Inlet development for the L- 500

Hancock, J. P.; Hinson, B. L.

doi:10.2514/6.1969-448

Cited by 2 publications

(2 citation statements)

References 1 publication

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“…To minimize the hazard brought by the crosswind, characteristics of the nacelle ow eld and corresponding nacelle optimization have been extensively carried out (Hancock et al 1969;Cesare et al 2015). These works are mainly based on wind tunnel tests, bench crosswind tests, and ight testing platforms.…”

Section: Introductionmentioning

confidence: 99%

Flow Separation Control of Nacelle in Crosswind by Microsecond Pulsed Surface Dielectric Barrier Discharge Plasma Actuator

Jia

Liang

et al. 2021

Flow Turbulence Combust

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Flow separation under crosswind conditions seriously jeopardizes the quality of the nacelle's ow eld. In this paper, microsecond pulsed surface dielectric barrier discharge (µSDBD) is used to suppress the ow separation and reduce the crosswind distortion of the nacelle. The ow structure induced by the µSDBD is rst explored by a high-speed schlieren system. The pressure waves composed of a cylindrical wave surrounding the electrodes and a at wave at the top of the cylindrical one can be perceived, which indicates the fast gas heating produced by the µSDBD. A set of wind tunnel tests are then conducted to verify the ability of µSDBD to suppress the nacelle ow separation and study the in uence laws of pulse frequency, coverage area, and the actuator layout on the ow control effects. Results show that plasma actuation can not only improve the total pressure at the exit of the nacelle but also suppress the ow distortion caused by the crosswind. The best ow control effect can be achieved at the pulse frequency of 500Hz, with the value of sectional distortion coe cient reduced by 57.76% compared with the baseline condition. The ow control effect with the plasma actuator covering 120° of the nacelle perimeter is better than that of 60° and 180° coverage, showing the highest ow control e ciency in the 120°c ondition. The µSDBD can improve mixing between the boundary layer and the main ow, enhancing the ability of the boundary layer to resist the adverse pressure gradient, which is bene cial to ow separation control.

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Section: Introductionmentioning

confidence: 99%

Flow Separation Control of Nacelle in Crosswind by Microsecond Pulsed Surface Dielectric Barrier Discharge Plasma Actuator

Jia

Liang

et al. 2021

Flow Turbulence Combust

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“…This resulted in the values of diffuser effective cone angle given in Figure 3 which are considered conservative. (7,8) Cowl surface contours from the cowl throat to the fan face were third order polynomials with the coefficients determined from the values of the cowl radii and slopes at the throat and fan face. The two spinners had NACA 1-Series contours (6), and projected to the throats of each cowl, resulting in the minimum duct area, AMIN, being slightly downstream of the cowl throats for three of the combinations of cowls and spinners, as indicated by comparison of AI/AT and AI/AMIN in Figure 3.…”

Section: Fan Engine Modelmentioning

confidence: 99%

Wind tunnel tests of a 20 inch diameter 1.15 pressure ratio fan engine model

Wesoky

Steffen

1973

9th Propulsion Conference

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Aerodynamic and acoustic measurements at a typical STOL aircraft takeoff and landing velocity demonstrated that a 1.35 inlet lip area contraction ratio was superior to a 1.26 ratio at high nacelle incidence angles. Reverse thrust, obtained with a . variable pitch rotor, was lower at the landing velocity, and the noise level higher, than at the static"condition. High speed tests showed that, for the design cruise Mach number of 0.75, internal losses and external drag were 27 percent of the ideal fan net thrust, and propulsive efficiency was 1 estimated to be 59 percent for an 85 percent efficient fan stage. For comparison, a similar 1.55 pressure ratio fan system would have a propulsive efficiency of 62 percent.

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Inlet development for the L- 500

Cited by 2 publications

References 1 publication

Flow Separation Control of Nacelle in Crosswind by Microsecond Pulsed Surface Dielectric Barrier Discharge Plasma Actuator

Flow Separation Control of Nacelle in Crosswind by Microsecond Pulsed Surface Dielectric Barrier Discharge Plasma Actuator

Wind tunnel tests of a 20 inch diameter 1.15 pressure ratio fan engine model

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