USB environment assessment based on YC-14 flight test measurements

Sussman, M. B.; Reed, Jim; O’Keefe, John A.; Eldridge, W.

doi:10.2514/6.1977-593

Cited by 2 publications

(6 citation statements)

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“…At this point, the moment can be transferred to the quarter chord location as: (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) This completes the current use of the jet-flap theory. Since it is based on 2-D thin airfoil theory (note that all the previous equations reduce to the classic formulas when there is no blowing) no drag force can be predicted from the theory.…”

Section: -Pitching Moment Coefficientmentioning

confidence: 96%

“…Using the definition of Γ PV solved for V exit at R ref : Re-arranging this to get a delta pressure on the LHS, then normalizing by the jet dynamic pressure to get a pressure coefficient, we obtain the final 2 equations: Comparison was also done with data published by Sussman (8) from the YC-14 flight test program. Although the geometry data isn't presented well in this paper, some data can be inferred from knowledge of the YC-14.…”

Section: -Derivation Of Circular Streamline Theory For Usbmentioning

confidence: 99%

“…(4-11), (4)(5)(6)(7)(8)(9)(10)(11)(12) In the case of a trailing edge flap with a jet, the pitching moment's angle of attack relationship will remain the same, but the change due to the aft flap must be accounted for. A superposition of the classical flap contribution and the additional effects of the jet deflection leads to:…”

Section: -Pitching Moment Coefficientmentioning

confidence: 99%

“…This method would be relatively simple and could be applied without solving for the velocity of the entire flowfield. To check this model, figures will be presented showing comparisons with published surface pressure data from Davenport (24) and Sussman (8) . Davenport, in fact, did include a small amount of work with Circular Streamline Theory in his analysis and demonstrated that circular streamline theory can provide reasonable estimates of the surface pressure.…”

Section: -Circular Streamline Theorymentioning

confidence: 99%

“…They have the additional benefit of shielding the engine noise above the wing and away from the ground (8) . This technology has been successfully demonstrated in the past on experimental and research aircraft.…”

Section: Chapter 1: Introductionmentioning

confidence: 99%

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A Conceptual Design Methodology for Predicting the Aerodynamics of Upper Surface Blowing on Airfoils and Wings

Keen

2005

23rd AIAA Applied Aerodynamics Conference

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One of the most promising powered-lift concepts is Upper Surface Blowing (USB), where the engines are placed above the wing and the engine exhaust jet becomes attached to the upper surface. The jet thrust can then be vectored by use of the trailing edge curvature since the jet flow tends to remain attached by the "Coanda Effect". Wind tunnel and flight-testing have shown USB aircraft to be capable of producing maximum lift coefficients near 10. They have the additional benefit of shielding the engine noise above the wing and away from the ground.Given the potential gains from USB aircraft, one would expect that conceptual design methods exist for their development. This is not the case however. While relatively complex solutions are available, there is currently no adequate low-fidelity methodology for the conceptual and preliminary design of USB or USB/distributed propulsion aircraft. The focus of the current work is to provide such a methodology for conceptual design of USB aircraft. Based on limited experimental data, the new methodology is shown to compare well with wind tunnel data.In this thesis we have described the new approach, correlated it with available 2-D data, and presented comparisons of our predictions with published USB data and an existing non-linear vortex lattice method. The current approach has been shown to produce good results over a broad range of propulsion system parameters, wing geometries, and flap deflections. In addition, the semi-analytical nature of the methodology will lend itself well to aircraft design programs/optimizers such as ACSYNT. These factors make the current method a useful tool for the design of USB and USB/distributed propulsion aircraft.iii

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