Trailing Vortex Wind-Tunnel Diagnostics with a Laser Velocimeter

Orloff, K. L.

doi:10.2514/3.60371

Cited by 40 publications

(12 citation statements)

References 13 publications

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“…(25) and (26) share the same integral of inlet conditions at the wing trailing edge. This inlet integral is found from Eq.…”

Section: T[p + Pul] Ds = I [P + Pu 2 ] Ds + Side Forces (26) Turbulenmentioning

confidence: 95%

“…Thus, subtracting Eq. (25) from Eq. (26) and neglecting the side force terms, which are approximately equal to each other for small radius changes, gives…”

Section: T[p + Pul] Ds = I [P + Pu 2 ] Ds + Side Forces (26) Turbulenmentioning

confidence: 98%

“…In summary form, the axial momentum balance during the inviscid rollup process is given by inlet ' = / [p + P" 2 ] dS + side forces inviscid vortex (25) The side forces and the outlet face forces and fluxes are readily calculated from the inviscid solution already obtained. Therefore, the integral of forces and fluxes on the inlet face can be determined from Eq.…”

Section: Viscous Core Conservation Lawsmentioning

confidence: 99%

“…1 " 9 More recently, blade-tip trailing vortex structure has been found to be critical to the accurate calculation of bladevortex interaction (B VI) noise in rotorcraft aeroacoustics. 1()~16 Trailing vortex formation has been examined both experimentally 17 " 25 and computationally. 26 " 28 The theoretical basis for the present vortex model lies with the Betz method for vortex sheet rollup, 29 which relates circulation in an axisymmetric trailing vortex to bound circulation on a generating wing.…”

Section: Introductionmentioning

confidence: 99%

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Prediction of Viscous Trailing Vortex Structure from Basic Loading Parameters

Rule

Bliss

1998

AIAA Journal

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An analytical method has been developed to predict the structure of a fully developed trailing vortex with a viscous core. Vortex structure is calculated from the load distribution on the generating wing and fundamental conservation laws are satisfied. The present rollup model implicitly addresses viscous effects in the vortex core region by assuming a turbulent mixing process in the core during formation. Mixing theory suggests the appropriate functional form of the solution velocity profiles within this region, with constants that are determined uniquely by the method for arbitrary wing loading distributions. Important structural properties such as vortex strength, core size, and peak swirl velocity are calculated directly from these solution constants. The viscous core model was validated against two recent experimental studies, which provided new insight into vortex growth. NomenclatureAI = shooting parameter C L = coefficient of lift i, ^2, G\, GI -auxiliary functions m = core axial velocity power law p = pressure Poo = freestream pressure R = core radius ratio, r s /r t r = vortex radius r c = vortex outer radius: complete inviscid rollup r in = streamtube inlet radius r p -vortex outer radius: partial inviscid rollup r s = solid body region outer radius r t = turbulent core radius s = span of rollup region (wing semispan) UQQ = freestream velocity u = vortex axial velocity v = vortex swirl velocity a = wing geometric angle of attack F = bound circulation F max = maximum bound circulation f = vortex circulation 6 = dimensionless wing loading strength £ = spanwise coordinate (from tip) f = centroid of vorticity Subscripts and Superscript i = initial condition t = value on turbulent core boundary = dimensionless quantity

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“…(25) and (26) share the same integral of inlet conditions at the wing trailing edge. This inlet integral is found from Eq.…”

Section: T[p + Pul] Ds = I [P + Pu 2 ] Ds + Side Forces (26) Turbulenmentioning

confidence: 95%

“…Thus, subtracting Eq. (25) from Eq. (26) and neglecting the side force terms, which are approximately equal to each other for small radius changes, gives…”

Section: T[p + Pul] Ds = I [P + Pu 2 ] Ds + Side Forces (26) Turbulenmentioning

confidence: 98%

Section: Viscous Core Conservation Lawsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Prediction of Viscous Trailing Vortex Structure from Basic Loading Parameters

Rule

Bliss

1998

AIAA Journal

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“…3 " 10 At the time of planning for the present work the only set of measurements behind wings representative of current transport aircraft were those of Chigier and Corsiglia 7 in which hot-wire measurements were made behind a CV-990 model wing. However, the measurements were affected by vortex meander 9 which resulted from the high turbulence level in the working section of the wind tunnel used.…”

Section: Introductionmentioning

confidence: 99%

Wind Tunnel Measurements of Rolling Moment in a Swept-Wing Vortex Wake

El-Ramly

Rainbird

Earl

1976

Journal of Aircraft

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Some measurements of the trailing vortex system behind a 35° sweptback, tapered wing have been made in a low-speed tunnel at a chord Reynolds number of 0.5 x 10 6 . Detailed wing loading was obtained from pressure distributions. Mean flow properties have been measured, using a non-nulling 5-hole probe, at two stations 2Vi and 5 main wing spans downstream. Induced rolling moment on two trailing wings, which intercepted the mainwing vortex system, was also measured. Judged by the circulation around the core, the shear layers had not fully rolled up at the 2Vib station. Also no further appreciable roll-up occurred at the 5b station. Furthermore, there was very little difference between the induced rolling moments measured at the two stations.

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Laser Doppler Anemometer Diagnostics in Unsteady Flows

Orloff

1978

Proceedings of the Dynamic Flow Conference 1978 on Dynamic Measurements in Unsteady Flows

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Trailing Vortex Wind-Tunnel Diagnostics with a Laser Velocimeter

Cited by 40 publications

References 13 publications

Prediction of Viscous Trailing Vortex Structure from Basic Loading Parameters

Prediction of Viscous Trailing Vortex Structure from Basic Loading Parameters

Wind Tunnel Measurements of Rolling Moment in a Swept-Wing Vortex Wake

Laser Doppler Anemometer Diagnostics in Unsteady Flows

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