The historic Glenn L. Martin Wind Tunnel (GLMT) is an independent University of Maryland research facility and a key testing resource for the Alfred Gessow Rotorcraft Center.
Built by Glenn Martin and first commissioned in 1949, it remains a premier subsonic test facility for rotorcraft.
It is a closed-circuit tunnel with a closed test section of 7.75 ft. height and 11 ft. width and a maximum speed of 205 knots, which translates to Mach 0.3 for sea level conditions.
The sphere test turbulence factor is 1.05 and measured hot wire intensity is 0.21%. It has a rotating turn-table, in-house balance system, PIV-camera access, and precise speed control.
The Maryland Compound-Rotor Rig and the Maryland Tiltrotor Rig are tested in this tunnel.
A Vertical Flight Heritage Site
In 2025, the University of Maryland's Glenn L. Martin Wind Tunnel was designated a Vertical Flight Heritage Site by the Vertical Flight Society.
Citation: “Beginning in 1949, the Glenn L. Martin Wind Tunnel has investigated advanced aircraft designs, including single main rotor, tandem, coaxial, compound, tilt-rotor, tilt-wing and lift-jet vertical flight aircraft, and continues to advance the understanding and technologies of bearingless rotors, smart rotors, slowed rotors, ducted rotors and electric-powered rotors. The tunnel, along with the Alfred Gessow Rotorcraft Center, has provided education to generations of aeronautical students and has to date impacted at least 100 graduate theses in the rotary-wing field alone.”
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