Located in Penn State's
Applied Research Laboratory, the Garfield Thomas Water Tunnel (GTWT) is the U.S. Navy's principal experimental hydrodynamic research facility.
The GTWT is a 48-inch diameter, closed-circuit, closed-jet water tunnel used for a variety of tests: steady and unsteady forces and moments, optical flow field surveys, pressure distributions, cavitation performance, noise and vibration measurements, flow visualization, torque, and thrust. For many years, the GTWT was the largest circulating water tunnel in the world and has been declared a historic mechanical enginering landmark by the American Society of Mechanical Engineers.