Smart Materials and Structures-Smart Wing. Volumes 1, 2, 3 and 4.

摘要

This final report of the DARPA-sponsored, Air Force Research Laboratory administered Smart Wing Phase 1 program documents key results and conclusions reached in the application of smart materials to both subsonic and transonic adaptive wing development. The program effort for the subsonic regime targeted an F/A-18 class vehicle, and examined (1) variable wing twist effected by a nickel titanium (NiTi) shape memory alloy (SMA) torque tube and (2) hingeless, smoothly contoured trailing edge control surface deployment using SMA wires. Two 16% scale wing wind tunnel models were fabricated, one with SMA actuated control surfaces and the other of conventional design, and tested at NASA Langley Research Center (LaRC). Up to and greater than a 10% increase in lift and rolling moment versus a conventional flap and aileron was demonstrated for the Smart Wing design. Program development for the transonic effort, on the other hand, was focused on commercial aircraft, and examined two approaches for gaining fuel savings by optimizing transonic cruise: (1) an adaptive wing that employed TERFENOL-D linear actuators in the wing box structure (between the spars) to optimize airfoil shape, and (2) camber modification with smoothly contoured trailing edge, also powered by a TERFENOL-D linear wave actuator. The latter approach was downselected and program studies showed that fuel savings of 5% were achievable equating to cost savings up to $7 billion per year for US-based commercial jet fleets. The work performed under this contract is being continued under an on-going Phase 2 effort. This work will be completed in early 2001 and is expected to lead to flight testing on unmanned aircraft, leading the way for near-term technology transition to operational flight vehicles.