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Aircraft Flutter Testing
When activated, the DEI Flutter Exciter alternately slogan for Dynamic Engineering Inc. (DEI) is deflects the airstream upward and downward in a rapid "mobilizing minds and materials in research and manner, creating a force similar to that produced by an development for land, sea, air, and space." That oscillating trailing edge flap. Because the system runs on blend of talent and technology came together in 1972 to very little electrical power, rather than tapping into an establish DEI of Newport News, Virginia. The core of aircraft's hydraulic system, several benefits are realized.
early work by the company was building aircraft models Among them, because the DEI flutter components are a for wind tunnel testing at Langley ~ese&ch Center.
"strap-on" type of hardware, cost and complexity of During his 34-year employment at Langley, Wilmer fitting the system on the aircraft can be lessened. The Reed gained international recognition for his innovative research, contributions and patented ideas relating to DEI Exciter is readily adaptable to a variety of aircraft. It flutter and aeroelasticity of aerospace vehicles. In the is effective on all fued wing and rotorcraft applications, early 1980s, Reed retired from Langley to join the from single-seater to airliner-sized vehicles.
engineering staff of DEI. While at DEI, Reed recognized DEI sub-scale flutter exciters are also available to the need to increase the safety and minimize the cost incorporate into wind tunnel flutter models, permitting and hazards associated with aircraft flight flutter testing. an aircraft builder to pre-qualify a vehicle design.
He thus conceived and patented the DEI Flutter Exciter, In recent years, DEI used its skills to fabricate a now used world wide in flight flutter testing of new or complete set of fan blades for the National Transonic modified aircraft designs. Facility (NTF) at Langley. DEI has applied its ideas on The Flutter Exciter system provides dynamic force suspension techniques to NASA work on large, flexible input to stimulate structural vibration modes of an space structures. More than 1,000 tasks have been aircraft in flight, and through a l l its flying conditions. completed for Langley alone. Employed by NASA This innovative product generates programmed sinusoi- Ames-Dryden, the employee-owned group was also dal forces at controllable frequencies, amplitudes, phases contracted to work on NASKs F-1GXL flight test and sweep durations. By inducing these forces, structural program.
vibrations on the aircraft can be damped. Twenty-five years after creation, DEI has grown to The DEI Flutter Exciter is controlled directly by the several hundred employees with $20 million in annual sales and has expanded its aerodynamic analysis tech- pilotloperator through a digital Cockpit Control Box niques to justify its company claim: "Where imagination and Avionics Box electronics and software. The Exciters takes shape."
are powered by DC servo motors through interconnect- ing cables. Small fued vanes are mounted at the wing tips and tail tips of an aircraft.
Dynamic Engineering Znc. 5 Flutter Exciter mounts at the wing tips and tail tips of an aircraft to damp out structural vibrations.