Prediction of Blade-Vortex Interaction Airloads With Higher-Harmonic Pitch Controls Using the 2GCHAS Comprehensive Code

2001 ◽  
Vol 123 (4) ◽  
pp. 469-474 ◽  
Author(s):  
Joon W. Lim ◽  
Chee Tung ◽  
Yung H. Yu
Keyword(s):  
Tip Vortex ◽  
Vortex Interaction ◽  
Main Rotor ◽  
Scaled Model ◽  
Harmonic Control ◽  
Blade Vortex Interaction ◽  
Higher Harmonic Control ◽  
Blade Tip ◽  
Higher Harmonic ◽  
Analysis System

Analytically predicted results of blade-vortex interaction (BVI) airloads, using the second- generation comprehensive helicopter analysis system (2GCHAS), are presented with the experimental results obtained from the higher-harmonic-control aeroacoustic rotor test (HART) program using a 40-percent, Mach-scaled model of the hingeless BO-105 main rotor. Correlations include airloads, blade tip deflections, and tip vortex geometry. The effects on blade airload predictions are studied with higher-harmonic pitch controls (HHC). It was concluded that the blade torsional deflection and the wake system play a very important role in predicting BVI airloads.

Analysis of a higher harmonic control test to reduce blade vortex interaction noise

1994 ◽  
Vol 31 (6) ◽  
pp. 1341-1349 ◽  
Author(s):  
Thomas F. Brooks ◽  
Earl R. Booth ◽  
D. Douglas Boyd ◽  
Wolf R. Splettstoesser ◽  
Klaus J. Schultz ◽  
...  
Keyword(s):  
Control Test ◽  
Vortex Interaction ◽  
Harmonic Control ◽  
Blade Vortex Interaction ◽  
Higher Harmonic Control ◽  
Higher Harmonic

Fundamental investigation using active plasma control to reduce blade–vortex interaction noise

2021 ◽  
pp. 1475472X2110526
Author(s):  
Trushant K Patel ◽  
Alexander J Lilley ◽  
Weiqi Shen ◽  
Christian Porrello ◽  
Alexander Schindler-Tyka ◽  
...  
Keyword(s):  
Rotor Blades ◽  
Tip Vortex ◽  
Plasma Actuators ◽  
Supporting Evidence ◽  
Vortex Interaction ◽  
Dominant Component ◽  
Fundamental Investigation ◽  
Blade Vortex Interaction ◽  
Aerial Vehicle ◽  
Blade Tip

Blade vortex interaction noise is a problematic and dominant component of rotor noise. Plasma actuators strategically placed at the tip of the rotor blades can reduce the strength of the tip vortices. This reduction has the potential to significantly reduce blade vortex interaction noise. A combined experimental, numerical, and theoretical program shows supporting evidence that low power plasma actuators can effectively lower coherence of the blade tip vortex and reduce blade vortex interaction noise over-pressure by up to 80%. For a nominal small five-bladed unmanned aerial vehicle, we predict an approximate 8.88 maximum ΔdB reduction for a 150 m/s tip speed. Experimental, computational, and acoustic modeling support these predictions. This study represents a fundamental investigation in the fixed-frame, which provides evidence for higher level research and testing in a rotating framework.

Effects of higher harmonic control on rotor performance and control loads

1992 ◽  
Vol 29 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Khanh Nguyen ◽  
Inderjit Chopra
Keyword(s):  
Harmonic Control ◽  
Higher Harmonic Control ◽  
Higher Harmonic ◽  
And Control

A Higher Harmonic Control Test in the DNW to Reduce Impulsive BVI Noise

1994 ◽  
Vol 39 (4) ◽  
pp. 3-13
Author(s):  
Wolf R. Splettstoesser ◽  
Klaus‐J. Schultz ◽  
Roland Kube ◽  
Thomas F. Brooks ◽  
Earl R. Booth ◽  
...  
Keyword(s):  
Control Test ◽  
Harmonic Control ◽  
Higher Harmonic Control ◽  
Higher Harmonic
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