A full-span free-wake model using circular-arc vortex elements and incorporating rotor trim analysis
A full-span free-wake model using circular-arc vortex elements and incorporating rotor trim analysis
An analytical method incorporating a free-wake analysis with a rotor trim algorithm is developed for predicting rotor wake geometry and blade loading distribution for a helicopter in hover and forward flight. The wake model of this method is based on a multi-filament full-span free wake, using sophisticated circular-arc vortex elements. The blade model is based on the second-order lifting-line theory to improve the calculation of three-dimensional tip effects. A rotor trim method is given, based on the finite-difference approximation of the blade flapping motion and the trim Jacobian matrix. This is subsequently coupled into the free-wake model. In order to demonstrate the capability of the coupled method, comparisons between the calculated results and the available experimental data of the rotor blade flapping motion for a model rotor are presented covering conditions from hover through forward flight. The free-wake geometry and the blade loading distribution at a low advance ratio are calculated for the H-34 helicopter rotor, and the blade loading distribution is compared with both the measured data and calculated results on the basis of the undistorted wake.
free wake, vortex element, rotor, trim analysis, helicopter
145-163
Hu, G.H.
9bf88d97-8dcd-4f64-b982-8feb6f8d2e5a
Newman, S.J.
802c97ed-ea28-477f-8b1e-8e4f873c4281
April 2006
Hu, G.H.
9bf88d97-8dcd-4f64-b982-8feb6f8d2e5a
Newman, S.J.
802c97ed-ea28-477f-8b1e-8e4f873c4281
Hu, G.H. and Newman, S.J.
(2006)
A full-span free-wake model using circular-arc vortex elements and incorporating rotor trim analysis.
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 220 (2), .
(doi:10.1243/09544100G04704).
Abstract
An analytical method incorporating a free-wake analysis with a rotor trim algorithm is developed for predicting rotor wake geometry and blade loading distribution for a helicopter in hover and forward flight. The wake model of this method is based on a multi-filament full-span free wake, using sophisticated circular-arc vortex elements. The blade model is based on the second-order lifting-line theory to improve the calculation of three-dimensional tip effects. A rotor trim method is given, based on the finite-difference approximation of the blade flapping motion and the trim Jacobian matrix. This is subsequently coupled into the free-wake model. In order to demonstrate the capability of the coupled method, comparisons between the calculated results and the available experimental data of the rotor blade flapping motion for a model rotor are presented covering conditions from hover through forward flight. The free-wake geometry and the blade loading distribution at a low advance ratio are calculated for the H-34 helicopter rotor, and the blade loading distribution is compared with both the measured data and calculated results on the basis of the undistorted wake.
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Published date: April 2006
Keywords:
free wake, vortex element, rotor, trim analysis, helicopter
Identifiers
Local EPrints ID: 44003
URI: http://eprints.soton.ac.uk/id/eprint/44003
ISSN: 2041-3025
PURE UUID: d096816e-1a8b-4b29-bacc-b65da8cc59a3
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Date deposited: 07 Feb 2007
Last modified: 15 Mar 2024 08:59
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Contributors
Author:
G.H. Hu
Author:
S.J. Newman
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