To simulate a realistic plume from a helicopter exhaust, it is sometimes necessary to provide a downwash from the rotor blades. S & C have developed a series of 168 Coanda ringjet ejectors which are fed from the Gnome turboshaft 1 compressor flow. These ejectors allow jets of compressor flow to entrain large quantities of ambient air and turn through 90 degrees, resulting in a large downwash footprint. The rig can to flight stream rig allows a simulation of propulsion systems under dynamic testing. The system uses the compressed air flow from the Gnome turboshaft rigs, which is fed through a twin ejector system to entrain large amounts of ambient air. This is settled in a large plenum chamber before it exits via a large nozzle which comprises the working section.

Specifications

• Average downwash velocity 12.52m/s
• Max temperature 14.3ºC above ambient (1m below nozzle exit)
• Turbulence levels approx 20%
• Working area 2.4 x 1.35m
• Adjustable height above test article

Applications

• Rotor blade flow
• Tailwind or side wind