Transonic Free-To-Roll Analysis of the F/A-18E and F-35 Configurations

Owens, D. Bruce; McConnell, Jeffrey K.; Brandon, Jay M.; Hall, Robert M.

doi:10.2514/6.2004-5053

“…The static and FTR testing were both done in the NASA Langley 12-Foot Low-Speed Tunnel. The experiments were conducted at sea-level pressure and density with a freestream dynamic pressure of 4 psf resulting in a mean aerodynamic chord-based Reynolds number of 0.5X10 6 . Although numerous configurations were tested, the paper will present LEX vents closed and LEX vents open with the LEF = 10', TEF = 30', and ailerons = 300 (symmetric trailing-edge-down deflection).…”

Section: Experimental Approachmentioning

confidence: 99%

Free-to-Roll Investigation of the Pre-Production F/A-18E Powered Approach Wing Drop

Owens¹,

Bryant²,

Barlow³

2005

0

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Public reporting burden for this collectitli If ?i'ormjtion is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. AUTHOR(S)CAPT BRYANT ELAINE M A free-to-roll study of the low-speed lateral characteristics of the pre-production F/A-18E was conducted in the NASA Langley 12-Foot Low-Speed Tunnel. In developmental flight tests the F/A-18E unexpectedly experienced uncommanded lateral motions in the power approach configuration. The objective of this study was to determine the feasibility of using the free-to-roll technique for the detection of uncommanded lateral motions for the preproduction F/A-18E in the power approach configuration. The data revealed that this technique in conjunction with static data revealed insight into the cause of the lateral motions. The free-to-roll technique identified uncommanded lateral motions at the same angle-of-attack range as experienced in flight tests. The cause of the uncommanded lateral motions was unsteady asymmetric wing stall. The paper also shows that free-to-roll data or static force and moment data alone are not enough to accurately capture the potential for an aircraft to experience uncommanded lateral motion. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

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“…28 The work was also conducted for the scaled-down F/A-18E to analyze the effect of configuration changes at transonic speeds. 29 Subsequently, wing-body rock for four military aircrafts, such as the F-16c and the F/A-18C were analyzed; 30,31 the results showed that the rolling motions had nonzero mean roll angles. In addition, the works of Williams et al also confirmed this property of x-31.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of wing-body rock with nonzero equilibrium roll angles

Wei

¹

,

Shi

²

,

Geng

³

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part G:

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To study wing-body rock, various tests were used for the canard-configuration models in the wind tunnel, including free rolling, disturbance on free rolling, static moment measurements, dynamic derivative measurements, smoke wire method and particle image velocimetry. The models also have a chine forebody, strake wings, main wings and a vertical tail. In the tests, the canard deflection angles are 0° and 20° relative to the axis of the body. First, the roll angle time histories were obtained by free rolling motion and disturbed motion; the results demonstrate that both canard-configuration models have nonzero mean roll angles. In particular, the existence of the other larger nonzero mean roll angles on the same side is a curious aspect at the critical pitch angle, such as at θ = 37° for the model with canard deflection of 20°. Next, static moment tests and dynamic derivative tests demonstrate that although the roll angle time histories are non-limit cycle motions, they are irregularly self-excited oscillation under the influence of multi-vortex structures. Finally, the constituent parts of structures over wing bodies and the flow mechanism of abruptly jumping from an equilibrium roll angle to the other on the same roll side were revealed by the smoke wire and particle image velocimetry measurements.

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“…The classical FTR test technique offered promise for shedding additional light on the flight dynamics and aerodynamics of the lateral motions of the vents-open and vents-closed pre-production F/A-18E configurations. Owens et al 5 ' 6 reported on an extensive study of transonic uncommanded lateral motions of military aircraft using the free-to-roll technique, including the pre-production F/A-18E. The motivations, methods, and objectives for the application of the FTR method to the PA configuration parallel those for the transonic FTR tests of the pre-production F/A-1 8E.…”

Section: This Paper Is Declared a Work Of The Us Government And Is mentioning

confidence: 99%

“…In order to quantify the lateral activity a FOM was used similar to the one developed by Owens et al 5 ' 6 . The FOM is calculated from the roll-angle time histories and captures amplitude and rate effects.…”

Section: B Free To Roll Testingmentioning

confidence: 99%

“…The static and FTR testing were both done in the NASA Langley 12-Foot LowSpeed Tunnel. The experiments were conducted at sea-level pressure and density with a freestream dynamic pressure of 4 psf resulting in a mean aerodynamic chord-based Reynolds number of 0.5X10 6 . Although numerous configurations were tested, the paper will present LEX vents closed and LEX vents open with the LEF = 10', TEF = 30', and ailerons = 300 (symmetric trailing-edge-down deflection).…”

Section: Experimental Approachmentioning

confidence: 99%

See 1 more Smart Citation

Free-to-Roll Investigation of the Preproduction F/A-18E Powered-Approach Wing Drop

Owens

¹

,

Bryant

²

,

Barlow

³

2006

Journal of Aircraft

Self Cite

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Public reporting burden for this collectitli If ?i'ormjtion is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. AUTHOR(S)CAPT BRYANT ELAINE M A free-to-roll study of the low-speed lateral characteristics of the pre-production F/A-18E was conducted in the NASA Langley 12-Foot Low-Speed Tunnel. In developmental flight tests the F/A-18E unexpectedly experienced uncommanded lateral motions in the power approach configuration. The objective of this study was to determine the feasibility of using the free-to-roll technique for the detection of uncommanded lateral motions for the preproduction F/A-18E in the power approach configuration. The data revealed that this technique in conjunction with static data revealed insight into the cause of the lateral motions. The free-to-roll technique identified uncommanded lateral motions at the same angle-of-attack range as experienced in flight tests. The cause of the uncommanded lateral motions was unsteady asymmetric wing stall. The paper also shows that free-to-roll data or static force and moment data alone are not enough to accurately capture the potential for an aircraft to experience uncommanded lateral motion. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

show abstract

Transonic Free-To-Roll Analysis of the F/A-18E and F-35 Configurations

Cited by 15 publications

References 17 publications

Free-to-Roll Investigation of the Pre-Production F/A-18E Powered Approach Wing Drop

Free-to-Roll Investigation of the Pre-Production F/A-18E Powered Approach Wing Drop

Experimental investigation of wing-body rock with nonzero equilibrium roll angles

Free-to-Roll Investigation of the Preproduction F/A-18E Powered-Approach Wing Drop

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