Velocity measurements of airframe effects on a rotor in a low-speed forward flight

Liou, S. G.; Komerath, Narayanan; McMahon, Howard M.

doi:10.2514/3.45766

Cited by 38 publications

(19 citation statements)

References 4 publications

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“…The vorticity field was constructed from measurements of twocomponents of velocity individually measured in the plane. These measurements were made in 1986 by Liou (21). Here positive numbers indicate clockwise vorticity.…”

Section: Resultsmentioning

confidence: 99%

Measurements of the near wake of a rotor in forward flight

Mahalingam

Komerath

1998

36th AIAA Aerospace Sciences Meeting and Exhibit

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ABSTRACT# Graduate Research Assistant, Student Member AIAA * Professor, Associate Fellow AIAA This paper describes initial measurements of the near wake of a 2-bladed teetering, untwisted, squaretipped rotor in forward flight. Issues of periodicity and repeatibility of the core are studied using laser velocimetry and flow-visualization on the front of the rotor wake where cycle to cycle variations are expected. Core passage uncertainty from cycle to cycle is less than 1 of rotor azimuth. Velocity measurements on the advancing blade side show wake-like core-axial velocities higher than the core circumferential velocity for the first 180 of vortex age. Both the axial and circumferential velocities approach 50% of blade tip speed. The inboard vortex sheet has substantial wake-like velocities and rolls up into a concentrated circulatory region of high wake-like axial velocity rotating opposite to the tip-vortex, within 30 from the blade. The fullydeveloped values of the vortex core circulation, radius and axial velocity remain constant over 180 of age as current measurements indicate. Measurements on the front, rear and retreating blade side of the rotor are in progress.

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Section: Resultsmentioning

confidence: 99%

Measurements of the near wake of a rotor in forward flight

Mahalingam

Komerath

1998

36th AIAA Aerospace Sciences Meeting and Exhibit

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“…Unsteady and timeaveraged flow behavior and fuselage surface pressure measurements were conducted at Georgia Tech for a generic cylindrical airframe under a two-bladed rotor system in forward flight. 10,11) Experimental results have also been reported for a generic fuselage configuration in the form of fuselage surface pressure distribution and inflow at the rotor disk plane. [12][13][14] In the present study, an attempt is made for the prediction of rotor-fuselage interactional aerodynamic problems, using a 3-D Euler solver based on unstructured meshes.…”

Section: Introductionmentioning

confidence: 99%

“…It is shown that the rotor disk is represented by several triangles, as explained earlier. To validate the time-averaged rotor disk modeling of the present method, the inflow distribution beneath the rotor is compared with the experiment 10) at four azimuthal positions of the rotor in Fig. 6.…”

Section: Georgia Tech Configurationmentioning

confidence: 99%

“…The first case, which has a two-bladed rotor and a generic cylindrical fuselage configuration, was tested at Georgia Tech. 10,11) The second validation is made for the configuration tested at the NASA Langley Research Center with a more realistic configuration known as ROBIN (ROtor Body INteraction) fuselage. [12][13][14] Calculations are made for both fuselage-alone and rotor-fuselage configurations.…”

Section: Computational Detailsmentioning

confidence: 99%

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Predicting Aerodynamic Rotor-Fuselage Interactions by Using Unstructured Meshes

Lee¹,

Kwon

2002

Trans. Japan Soc. Aero. S Sci.

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A numerical method has been developed for the analysis of interactional aerodynamics between helicopter rotor and fuselage in forward flight. A 3-D steady compressible Euler solver is used to compute time-averaged interactional effects between the rotor and the fuselage. The rotor is modeled as an actuator disk with zero thickness carrying pressure jump across it. Collective and cyclic pitch angles are calculated to satisfy the rotor trim condition. Unstructured meshes are used to model complex rotor-fuselage configurations. Calculations are performed for two generic helicopter fuselage geometries. The results are compared with available experimental data for validation.

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“…The second validation of the present method was made for the rotor-fuselage configuration tested at Georgia Tech [18,19]. This configuration consisted of a two-bladed teetering rotor and a generic cylinderical fuselage.…”

Section: Rotor-fuselage Configurationmentioning

confidence: 99%

Numerical Simulation of Unsteady Rotor Flow Using an Unstructured Overset Mesh Flow Solver

Jung¹,

Kwon²

2009

International Journal of Aeronautical and Space Sciences

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An unstructured overset mesh method has been developed for the simulation of unsteady flow fields around isolated rotors and rotor-fuselage configurations. The flow solver was parallelized for the efficient calculation of complicated flows requiring a large number of cells. A quasi-unsteady mesh adaptation technique was adopted to enhance the spatial accuracy of the solution and to better resolve the rotor wake. The method has been applied to calculate the flow fields around rotor-alone and rotor-fuselage configurations in forward flight. Validations were made by comparing the predicted results with those of measurements. It was demonstrated that the present method is efficient and robust for the prediction of unsteady time-accurate flow fields involving multiple bodies in relative motion.

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Velocity measurements of airframe effects on a rotor in a low-speed forward flight

Cited by 38 publications

References 4 publications

Measurements of the near wake of a rotor in forward flight

Measurements of the near wake of a rotor in forward flight

Predicting Aerodynamic Rotor-Fuselage Interactions by Using Unstructured Meshes

Numerical Simulation of Unsteady Rotor Flow Using an Unstructured Overset Mesh Flow Solver

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