Design, Fabrication, Testing, And Data Analysis Of Adam II Concept (Propulsive Wing). Part II. Shakedown Testing In Vad 7-Ft X 10-Ft Low Speed Wind Tunnel
Report Number: AFFDL TR 68-31 Part 2
Author(s): Meyer, Robert D., English, Robert B., Davidson, Jim K.
Corporate Author(s): LTV Aerospace Corp Dallas Tx Vought Aeronautics Div
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1968-05
Pages: 54
Contract: AF 33(615)-3293
DoD Project: 1366
DoD Task: 136617
Identifier: AD0832604
Abstract:
An analysis is presented of the data obtained from a short series of tests to "shakedown" a powered model of the ADAM II V/STOL concept. Correlating data from tests of a related semispan model are also included. Results show that the longitudinal stability of the present configuration in the cruise mode has a greater nariation with angle of attack and power than conventional airplanes. The data indicated that, for this test, possible lower surface flap separation and detached nose fan exit flow caused nonlinearities in pitching moment. These can be eliminated by redesign at critical points to provide good stability. The location of the horizontal tails in the wing tip vortex results in an upwash derivative (negative d(espilon)/d(alpha)) that results in a high level of horizontal tail contribution to stability. Although the basic low aspect ration horizontal tails were highly loaded and operating wih disturbed flow conditions much of the time, there was no indication of tail stall. Horizontal tail control effectiveness appears to be adequate at the present stability levels. The model was less stable directionally than longitudinally in the sense that a greater forward movement in c. g. location is required for neutral stability. In this test, directional stability was independent of angle of attack and power effects, and lateral stability was at all times positive and varied with angle of attack and power effects.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Meyer, Robert D., English, Robert B., Davidson, Jim K.
Corporate Author(s): LTV Aerospace Corp Dallas Tx Vought Aeronautics Div
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1968-05
Pages: 54
Contract: AF 33(615)-3293
DoD Project: 1366
DoD Task: 136617
Identifier: AD0832604
Abstract:
An analysis is presented of the data obtained from a short series of tests to "shakedown" a powered model of the ADAM II V/STOL concept. Correlating data from tests of a related semispan model are also included. Results show that the longitudinal stability of the present configuration in the cruise mode has a greater nariation with angle of attack and power than conventional airplanes. The data indicated that, for this test, possible lower surface flap separation and detached nose fan exit flow caused nonlinearities in pitching moment. These can be eliminated by redesign at critical points to provide good stability. The location of the horizontal tails in the wing tip vortex results in an upwash derivative (negative d(espilon)/d(alpha)) that results in a high level of horizontal tail contribution to stability. Although the basic low aspect ration horizontal tails were highly loaded and operating wih disturbed flow conditions much of the time, there was no indication of tail stall. Horizontal tail control effectiveness appears to be adequate at the present stability levels. The model was less stable directionally than longitudinally in the sense that a greater forward movement in c. g. location is required for neutral stability. In this test, directional stability was independent of angle of attack and power effects, and lateral stability was at all times positive and varied with angle of attack and power effects.
Provenance: Lockheed Martin Missiles & Fire Control