Development and Validation of Generic Maneuvering Flight Noise Abatement Guidance for Helicopters

2021 ◽  
Author(s):  
James H. Stephenson ◽  
Michael E. Watts ◽  
Eric Greenwood ◽  
Kyle A. Pascioni
Keyword(s):  
Flight Test ◽  
Vortex Interaction ◽  
Noise Abatement ◽  
Maneuvering Flight ◽  
Blade Vortex Interaction ◽  
The Difference ◽  
Band Limited ◽  
Miss Distance ◽  
Development And Validation ◽  
Peak Value

An extensive flight-test campaign has been conducted to look into developing actionable advice for pilots of today's vehicles to reduce their acoustic footprints. Ten distinct vehicles were tested at three different test ranges, with nine of the vehicles' data being documented here. Twelve pairs of turning conditions were tested to determine their effect on blade–vortex interaction noise. Each turning flight condition was evaluated using the peak A-weighted, band-limited (50–2500 Hz), sound pressure level measured throughout the maneuver. This metric was a surrogate for blade–vortex interaction (BVI) noise, and the difference between the peak values of each turning pair was investigated. That peak value difference was subsequently corrected by the offset from the intended vehicle altitude at turn initiation from the actual altitude at initiation. The corrected amplitudes were investigated and grouped into six validated actionable guidance principles that can be given to pilots to immediately reduce their acoustic footprint during operations. This generic guidance works by keeping the rotor well away from the wake throughout the maneuver, thus increasing miss distance and reducing the occurrence of objectionable BVI noise.

Design and Simulation of Guidance Law for a Kind of Flight Test Missile

2012 ◽  
Vol 538-541 ◽  
pp. 2887-2891
Author(s):  
Yu Qian ◽  
Xiao Jun Xiang ◽  
Jun Li Yang
Keyword(s):  
Flight Test ◽  
Target Point ◽  
Impact Point ◽  
Integral Term ◽  
Guidance Law ◽  
Velocity Information ◽  
The Difference ◽  
Miss Distance ◽  
Midcourse Guidance ◽  
The Impact

To reduce the miss distance of flight test missile, the midcourse guidance law is studied in this paper. The nonlinear projectile dynamic model is developed at first, and then designed the midcourse guidance law with the impact point prediction information. The guidance law was designed using the difference between predicting impact point and target point. To improve the guidance law’s performance, this research inducted the predicted impact point’s velocity information and integral term into guidance law command. At the end, the simulation was developed. The results of simulation show that the guidance law designed in this study is successful and it can satisfy the test missile’s flight mission requirements.

A wind-tunnel based study of helicopter tail rotor blade vortex interaction

2004 ◽  
Vol 108 (1083) ◽  
pp. 237-244 ◽  
Author(s):  
F. N. Coton ◽  
R. A. McD. Galbraith ◽  
T. Wang ◽  
S. J. Newman
Keyword(s):  
Wind Tunnel ◽  
Rotor Blade ◽  
Tip Vortex ◽  
Vortex Interaction ◽  
Pressure Transducers ◽  
Control Effectiveness ◽  
Rotating Blade ◽  
Blade Vortex Interaction ◽  
Bladed Rotor ◽  
Development And Validation

AbstractThe interaction of a helicopter tail rotor blade with the tip vortex system from the main rotor is a significant source of noise and, in some flight states, can produce marked reductions in control effectiveness. This paper describes a series of wind-tunnel tests to simulate tail rotor blade vortex interaction with a view to providing data for the development and validation of numerical simulations of the phenomenon. In the experiments, which were carried out in the Argyll wind-tunnel of Glasgow University, a single-bladed rotor located in the tunnel’s contraction was used to generate the tip vortex which travelled downstream into the working section where it interacted with a model tail rotor. The tail rotor was instrumented with miniature pressure transducers that measured the aerodynamic response during the interaction. The results suggest that the rotor blade vortex interaction is similar in form to that measured at much higher spatial resolution on a fixed, non-rotating blade. The combination of the two datasets, therefore, provides a valuable resource for the development and validation of predictive schemes.

Novel method for calculating two-dimensional blade vortex interaction

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 909-912
Author(s):  
Ronald J. Epstein ◽  
John A. Rule ◽  
Donald B. Bliss
Keyword(s):  
Two Dimensional ◽  
Vortex Interaction ◽  
Blade Vortex Interaction ◽  
Novel Method

Development and Validation of Spectrophotometric and Liquid Chromatographic Methods for Estimation of Tigecycline in Injections

2020 ◽  
Vol 13 (5) ◽  
pp. 5148-5154
Author(s):  
Sagar Suman Panda ◽  
Ravi Kumar B.V.V.
Keyword(s):  
Area Under The Curve ◽  
Reversed Phase ◽  
Equal Concentration ◽  
Pharmaceutical Dosage Form ◽  
Liquid Chromatographic Method ◽  
Array Detection ◽  
The Difference ◽  
The One ◽  
Development And Validation ◽  
Liquid Chromatographic

Three new analytical methods were optimized and validated for the estimation of tigecycline (TGN) in its injection formulation. A difference UV spectroscopic, an area under the curve (AUC), and an ultrafast liquid chromatographic (UFLC) method were optimized for this purpose. The difference spectrophotometric method relied on the measurement of amplitude when equal concentration solutions of TGN in HCl are scanned against TGN in NaOH as reference. The measurements were done at 340 nm (maxima) and 410nm (minima). Further, the AUC under both the maxima and minima were measured at 335-345nm and 405-415nm, respectively. The liquid chromatographic method utilized a reversed-phase column (150mm×4.6mm, 5µm) with a mobile phase of methanol: 0.01M KH2PO4 buffer pH 3.5 (using orthophosphoric acid) in the ratio 80:20 %, v/v. The flow rate was 1.0ml/min, and diode array detection was done at 349nm. TGN eluted at 1.656min. All the methods were validated for linearity, precision, accuracy, stability, and robustness. The developed methods produced validation results within the satisfactory limits of ICH guidance. Further, these methods were applied to estimate the amount of TGN present in commercial lyophilized injection formulations, and the results were compared using the One-Way ANOVA test. Overall, the methods are rapid, simple, and reliable for routine quality control of TGN in the bulk and pharmaceutical dosage form. 

Blade-vortex interaction experiments - Velocity and vorticity fields

1990 ◽  
Author(s):  
MICHAEL WILDER ◽  
MATTHEW PESCE ◽  
DEMETRI TELIONIS ◽  
DAVIDR. POLING
Keyword(s):  
Vortex Interaction ◽  
Blade Vortex Interaction
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