simple as a few lights attached to a model or as complex as a multi-axis servo controller utilizing PC based digital signal processing. Special capabilities include:
- Installation of bonded resistance strain gages for force measurement.
- Motor Control Systems from tine stepper motors to large industrial machinery.
- SMT prototyping and repair capabilities.
- Remote control systems using RF or infrared techniques.
The electronics shop also provides equipment and support for video and still photography systems including high-speed underwater photographic systems designed for our towing tank studies.
Personnel hold FCC radio operator's licenses and New Jersey master electrical contractor's licenses.
Machine and Model-Making Shop
The Machine and Model-Making Shop is a fully equipped machine shop staffed by two machinists working with virtually all types of materials. State-of-the-art equipment, CNC milling machine, CAD and other computer software, and decades of experience are drawn upon to build reduced-scale models of vessels and marine structures, as well as specialized laboratory and field instrumentation. The facilities are made available to staff and students after an appropriate initial training period.