Calculation of Rotor Blade-Vortex Interaction Airloads Using a Multiple-Trailer Free-Wake Model

10.2514/1.130 ◽  
2003 ◽  
Vol 40 (6) ◽  
pp. 1123-1130
Author(s):  
Joon W. Lim ◽  
Yung H. Yu ◽  
Wayne Johnson
Keyword(s):  
Rotor Blade ◽  
Vortex Interaction ◽  
Blade Vortex Interaction ◽  
Wake Model ◽  
Free Wake

Calculation of Rotor Blade-Vortex Interaction Airloads Using a Multiple-Trailer Free-Wake Model

2003 ◽  
Vol 40 (6) ◽  
pp. 1123-1130 ◽  
Author(s):  
Joon W. Lim ◽  
Yung H. Yu ◽  
Wayne Johnson
Keyword(s):  
Rotor Blade ◽  
Vortex Interaction ◽  
Blade Vortex Interaction ◽  
Wake Model ◽  
Free Wake

A modified near wake dynamic model for rotor analysis

1999 ◽  
Vol 103 (1021) ◽  
pp. 143-146 ◽  
Author(s):  
T. Wang ◽  
F. N. Coton
Keyword(s):  
High Resolution ◽  
Dynamic Model ◽  
Numerical Evaluation ◽  
Helicopter Rotor ◽  
Vortex Interaction ◽  
Near Wake ◽  
Blade Vortex Interaction ◽  
Wake Model ◽  
Induced Velocity

Abstract The Beddoes near wake model, developed for high resolution blade vortex interaction computations, enables efficient numerical evaluation of the downwash due to trailed vorticity in the near wake of a helicopter rotor. The model is, however, limited by the assumption that the near wake lies in the plane of the rotor and, in some cases, by its inability to accurately evaluate the induced velocity contribution from vorticity trailed from inboard blade sections. In this paper, modifications to the method are proposed which address these issues and allow it to be used with confidence over a wider range of rotor flows.

scholarly journals Impact of Tip-Vortex Modeling Uncertainty on Helicopter Rotor Blade–Vortex Interaction Noise Prediction

2021 ◽  
Vol 66 (1) ◽  
pp. 1-13
Author(s):  
Stavros Vouros ◽  
Ioannis Goulos ◽  
Calum Scullion ◽  
Devaiah Nalianda ◽  
Vassilios Pachidis
Keyword(s):  
Vortex Core ◽  
Numerical Procedure ◽  
Tip Vortex ◽  
Analytical Models ◽  
Aerodynamic Noise ◽  
Helicopter Rotor ◽  
Vortex Interaction ◽  
Blade Vortex Interaction ◽  
Free Wake ◽  
The Impact

Free-wake models are routinely used in aeroacoustic analysis of helicopter rotors; however, their semiempiricism is accompanied with uncertainty related to the modeling of physical wake parameters. In some cases, analysts have to resort to empirical adaption of these parameters based on previous experimental evidence. This paper investigates the impact of inherent uncertainty in wake aerodynamic modeling on the robustness of helicopter rotor aeroacoustic analysis. A free-wake aeroelastic rotor model is employed to predict high-resolution unsteady airloads, including blade–vortex interactions. A rotor aeroacoustics model, based on integral solutions of the Ffowcs Williams–Hawkings equation, is utilized to calculate aerodynamic noise in the time domain. The individual analytical models are incorporated into an uncertainty analysis numerical procedure, implemented through nonintrusive Polynomial Chaos expansion. The potential sources of uncertainty in wake tip-vortex core growth modeling are identified and their impact on noise predictions is systematically quantified. When experimental data to adjust the tip-vortex core model are not available the uncertainty in acoustic pressure and noise impact at observers dominated by blade–vortex interaction noise can reach up to 25% and 3.50 dB, respectively. A set of generalized uncertainty maps is derived, for use as modeling guidelines for aeroacoustic analysis in the absence of the robust evidence necessary for calibration of semiempirical vortex core models.

Rotor blade-vortex interaction impulsive noise source localization

AIAA Journal ◽  
1990 ◽  
Vol 28 (4) ◽  
pp. 593-600 ◽  
Author(s):  
W. R. Splettstoesser ◽  
K. J. Schultz ◽  
Ruth M. Martin
Keyword(s):  
Source Localization ◽  
Rotor Blade ◽  
Noise Source ◽  
Impulsive Noise ◽  
Vortex Interaction ◽  
Blade Vortex Interaction
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