Anechoic
Chamber and Wind Tunnel
The anechoic chamber at the Hessert Center has a working space 20 feet (6.1 meters) wide by 26 feet (7.9 meters) long by 8 feet (2.4 meters) high with 22 inch (55.9 cm) fiberglass sound absorbing wedges on all six sides. This wedge configuration provides a low frequency cutoff of about 100 Hz. Above the cutoff frequency; the wedges have a coefficient of energy absorption at normal incidence of 0.99 or greater. A low turbulence subsonic free-jet/closed test section wind tunnel (see sketch below) has been developed to fit into this anechoic chamber for aerodynamic measurements and sound pressure level and sound intensity measurements generated from propellers, fans, pumps, airfoil configurations, etc. The cross-sectional area of the test region is four square feet (0.37 square meters) with a maximum velocity of about 100 feet/second (30.5 meters/second). This wind tunnel has been designed so that it can be removed to accommodate other acoustic experiments. Current research has applications for aircraft as well as automotive and marine vehicles.
