The John J. Harper Wind Tunnel

The wind tunnel, located in the basement of the Guggenheim Building, is designed for aerodynamic testing and research. Its test section measures 7 feet by 9 feet, providing a spacious area for various experimental setups. The test section is described as "optically highly accessible," which means it is equipped with features such as transparent walls or strategic viewing ports that allow researchers to observe and record experiments from multiple angles using advanced imaging techniques.

The wind tunnel is equipped with an external balance system and a turntable. The external balance allows precise measurement of aerodynamic forces, such as lift and drag, as well as moments—rotational forces that cause the test models to pitch, yaw, or roll about their axes—acting on test models without interference from the tunnel structure. The turntable enables rotation of the test object, facilitating studies of airflow from different orientations and making it possible to simulate a wide range of flight conditions.

The facility is capable of generating wind speeds up to 120 miles per hour, making it suitable for high-speed aerodynamic experiments. This capability supports research on various types of aircraft, including fixed-wing airplanes, rotary-wing helicopters, and propulsion systems, as well as investigations into other aerodynamic phenomena.

To enhance the quality of research, the wind tunnel is equipped with advanced diagnostic tools. These include:

• Concurrent time-resolved Particle Image Velocimetry (PIV) flow field measurements. 

This technique uses laser illumination and high-speed cameras to visualize and measure the velocity of particles seeded in the airflow, providing detailed, time-resolved data on how air moves around test objects.

• Unsteady pressure measurements:

Sensors capture fluctuating pressure data on the surface of test models, which is critical for understanding aerodynamic loads during dynamic conditions.

• Six-degree-of-freedom load measurements:

The facility can record forces and moments along all three axes (x, y, z) and rotations about those axes (roll, pitch, yaw), enabling comprehensive analysis of how aerodynamic forces act on test objects in all directions.

The John J. Harper Wind Tunnel is a formidable research instrument, offering versatile testing capabilities and advanced measurement technologies to support cutting-edge studies in aerodynamics and flight science.

Accessing Harper

The wind tunnels are intended to be open-use shared spaces that are used as prolifically and efficiently as possible by as many users as possible. To accommodate this philosophy, all users must complete the requirements laid out by the GT-AE Shared Spaces committee in order to gain access.

The Harper tunnel employs a two-tier system for gaining access: (1) entry only, and (2) full operation.