Fifth-Generation Target Drone Project Phase II

摘要

The Fifth Generation Target Study (5GTS) was a conceptual design task for a large target drone aircraft capable of representing key 5th generation fighter signature and performance attributes. The target drone's intended uses are to test air-to-air and surface-to-air missiles, and to ensure that modern tracking systems are capable of identifying and targeting 5th generation fighters. In Phase II of the conceptual design process, wind tunnel testing of a diamond wing candidate 5GTS configuration in the United States Air Force Academy Subsonic Wind Tunnel yielded poor stability characteristics. As a result, a series of modifications to the basic configuration were tested. These included a sweep study with wing sweeps varying from 30 degrees to 55 degrees, a wing planform study comparing diamond, trapezoid, delta, and W-shaped wings, and a tail study comparing 4-post and butterfly tails. In the end, 45 different concepts were tested and four promising configurations were selected for further study. These four included a delta-wing design with 50 degrees of sweep, an F-22-like configuration with a 42-degree-swept trapezoid wing, a tailless delta wing design using the 42-degree-swept wing, and a tailed design with W-planform wing with zigzag trailing edges parallel to the wing leading edges. A wind tunnel entry with 1/7 scale models of these four configurations and subsequent wind tunnel tests with smaller models further narrowed the field to just the 50-degree delta and the F-22-like configuration. Preliminary design of representative internal structures for each configuration provided refined estimates for structural weight and center of gravity as well as improved understanding of strengths and weaknesses of alternative structural design and fabrication strategies.