Aeroacoustics Research Facilities
 

Aeroacoustics Research Facilities

Semi-anechoic Chamber

The Semi-anechoic Chamber is one of a handful of facilities in the world that offers state-of-the-art sound reproduction capabilities to reproduce 3D spatial sound fields of anything from concert halls and office noise to airplane noise. The main feature of the 3D reproduction capabilities is the ability to reproduce "third-order ambionics."

Open Jet Flow-through Anechoic Chamber

The Open Jet Flow-through Anechoic Chamber is a 5.0 meter x 6.0 meter x 2.8 meter room covered with fiberglass wedges, with an approximate cut-off frequency of 250 Hz. High-pressure air is delivered from a tank farm pressurized to 200 psig.

The air flow is regulated via pressure regulators and control valves located in a piping cabinet, before being fed to a plenum and delivered to the jet nozzle issuing into the anechoic chamber. A pitot probe is embedded in the middle section of the plenum to provide, via a pressure transducer, the total pressure upstream of the nozzle. An exhaust fan, installed in the downstream section of a collector, captures the jet exhaust and minimizes air recirculation and possible local helium accumulation in the anechoic chamber.

Jet aeroacoustics measurements are typically performed using twenty microphones, supported from a boom that extends from the plenum stand. The microphone array has controlled rotation around a point located at the center of the nozzle exit plane. The microphones are positioned at a grazing incidence horizontal to the jet centerline plane and equally spaced by 5 degrees. The physical distance from each microphone to the nozzle exit is approximately 1.8 m. This distance is sufficient to ensure that the microphones are in the far-field when testing nozzles up to 2 cm in diameter. The microphones used are 1/8 in (3.2 mm) pressure field microphones, type 40DP from GRAS.

An open jet wind tunnel is incorporated in the facility for experiments conducted with a forward flight stream. A mixed flow design developed for minimal noise, provides the inlet flow. This flow is delivered to an axial flow muffler and acoustically treated duct work leading to the anechoic chamber inlet. An acoustically treated collector and duct work leads to an exhaust fan on the exit side of the system. This design results in an open jet, inside the chamber that is close to ambient pressure.

Reverberation Room

More information about this facility will be available soon.

 
 

About

The Penn State Department of Aerospace Engineering, established in 1961 and the only aerospace engineering department in Pennsylvania, is consistently recognized as one of the top aerospace engineering departments in the nation, and is also an international leader in aerospace education, research, and engagement. Our undergraduate program is ranked 16th and our graduate programs are ranked 15th nationally by U.S. News & World Report, while one in 25 holders of a B.S. degree in aerospace engineering in the U.S. earned it from Penn State. Our students are consistently among the most highly recruited by industry, government, and graduate schools nationwide.

The department is built upon the fundamentals of academic integrity, innovation in research, and commitment to the advancement of industry. Through an innovative curriculum and world-class instruction that reflects current industry practice and embraces future trends, Penn State Aerospace Engineering graduates emerge as broadly educated, technically sound aerospace engineers who will become future leaders in a critical industry

Department of Aerospace Engineering

229 Hammond Building

The Pennsylvania State University

University Park, PA 16802

Phone: 814-865-2569