3 edition of A parametric study of harmonic rotor hub loads found in the catalog.
A parametric study of harmonic rotor hub loads
by National Aeronautics and Space Administration, Scientific and Technical Information Program, National Technical Information Service, distributor] in [Washington, DC], [Springfield, Va
Written in English
|Series||NASA contractor report -- 4558., NASA contractor report -- NASA CR-4558.|
|Contributions||United States. National Aeronautics and Space Administration. Scientific and Technical Information Program.|
|The Physical Object|
plane hub loads and moments can not be significantly influenced by the rotor-damper configuration considered. A maximum load reduction of 72 % on the lateral hub load. Higher Harmonic Control Model .. Higher Harmonic Control Algorithms .. Actuator Power Required for HHC Systems .. 3 RESULTS AND DISCUSSION Correlation Study and HHC Effectiveness .. Correlation Study.
Correctly phased, this flap motion can be used for the active suppression of vibratory hub loads. First, the University of Maryland Advanced Rotorcraft Code was used to conduct a parametric study to determine the optimal flap sizing and location as well as Cited by: and 5/rev harmonic components. This study recommended that the potential effects of the drive train dynamics and in-plane hub motion be further investigated. The present paper investigates the UHA rotor structural loads from the ﬂight and wind tunnel tests to better under-stand the differences in chord bending moments observed inCited by: 1.
It was found that active camber morphing using superimposed once-per-revolution (1P) and 2P control inputs was able to simultaneously reduce rotor power by % and overall vibratory hub loads . turbine tower. The increase in diameter also makes the rotor and blade mass related requirements more severe. Not only do the blade root and the rotor hub need to sustain the static loads (the 62m world-largest blade weighs ~18T), but the nacelle structure, tower and foundations also need to sustain the whole machine dynamics.
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This report presents a parametric study of vibratory rotor hub loads in a nonrotating system. The study is based on a CAMRAD/JA model constructed for the "growth" version of the U.S.
Army's UHA Black Hawk helicopter (GBH). The GBH is a Math-scaled wind tunnel rotor model with high blade twist (°). The theoretical hub load. Get this from a library.
A parametric study of harmonic rotor hub loads. [Chengjian He; United States. National Aeronautics and Space Administration. Scientific. A parametric study of harmonic rotor hub loads [microform] / Chengjian He National Aeronautics and Space Administration, Scientific and Technical Information Program ; National Technical Information Service, distributor] [Washington, DC]: [Springfield, Va Australian/Harvard Citation.
He, Chengjian. & United States. A parametric study of vibratory rotor hub loads in a nonrotating system is presented. The study is based on a CAMRAD/JA model constructed for the GBH (Growth Version of Blackhawk Helicopter) Mach-scaled wind tunnel rotor model with high blade twist ( deg).Author: Chengjian He.
Predicted vibratory hub loads are correlated with experimental data obtained from a scaled model rotor. Results of a parametric study on a hingeless rotor show that blade flap, lag and torsion vibration characteristics, offset of blade center of mass from elastic axis, offset of elastic axis from quarter-chord axis, and blade thrust greatly affect the higher harmonic control Author: Inderjit Chopra and Khanh Nguyen.
A study of measured parametric effects of rotor loading on blade airloads, blade response, and hub forces on a high speed compound helicopter E. BENO 5th Annual Meeting and Technical Display August Cited by: Researchers study on passive and active methods to eliminate negative effects of aerodynamic loads.
Nowadays, active methods such as Higher Harmonic Control (HHC), Individual Blade Control (IBC), Active Control of Structural Response (ACSR), Active Twist Blade (ATB), and Active Trailing-edge Flap (ATF) gain importance to vibration and noise Author: Mürüvvet Sinem Sicim, Dinçer Demirci, Metin Orhan Kaya.
hub loads. First, the University of Maryland Advanced Rotorcraft Code was used to conduct a parametric study to determine the optimal ﬂap sizing and location as well as the required deﬂection by: Analysis of the UHA Rotor Loads Using Wind Tunnel Data predicted for both the parametric sweep conditions.
expensive rotor hub components. The harmonic content of loads in the rotating. For the rotor system analyzed here, these fixed-frame, vibratory hub loads are dominated by a four-per-revolution (4P) behavior due to having four-bladed rotors.
Fig. 11 shows the 4P magnitudes of all six components of loads (three forces and three moments) as functions of airspeed for all four values of lift offset.
For calculating the response and loads on the rotor, the complete aeroelastic equation was solved in modal space. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
A parametric study of harmonic rotor hub loads. NASA Contractor Reportby: 3. named Harmonic Balance Method for this study. Chouskey studied the influences of internal rotor material damping and the fluid film forces (generated as a result of hydrodynamic action in journal bearings) on the modal behavior of a flexible rotor-shaft system.
It File Size: KB. For estimation of helicopter vibrations one needs to calculate either the harmonics of the blade root or hub loads. For an N b bladed rotor, the loads transmitted to hub as primary source of vibration are the N b ± 1 per rev in-plane blade root shear forces (radial and drag), N b per rev vertical root shear force, N b ± 1 per rev torsional Cited by: 6.
The potential of an active camber mor-phing concept to reduce non-rotating vibratory hub loads and rotor power using active control was investigated. of a parametric study. Vibratory hub loads predicted by a comprehensive aeroelastic analysis are compared with wind tunnel test data.
The analysis is based on a finite element method in space and time. Rotor loads. An embedded radial absorber is investigated to control helicopter rotor hub vibration and blade loads.
The absorber is modeled as a discrete mass moving in. Meeting Paper Home; For Authors ; Structures, Structural Dynamics, and Materials and Co-located Conferences Home. well documented. This paper presents an acoustics parametric sensitivity analysis of the effect of varying rotor aerodynamic pitch hub trim moments on BVI noise radiated by an S helicopter main rotor.
Results show that changing the hub pitching moment for an isolated rotor, trimmed in nominal 80 knot, 6 and 12 deg descent, flight. Based on Dr. Muszy(n´)ska's extensive work at Bently Rotor Dynamics Research Corporation, world renowned for innovative and groundbreaking experiments in the field, this book provides realistic models, step-by-step experimental methods, and the principles of vibration monitoring and practical malfunction diagnostics of rotating machinery.
Comparison study of different rotor systems indicates that a soft-inplane hingeless rotor requires less actuator power at high speeds (above knots) than an articulated rotor, and a stiff-inplane hingeless rotor generally requires more actuator power than an articulated or a soft-inplane hingeless rotor.
Parametric studies for a hingeless Author: Khanh Q. Nguyen. This paper presents an acoustics parametric study of the effect of varying lateral and longitudinal rotor trim flapping x which harmonic rotor noise is generatedHub roll moment, The AW rotor (Ref.
10) employs a gimballed hub. Its main characteristics are summarized in Table 1. Table 1. AW Rotor Characteristics.Aerodynamic forces were calculated with a free-vortex wake model together with lifting line theory for the blade aerodynamics.
The open-loop investigation comprised of a parametric study of relevant control parameters that govern the active camber deflection cyclic actuation profile and their effects on rotor performance and hub : Sumeet Kumar, Dominik Komp, Manfred Hajek, Jürgen Rauleder.In the current study, the full-scale wind tunnel data for the UHA rotor2 will be used to compare measured rotor airloads, structural loads and performance indicators with predictions.
In this study, two parametric sweeps will be investigated. The first parametric sweep study consists of a range of advance ratios, µ = toat.