Historically, GRE designs placed square walls around the aircraft with little regard for aerodynamic performance. Jet blast was deflected using porous screens or integrated sloped rear walls. This resulted in a GRE that could be used successfully in only extremely limited wind conditions due to turbulence at the engine inlet, which can lead to dangerous stalls and surges. The acoustical benefits of a GRE are lost if an aircraft cannot use a facility in diverse wind conditions.
BDI's revolutionary ground run-up enclosures are suitable for all aircraft including the A380, B-777, and B-787. The combination of the aerodynamically advanced Stabile Flow™ design with the effectiveness of Noiseblotter™ acoustic panels provides a stable, effective GRE with very high usability and noise reduction.
Recognizing the aerodynamic issues affecting successful high power run-ups within acoustic enclosures, BDI began an extensive development program using scale and computer modeling to develop a new approach in GRE technology. The resulting Stabile Flow™ design drastically improves GRE usability in adverse wind conditions.
By reducing vortex formation at the walls, pressure buildup at the rear of the aircraft, and inlet pressure drops, the Stabile Flow™ system assures appropriate flow conditions are maintained at the engine inlet and that exhaust recirculation is minimized.
BDI's patented Noiseblotter™ panels were designed specifically for control of the low frequency noise generally associated with aircraft ground run-ups. They feature a high transmission loss (STC) of 36 and effective absorption of low frequency noise. These panels have a demonstrated noise reduction coefficient (NRC) of 1.25 and maintain an absorption coefficient of 1.0 at 100 Hz. The use of non-hydroscopic materials and acoustically transparent wrap materials assures a long, maintenance-free life.