This facility features a large-scale, low turbulence, high-subsonic Mach number wind tunnel for fundamental aerodynamic research. The tunnel has a maximum free-stream Mach number of 0.6, and a 3x3 ft by 9 ft long test section. The tunnel uses a 8 ft diameter, two-stage fan with variable pitch blades. It is powered by a 1750 h.p. variable r.p.m. AC motor. Turbulence management in the tunnel provides a very low turbulence intensity level of 0.05%, which is comparable to free-flight conditions.
The wind tunnel is a closed-loop design that utilizes a unique active air temperature control to maintain a constant, spatially uniform, free-stream temperature. This feature is essential for measurements using heat-transfer-based sensors such as hot-wires, and for optical measurements that are designed to detect time-dependent density variations.
The test section has windows that cover 60% of the area on all four sides. This provides flexible optical access for laser-based measurements such as LDV, PIV and flow visualization. The windows are all removable and interchangeable with specialized panels that are used for mounting models or providing access for sensor traversing mechanisms.
The wind tunnel was fully designed at Notre Dame. This included innovative turning vanes that also functioned as heat exchanger elements that maintain a constant tunnel air temperature with minimal pressure loss and temperature gradients. The cooling turning vanes are supplied with 45° F water from an ice-storage chilled water system. The chilled water system provides continuous cooling up to a free-stream Mach number of 0.5. Between Mach 0.5 and 0.6, stored ice is depleted.