Dissertations / Theses: 'Rotors (Helicopters)'

1

Atilgan, Ali Rana. "Towards a unified analysis methodology for composite rotor blades." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/15403.

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2

Taylor, Dana J. "A method for the efficient calculation of elastic rotor blade dynamic response in forward flight." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/12396.

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3

Ozturk, Dogan. "Development of a Myklestad's rotor blade dynamic analysis code for application to JANRAD." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FOzturk.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 2002.
Thesis advisor(s): E. Roberts Wood, Mark A. Couch. Includes bibliographical references (p. 213-214). Also available online.

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4

Van, Riper Steven G. "Investigation of increased forward flight velocities of helicopters using second harmonic control and reverse velocity rotor concept." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FVanRiper.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, December 2003.
Thesis advisor(s): E. Roberts Wood, Raymond Shreeve. Includes bibliographical references (p. 145-146). Also available online.

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5

Akin, Hakki E. "A computer code for rapid calculation of bending frequencies of rotor blades." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FAkin.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, June 2002.
Thesis advisor(s): E. Roberts Wood, Mark A. Couch. Includes bibliographical references (p. 195-196). Also available online.

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6

Collins, Kyle Brian. "A multi-fidelity framework for physics based rotor blade simulation and optimization." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26481.

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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.
Committee Co-Chair: Dr. Dimitri Mavris; Committee Co-Chair: Dr. Lakshmi N. Sankar; Committee Member: Dr. Daniel P. Schrage; Committee Member: Dr. Kenneth S. Brentner; Committee Member: Dr. Mark Costello. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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7

Sturisky, Selwyn H. "A linear system identification and validaton of an AH-64 apache aeroelastic simulation model." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/13402.

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8

Teare, David Alan. "Modeling and system identification for rotorcraft." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/17088.

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9

Tatossian, Charles A. "Aerodynamic shape optimization via control theory of helicopter rotor blades using a non-linear frequency domain approach." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112586.

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This study presents a discrete adjoint-based aerodynamic optimization algorithm for helicopter rotor blades in hover and forward flight using a Non-Linear Frequency Domain approach. The goal is to introduce a Mach number variation into the Non-Linear Frequency Domain (NLFD) method and implement a novel approach to present a time-varying cost function through a multi-objective adjoint boundary condition. The research presents the complete formulation of the time dependent optimal design problem. The approach is firstly demonstrated for the redesign of a NACA 0007 and a NACA 23012 helicopter rotor blade section in forward flight. A three-dimensional inviscid Aerodynamic Shape Optimization (ASO) algorithm is then employed to validate and redesign the Caradonna and Tung experimental blade. The results in determining the optimum aerodynamic configurations require an objective function which minimizes the inviscid torque coefficient and maintains the desired thrust level at transonic conditions.

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10

Su, Ay. "Application of a state-space wake model to elastic blade flapping in hover." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/11965.

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11

de, Andrade Donizeti. "Application of finite-state inflow to flap-lag-torsion damping in hover." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/12412.

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12

Berry, John D. "A method of computing the aerodynamic interactions of a rotor-fuselage configuration in forward flight." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12936.

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13

Wang, Yi-Ren. "The effect of wake dynamics on rotor eigenvalues in forward flight." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13031.

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14

Stettner, Martin. "Application of a state-space wake model to a servo flap controlled rotor in hover." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/20202.

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15

Rauchenstein, Werner J. "A 3D Theodorsen-based rotor blade flutter model using normal modes." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FRauchenstein.pdf.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 2002.
Thesis advisor(s): E. Roberts Wood, Mark A. Couch. Includes bibliographical references (p. 55-56). Also available online.

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16

Fulton, Mark V. "Stability of elastically tailored rotor blades." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/12248.

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17

Prichard, Devon S. "Development of a full potential solver for rotor aerodynamics analysis." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12033.

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18

He, Chengjian. "Development and application of a generalized dynamic wake theory for lifting rotors." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12389.

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19

Bitzer, Michael. "Identification of an improved body aerodynamics model for the BO 105." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/13832.

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20

Xin, Hong. "Development and validation of a generalized ground effect model for lifting rotors." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/11880.

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21

O'Brien, David Michael Jr. "Analysis Of Computational Modeling Techniques For Complete Rotorcraft Configurations." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10535.

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Recent increases in computing power and memory have created renewed interest in alternative grid schemes such as unstructured grids, which facilitate rapid grid generation by relaxing restrictions on grid structure. Three rotor models have been incorporated into a popular fixed-wing unstructured computational fluid dynamics (CFD) solver to increase its capability and facilitate availability to the rotorcraft community. The benefit of unstructured grid methods is demonstrated through rapid generation of high fidelity configuration models. The simplest rotor model is the steady state actuator disk approximation. By transforming the unsteady rotor problem into a steady state one, the actuator disk can provide rapid predictions of performance parameters such as lift and drag. The actuator blade and overset blade models provide a depiction of the unsteady rotor wake, but incur a larger computational cost than the actuator disk. The actuator blade model is convenient when the unsteady aerodynamic behavior needs to be investigated, but the computational cost of the overset approach is too large. The overset or chimera method allows the blades loads to be computed from first-principles and therefore provides the most accurate prediction of the rotor wake for the models investigated. The physics of the flow fields of these models for rotor/fuselage interaction are explored, along with efficiencies and limitations of each methodology.

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22

Brand, Albert G. "An experimental investigation of the interaction between a model rotor and airframe in forward flight." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12433.

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23

Thompson, Thomas L. "Velocity measurements near the blade tip and in the tip vortex core of a hovering model rotor." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/13003.

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24

Sarvat, Mushtaq Ahmad B. "Modelling and control of a twin rotor MIMO system." Thesis, University of Sheffield, 2001. http://etheses.whiterose.ac.uk/14820/.

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In this research, a laboratory platform which has 2 degrees of freedom (DOF), the Twin Rotor MIMO System (TRMS), is investigated. Although, the TRMS does not fly, it has a striking similarity with a helicopter, such as system nonlinearities and cross-coupled modes. Therefore, the TRMS can be perceived as an unconventional and complex "air vehicle" that poses formidable challenges in modelling, control design and analysis and implementation. These issues are the subject of this work. The linear models for 1 and 2 DOFs are obtained via system identification techniques. Such a black-box modelling approach yields input-output models with neither a priori defined model structure nor specific parameter settings reflecting any physical attributes. Further, a nonlinear model using Radial Basis Function networks is obtained. Such a high fidelity nonlinear model is often required for nonlinear system simulation studies and is commonly employed in the aerospace industry. Modelling exercises were conducted that included rigid as well as flexible modes of the system. The approach presented here is shown to be suitable for modelling complex new generation air vehicles. Modelling of the TRMS revealed the presence of resonant system modes which are responsible for inducing unwanted vibrations. In this research, open-loop, closed-loop and combined open and closed-loop control strategies are investigated to address this problem. Initially, open-loop control techniques based on "input shaping control" are employed. Digital filters are then developed to shape the command signals such that the resonance modes are not overly excited. The effectiveness of this concept is then demonstrated on the TRMS rig for both 1 and 2 DOF motion, with a significant reduction in vibration. The linear model for the 1 DOF (SISO) TRMS was found to have the non-minimum phase characteristics and have 4 states with only pitch angle output. This behaviour imposes certain limitations on the type of control topologies one can ado·pt. The LQG approach, which has an elegant structure with an embedded Kalman filter to estimate the unmeasured states, is adopted in this study. The identified linear model is employed in the design of a feedback LQG compensator for the TRMS with 1 DOF. This is shown to have good tracking capability but requires. high control effort and has inadequate authority over residual vibration of the system. These problems are resolved by further augmenting the system with a command path prefilter. The combined feedforward and feedback compensator satisfies the performance objectives and obeys the constraint on the actuator. Finally, 1 DOF controller is implemented on the laboratory platform.

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25

Yoo, Kyung M. "Unsteady vortex lattice aerodynamics for rotor aeroelasticity in hover and in forward flight." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/11961.

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26

Kaladi, Vasudevan M. "Unsteady compressible lifting surface analysis for rotary wings using velocity potential modes." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12524.

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27

Gündüz, Mustafa Emre. "Software integration for automated stability analysis and design optimization of a bearingless rotor blade." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33916.

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The concept of applying several disciplines to the design and optimization processes may not be new, but it does not currently seem to be widely accepted in industry. The reason for this might be the lack of well-known tools for realizing a complete multidisciplinary design and analysis of a product. This study aims to propose a method that enables engineers in some design disciplines to perform a fairly detailed analysis and optimization of a design using commercially available software as well as codes developed at Georgia Tech. The ultimate goal is when the system is set up properly, the CAD model of the design, including all subsystems, will be automatically updated as soon as a new part or assembly is added to the design; or it will be updated when an analysis and/or an optimization is performed and the geometry needs to be modified. Such a design process takes dramatically less time to complete; therefore, it should reduce development time and costs. The optimization method is demonstrated on an existing helicopter rotor originally designed in the 1960's. The rotor is already an effective design with novel features. However, application of the optimization principles together with high-speed computing resulted in an even better design. The objective function to be minimized is related to the vibrations of the rotor system under gusty wind conditions. The design parameters are all continuous variables. Optimization is performed in a number of steps. First, the most crucial design variables of the objective function are identified. With these variables, Latin Hypercube Sampling method is used to probe the design space of several local minima and maxima. After analysis of numerous samples, an optimum configuration of the design that is more stable than that of the initial design is reached. The process requires several software tools: CATIA as the CAD tool, ANSYS as the FEA tool, VABS for obtaining the cross-sectional structural properties, and DYMORE for the frequency and dynamic analysis of the rotor. MATLAB codes are also employed to generate input files and read output files of DYMORE. All these tools are connected using ModelCenter.

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28

Usta, Ebru. "Application of a symmetric total variation diminishing scheme to aerodynamics of rotors." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13018.

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29

Schaefer, Carl George. "Enhanced energy maneuverability for attack helicopters using continuous, variable rotor speed control." Master's thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03302010-020156/.

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30

Yang, Zhong. "A hybrid flow analysis for rotors in forward flight." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/13016.

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31

Soykasap, Omer. "Aeroelastic optimization of a composite tilt rotor." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/11823.

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32

Zaki, Afifa Adel. "Using tightly-coupled CFD/CSD simulation for rotorcraft stability analysis." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43579.

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Dynamic stall deeply affects the response of helicopter rotor blades, making its modeling accuracy very important. Two commonly used dynamic stall models were implemented in a comprehensive code, validated, and contrasted to provide improved analysis accuracy and versatility. Next, computational fluid dynamics and computational structural dynamics loose coupling methodologies are reviewed, and a general tight coupling approach was implemented and tested. The tightly coupled computational fluid dynamics and computational structural dynamics methodology is then used to assess the stability characteristics of complex rotorcraft problems. An aeroelastic analysis of rotors must include an assessment of potential instabilities and the determination of damping ratios for all modes of interest. If the governing equations of motion of a system can be formulated as linear, ordinary differential equations with constant coefficients, classical stability evaluation methodologies based on the characteristic exponents of the system can rapidly and accurately provide the system's stability characteristics. For systems described by linear, ordinary differential equations with periodic coefficients, Floquet's theory is the preferred approach. While these methods provide excellent results for simplified linear models with a moderate number of degrees of freedom, they become quickly unwieldy as the number of degrees of freedom increases. Therefore, to accurately analyze rotorcraft aeroelastic periodic systems, a fully nonlinear, coupled simulation tool is used to determine the response of the system to perturbations about an equilibrium configuration and determine the presence of instabilities and damping ratios. The stability analysis is undertaken using an algorithm based on a Partial Floquet approach that has been successfully applied with computational structural dynamics tools on rotors and wind turbines. The stability analysis approach is computationally inexpensive and consists of post processing aeroelastic data, which can be used with any aeroelastic rotorcraft code or with experimental data.

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33

Kwon, Oh Joon. "A technique for the prediction of aerodynamics and aeroelasticity of rotor blades." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/12159.

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34

Chouchane, Mnaouar. "Application of a dynamic stall model to rotor trim and aeroelastic response." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12368.

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35

Liou, Shiuh-Guang. "Velocity measurements on a lifting rotor/airframe configuration in low speed forward flight." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/12479.

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36

Huang, Ming-Sheng. "Coupled elastic rotor/body vibrations with inplane degrees of freedom." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/12495.

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37

Smith, Marilyn Jones. "A fourth order Euler/Navier-Stokes prediction method for the aerodynamics and aeroelasticity of hovering rotor blades." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/13058.

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38

Stumpf, Walter Martin. "An integrated finite-state model for rotor deformation, nonlinear airloads, inflow and trim." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13341.

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39

Hashemi-kia, Mostafa. "Dynamic testing techniques and applications for an aeroelastic rotor test facility." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/13887.

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40

Scott, James Georg. "Establishment of a remotely piloted helicopter test flight program for higher harmonic control research." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA234978.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, June 1990.
Thesis Advisor(s): Wood, E. Roberts. Second Reader: Howard, Richard M. "June 1990." Description based on title screen as viewed on October 20, 2009. DTIC Identifier(s): Remotely Piloted Vehicles, Helicopter Rotors, Flight Control Systems, Harmonics, HHC (Higher Harmonic Control), Unmanned Air Vehicles, Vibration Control, Theses. Author(s) subject terms: HHC, RPH, UAV, RPV, Vibration, Controls, Torsional Constant, Freeplay. Includes bibliographical references (p. 62-63). Also available online.

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41

Tai, Jimmy C. M. "A multidisciplinary design approach to size stopped rotor/wing configurations using reaction drive and circulation control." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13460.

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42

Rajmohan, Nischint. "Application of hybrid methodology to rotors in steady and maneuvering flight." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34756.

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Helicopters are versatile flying machines that have capabilities that are unparalleled by fixed wing aircraft, such as operating in hover, performing vertical take-off and landing on unprepared sites. However, modern helicopters still suffer from high levels of noise and vibration caused by the physical phenomena occurring in the vicinity of the rotor blades. Therefore, improvement in rotorcraft design to reduce the noise and vibration levels requires understanding of the underlying physical phenomena, and accurate prediction capabilities of the resulting rotorcraft aeromechanics. The goal of this research is to study the aeromechanics of rotors in steady and maneuvering flight using hybrid Computational Fluid Dynamics (CFD) methodology. The hybrid CFD methodology uses the Navier-Stokes equations to solve the flow near the blade surface but the effect of the far wake is computed through the wake model. The hybrid CFD methodology is computationally efficient and its wake modeling approach is non-dissipative making it an attractive tool to study rotorcraft aeromechanics. Several enhancements were made to the CFD methodology and it was coupled to a Computational Structural Dynamics (CSD) methodology to perform a trimmed aeroelastic analysis of a rotor in forward flight. The coupling analyses, both loose and tight were used to identify the key physical phenomena that affect rotors in different steady flight regimes. The modeling enhancements improved the airloads predictions for a variety of flight conditions. It was found that the tightly coupled method did not impact the loads significantly for steady flight conditions compared to the loosely coupled method. The coupling methodology was extended to maneuvering flight analysis and the flight test control angles were employed to enable the maneuvering flight analysis. The fully coupled model provided the presence of three dynamic stall cycles on the rotor in maneuver. Analysis of maneuvering ﬂight requires knowledge of the pilot input control pitch settings, and the vehicle states. As the result, these computational tools cannot be used for analysis of loads in a maneuver that has not been duplicated in a real flight. This is a significant limitation if these tools are to be selected during the design phase of a helicopter where its handling qualities are evaluated in different trajectories. Therefore, a methodology was developed to couple the CFD/CSD simulation with an inverse flight mechanics simulation to perform the maneuver analysis without using the flight test control input. The methodology showed reasonable convergence in steady and maneuvering flight regimes and control angle predictions compared fairly well with test data. In the maneuvering flight regions, the convergence was slower due to relaxation techniques used for the numerical stability. Further, the enhancement of the rotor inflow computations in the inverse simulation through implementation of a Lagrangean wake model improved the convergence of the coupling methodology.

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43

Rye, David Charles. "The longitudinal stability of a tethered rotary-winged aircraft." Thesis, The University of Sydney, 1986. http://hdl.handle.net/2123/18484.

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A linearised mathematical representation of a tethered rctorcraft is developed in order to study the influence of various parameters on the machine’s longitudinal stability. The investigation is concerned principally with a vehicle having two side-by-side contrarotating rotors and a large tailplane. The first part of the thesis consists of a detailed development of the trim equations, and of linearised equations of longitudinal motion which are written in Earth-fixed axes. Aerodynamic derivatives are used to account for the perturbations to rotor and tailplane aerodynamic forces. Dcwnwash lag derivatives are developed using a hcrseshcevortex- plus-wake representation of the flew field of a rotor in forward flight. Because the analysis concentrates on the vehicle's dynamics, a simple quasi-static representation of the single tethering cable is adopted. This approach is adequate provided that the cable mass is a small fraction of the vehicle's mass. When the tether is straight and may be considered inelastic, the Routh-Hurwitz criteria predict that the machine can be made inherently stable in hcver by increasing the thrust tc weight ratio, provided that the cable length dees not exceed a certain small value. The tether must also be attached above the machine's centre of mass tc prevent an aperiodic "pendular" divergence. The same stability criteria show that the machine will be unstable in hcver when the tethering cable is long. When the tether is curved or elastic, simple analytic stability criteria cannot be obtained. Instead, in the second part of the thesis, the influence of various parameters on the vehicle's behaviour is examined by numerically solving particular characteristic equations. The numerical studies show that many vehicle ccnfigurations can be stable in wind, but most are unstable in hcver. The cable attachment point height remains a dominant parameter for hover flight, and in wind. Instability in hover often takes the form of a coupled pitch-translation oscillation similar to that observed in a conventional helicopter. Attaching the tether below the centre of mass can stabilise this oscillation, but results in an aperiodic divergent "pendular" mode. In wind, a tailplane of suitable size will impart asymptotic stability to the system. In strong winds a long tethering cable will be highly curved. The vehicle’s dynamic behaviour is then substantially unrelated to the cable profile. The natural modes shew little dependence on the machine’s geometry, and are strongly influenced by the horizontal tail surface.

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44

Russell, Gregory T. "Development of an analytical model for pitch link loads of bearingless main rotors." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2007. http://wwwlib.umi.com/cr/syr/main.

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45

Steyn, J. (Johannes). "Design, manufacture and test of a bearingless rotor hub for the 24% scale model of the Rooivalk attack helicopter." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51676.

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Thesis (MEng) -- Stellenbosch University, 2000.
Some digitised pages may appear illegible due to the condition of the original hard copy.
ENGLISH ABSTRACT: This document contains the work done on the bearingless rotor hub for the 24% scale model of the Rooivalk Attack Helicopter situated at the CSIR in Pretoria. This work forms part of the MSc Ing degree of Johannes Steyn. This work was deemed necessary because of a movement away from the fully articulated rotor to one of hingeless and more recently bearingless rotors. The main emphasis of this thesis is to be a technology demonstrator more than the design of a fully working bearingless rotor hub. With this in mind the final design in this report is not an optimal one, but the procedures and methodology in getting to a design are laid out in this document. To verify the design, tests were identified and created. The procedures for these tests are also included in this document. For the fatigue test a test bench had to be designed and built. This document also includes the design of this test bench
AFRIKAANSE OPSOMMING: Die dokument lewer verslag van die aktiwiteite vir die ontwerp van ‘n laerlose rotor van die 24% skaal model van die Rooivalk Helikopter, gelee by die WNNR in Pretoria. Die werk gedoen vorm deel van die MSc Ing graad van Johannes Steyn. Die werk is nodig geag omdat daar ‘n tendens is om weg te beweeg van die volledig geartikuleerde rotor na die van ‘n skanierlose en meer huidig ‘n laerlose rotor. Die hoof klem van die tesis is om as tegnologie demonstrator op te tree, eerder as die daarstel van ‘n werkende laerlose rotor. Na aanleiding van bogenoemde stelling kan die finale ontwerp nie as optimaal beskou word nie. Die prosedures en metodiek wat gevolg is om die ontwerp te kry word uitgele in die dokument. Om die ontwerp te verifieer is toetse gei'dentifiseer. Die prosedures vir elk van die toetse word ook in die dokument ingesluit. Vir die uitputtingstoetse moes ‘n spesiale toetsbank ontwerp en gebou word. Die ontwerp van hierdie toetsbank is ook in die dokument.

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46

Eckert, Bernd. "Analytical and a numerical ground resonance analysis of a conventionally articulated main rotor helicopter." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/385.

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47

Kim, Young K. "A numerical solution of implicit nonlinear equations of motion for rotor blades." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/12047.

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48

Mavris, Dimitri N. "An analytical method for the prediction of unsteady rotor/airframe interactions in forward flight." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/12109.

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49

Mittal, Manoj. "Modeling and control of a twin-lift helicopter system." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/12174.

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50

Wong, Oliver D. "Formation and evolution of tip vortices of an isolated rotor in forward flight." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12377.

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Dissertations / Theses on the topic 'Rotors (Helicopters)'

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