Bibliographies thématiques / Rotorcraft aeromechanics

Littérature scientifique sur le sujet « Rotorcraft aeromechanics »

Auteur : Grafiati

Publié le 14 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Sommaire

Articles de revues
Thèses
Livres
Chapitres de livres
Actes de conférences
Rapports d'organisations

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Rotorcraft aeromechanics ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Rotorcraft aeromechanics"

Chopra, Inderjit. « Rotorcraft Aeromechanics ». Journal of the American Helicopter Society 58, n^o 3 (1 juillet 2013) : 1. http://dx.doi.org/10.4050/jahs.58.037001.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Leishman, J. Gordon. « Rotorcraft Aeromechanics : Getting through the Dip ». Journal of the American Helicopter Society 55, n^o 1 (1 janvier 2010) : 11001–1100124. http://dx.doi.org/10.4050/jahs.55.011001.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rutkowski, Michael J., Gene C. Ruzicka, Robert A. Ormiston, Hossein Saberi et Yoon Jung. « Comprehensive Aeromechanics Analysis of Complex Rotorcraft Using 2GCHAS ». Journal of the American Helicopter Society 40, n^o 4 (1 octobre 1995) : 3–17. http://dx.doi.org/10.4050/jahs.40.3.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lovera, Marco, Patrizio Colaneri et Roberto Celi. « On the Role of Zeros in Rotorcraft Aeromechanics ». Journal of the American Helicopter Society 49, n^o 3 (1 juillet 2004) : 318–27. http://dx.doi.org/10.4050/jahs.49.318.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Masarati, Pierangelo, Giuseppe Quaranta et Michael Jump. « Experimental and numerical helicopter pilot characterization for aeroelastic rotorcraft–pilot coupling analysis ». Proceedings of the Institution of Mechanical Engineers, Part G : Journal of Aerospace Engineering 227, n^o 1 (16 décembre 2011) : 125–41. http://dx.doi.org/10.1177/0954410011427662.

Texte intégral

Résumé :

Pilot–vehicle interaction represents a critical aspect of aircraft design. Very low-frequency, voluntary although unintentional interaction has been extensively investigated in fixed and rotary wing aeromechanics. Higher frequency, involuntary and thus passive interaction received similar attention in fixed wing aeromechanics, but not as much for rotary wing. The results of an experimental campaign for the characterization of the passive behaviour of rotorcraft pilots' biomechanics are presented. A flight simulator has been used to excite human subjects. The accelerations of their limbs and the motion induced by the vibrations of the limbs in the control inceptors have been recorded. The vertical, longitudinal and lateral directions have been independently excited, while measuring the motion of the arm directly involved in the control inceptor mostly affected by motion in each direction, namely the left and the right arms for the collective and the cyclic sticks, respectively. The frequency domain response has been evaluated; resulting noteworthy behaviour is discussed, addressing its relevance in modelling the passive behaviour of pilots within the bioaeroservoelastic rotorcraft analysis. The measurements of human body impedance, under realistic cockpit motion, are used to identify the direct transfer functions between the motion of the seat and the controls inadvertently fed back into the rotorcraft.

Styles APA, Harvard, Vancouver, ISO, etc.

Johnson, Wayne. « Milestones in Rotorcraft Aeromechanics Alexander A. Nikolsky Honorary Lecture ». Journal of the American Helicopter Society 56, n^o 3 (1 juillet 2011) : 1–24. http://dx.doi.org/10.4050/jahs.56.031001.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Keßler, Manuel. « Rotorcraft Aeromechanics Simulation - When applied mathematics hits real engineering ». PAMM 17, n^o 1 (décembre 2017) : 133–36. http://dx.doi.org/10.1002/pamm.201710038.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Yeo, Hyeonsoo, et Robert A. Ormiston. « UH-60A Airloads Workshop—Setting the Stage for the Rotorcraft CFD/CSD Revolution, Part II : Ongoing Progress, Impact, and Lessons Learned ». Journal of the American Helicopter Society 67, n^o 2 (1 avril 2022) : 1–16. http://dx.doi.org/10.4050/jahs.67.022011.

Texte intégral

Résumé :

The UH-60A Airloads Workshop was a unique collaboration of aeromechanics experts from the U.S. Government, industry, and academia to address technical issues that hindered accurate rotor loads predictions. The Airloads Workshop leveraged the NASA/Army UH-60A Airloads flight test and NFAC wind tunnel test data. It functioned continuously for 17 years, from 2001 to 2018, and brought about one of the most important advancements in rotorcraft aeromechanics prediction capabilities by successfully demonstrating high-fidelity coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) analyses for both steady and maneuvering flight. The article is divided into two parts. Part I surveys the background of rotorcraft CFD/CSD development difficulties, the origins of the Airloads Workshop, and the rapid success achieved during the first phase that consisted of eight Workshops. Part II describes ongoing development during the subsequent two phases of the Airloads Workshop, the Ninth through the 13th, and the 14th through the 31st Workshops. Part II outlines development of CFD/CSD methods to predict rotor airloads for the challenging maneuvering flight condition and also describes the impact of the newly developed CFD/CSD methods and how they were transferred to the larger technical community, opening the door for practical application of CFD methods for designing future advanced rotorcraft. Part II concludes with a discussion of why the Airloads Workshop succeeded and lessons learned from the collaborative effort.

Styles APA, Harvard, Vancouver, ISO, etc.

Yeo, Hyeonsoo, et Robert A. Ormiston. « UH-60A Airloads Workshop—Setting the Stage for the Rotorcraft CFD/CSD Revolution, Part I : Background and Initial Success ». Journal of the American Helicopter Society 67, n^o 2 (1 avril 2022) : 1–17. http://dx.doi.org/10.4050/jahs.67.022010.

Texte intégral

Résumé :

The UH-60A Airloads Workshop was a unique collaboration of aeromechanics experts from the U.S. Government, industry, and academia to address technical issues that hindered accurate rotor loads predictions. The Airloads Workshop leveraged the NASA/Army UH-60A Airloads flight test and NFAC wind tunnel test data. It functioned continuously for 17 years, from 2001 to 2018, and brought about one of the most important advancements in rotorcraft aeromechanics prediction capabilities by successfully demonstrating high-fidelity coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) analyses for both steady and maneuvering flight. The article is divided into two parts. Part I surveys the background of rotorcraft CFD/CSD development difficulties, the origins of the Airloads Workshop, and the rapid success achieved during the first phase that consisted of eight Workshops. Part II describes ongoing development during the subsequent two phases of the Airloads Workshop, the Ninth through the 13th, and the 14th through the 31st Workshops; the impact of the Airloads Workshop; and the lessons learned. Part I surveys the technical activities that led to a breakthrough for CFD/CSD coupling to successfully predict rotor blade airloads in trimmed steady-level flight conditions. This success illustrated the importance of collaboration among key experts with diverse backgrounds focused on a common objective to advance rotorcraft prediction methods.

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "Rotorcraft aeromechanics"

Liu, Haiying. « Interfacing comprehensive rotorcraft analysis with advanced aeromechanics and vortex wake models ». Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22534.

Texte intégral

Résumé :

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Bauchau, Olivier; Committee Member: Armanios, Erian; Committee Member: Hodges, Dewey; Committee Member: Ruzzene, Massimo; Committee Member: Stallybrass, Michael.

Styles APA, Harvard, Vancouver, ISO, etc.

BARRA, FEDERICO. « Mathematical modelling of tilt-rotor aircraft configurations. A comprehensive model for flight control system development and real-time piloted simulation ». Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2971116.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Marpu, Ritu Priyanka. « Physics based prediction of aeromechanical loads for the UH-60A rotor ». Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47661.

Texte intégral

Résumé :

Helicopters in forward flight experience complex aerodynamic phenomena to various degrees. In low speed level flight, the vortex wake remains close to the rotor disk and interacts with the rotor blades to give rise to blade vortex interaction phenomena. In high speed flight, compressibility effects dominate leading to the formation of shocks. If the required thrust is high, the combination of high collective pitch and cyclic pitch variations give rise to three-dimensional dynamic stall phenomena. Maneuvers further exacerbate the unsteady airloads and affect rotor and hub design. The strength and durability of the rotor blades and hub components is dependent on accurate estimates of peak-to-peak structural loads. Accurate knowledge of control loads is important for sizing the expensive swash-plate components and assuring long fatigue life. Over the last two decades, computational tools have been developed for modeling rotorcraft aeromechanics. In spite of this progress, loads prediction in unsteady maneuvers which is critical for peak design loads continues to be a challenging task. The primary goal of this research effort is to investigate important physical phenomena that cause severe loads on the rotor in steady flight and in extreme maneuvers. The present work utilizes a hybrid Navier-Stokes/free-wake CFD methodology coupled to a finite element based multi-body dynamics analysis to systematically study steady level and maneuvering flight conditions. Computational results are presented for the UH-60A rotor for a parametric sweep of speed and thrust conditions and correlated with test data at the NFAC Wind Tunnel. Good agreement with test data has been achieved using the current methodology for trim settings and integrated hub loads, torque, and power. Two severe diving turn maneuvers for the UH-60A recorded in the NASA/Army Airloads Flight Tests Database have also been investigated. These maneuvers are characterized by high load factors and high speed flight. The helicopter experiences significant vibration during these maneuvers. Mean and peak-to-peak structural loads and extensive stall phenomena including an advancing side stall phenomena have been captured by the present analyses.

Styles APA, Harvard, Vancouver, ISO, etc.

Agarwal, Sandeep. « Aeromechanical Stability Augmentation Using Semi-Active Friction-Based Lead-Lag Damper ». Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7547.

Texte intégral

Résumé :

Lead-lag dampers are present in most rotors to provide the required level of damping in all flight conditions. These dampers are a critical component of the rotor system, but they also represent a major source of maintenance cost. In present rotor systems, both hydraulic and elastomeric lead-lag dampers have been used. Hydraulic dampers are complex mechanical components that require hydraulic fluids and have high associated maintenance costs. Elastomeric dampers are conceptually simpler and provide a ``dry" rotor, but are rather costly. Furthermore, their damping characteristics can degrade with time without showing external signs of failure. Hence, the dampers must be replaced on a regular basis. A semi-active friction based lead-lag damper is proposed as a replacement for hydraulic and elastomeric dampers. Damping is provided by optimized energy dissipation due to frictional forces in semi-active joints. An actuator in the joint modulates the normal force that controls energy dissipation at the frictional interfaces, resulting in large hysteretic loops. Various selective damping strategies are developed and tested for a simple system containing two different frequency modes in its response, one of which needs to be damped out. The system reflects the situation encountered in rotor response where 1P excitation is present along with the potentially unstable regressive lag motion. Simulation of the system response is obtained to compare their effectiveness. Next, a control law governing the actuation in the lag damper is designed to generate the desired level of damping for performing adaptive selective damping of individual blade lag motion. Further, conceptual design of a piezoelectric friction based lag damper for a full-scale rotor is presented and various factors affecting size, design and maintenance cost, damping capacity, and power requirements of the damper are discussed. The selective semi-active damping strategy is then studied in the context of classical ground resonance problem. In view of the inherent nonlinearity in the system due to friction phenomena, multiblade transformation from rotating frame to nonrotating frame is not useful. Stability analysis of the system is performed in the rotating frame to gain an understanding of the dynamic characteristics of rotor system with attached semi-active friction based lag dampers. This investigation is extended to the ground resonance stability analysis of a comprehensive UH-60 model within the framework of finite element based multibody dynamics formulations. Simulations are conducted to study the performance of several integrated lag dampers ranging from passive to semi-active ones with varying levels of selectivity. Stability analysis is performed for a nominal range of rotor speeds using Prony's method.

Styles APA, Harvard, Vancouver, ISO, etc.

Livres sur le sujet "Rotorcraft aeromechanics"

H, Hodges Dewey, Ames Research Center et United States. Army Aviation Research and Technology Activity., dir. General rotorcraft aeromechanical stability program (GRASP) theory manual. Moffett Field, Calif : National Aeronautics and Space Administration, Ames Research Center, 1990.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

L, Kunz Donald, et Ames Research Center, dir. General rotorcraft aeromechanical stability program (GRASP) : Version 1.03, user's manual. Moffett Field, Calif : National Aeronautics and Space Administration, Ames Research Center, 1988.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Johnson, Wayne. Rotorcraft Aeromechanics. Cambridge University Press, 2013.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Johnson, Wayne. Rotorcraft Aeromechanics. Cambridge University Press, 2013.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rotorcraft Aeromechanics. Cambridge University Press, 2013.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Johnson, Wayne. Rotorcraft Aeromechanics. Cambridge University Press, 2013.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

National Aeronautics and Space Administration (NASA) Staff. General Rotorcraft Aeromechanical Stability Program : Theory Manual. Independently Published, 2018.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Chapitres de livres sur le sujet "Rotorcraft aeromechanics"

Appleton, Wesley. « Tiltrotor Aeromechanics ». Dans Lecture Notes in Rotorcraft Engineering, 115–39. Cham : Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-12437-2_5.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Rotorcraft aeromechanics"

Yeo, Hyeonsoo, et Robert Ormiston. « UH-60A Airloads Workshop - Setting the Stage for the Rotorcraft CFD/CSD Revolution ». Dans Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16775.

Texte intégral

Résumé :

The UH-60A Airloads Workshop was a unique collaboration of aeromechanics experts from U.S. Government, industry, and academia to address technical issues that hindered accurate rotor loads predictions. The Airloads Workshop leveraged the NASA/Army UH-60A Airloads flight test and NFAC wind tunnel test data. It functioned continuously for 17 years, from 2001 to 2018, and broughtabout one of the most important advancementsin rotorcraft aeromechanics prediction capabilities by successfully demonstrating high-fidelity coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) analyses for both steady and maneuvering flight. This paper describes the origins of the Airloads Workshop, how it worked, and why it succeeded. Most importantly a collaboration of key experts with diverse backgrounds focused on a common objective is perhaps the most effective approach for challenging problems. The paper surveys the technical activities that led to the successful CFD/CSD coupling for predicting airloads in challenging steady-level and maneuvering flight conditions that opened the door for practical application of CFD methods for designing future advanced rotorcraft. Lessons learned from the collaborative efforts to advance rotorcraft science and technology will continue to play a significant role for future rotorcraft research, design, and development activities.

Styles APA, Harvard, Vancouver, ISO, etc.

Abate, Giuseppe, Matteo Daniele, Neda Taymourtash et Giuseppe Quaranta. « Verification, Validation and Calibration Under Uncertainty for a Scaled Experimental Rotor Model ». Dans Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17583.

Texte intégral

Résumé :

Virtual Engineering (VE) in rotorcraft design is a well-established approach to support decision-making throughout the rotorcraft's life-cycle (Ref. 1). The effectiveness of structural design, analysis and CAD software, CFD solvers and rotor aeromechanics codes is crucial throughout rotorcraft life-cycle, from preliminary design phase development to certification process (Ref. 2). The required fidelity level and reducing the number of physical tests during development can be achieved by building a reliable and repeatable protocol for Verification, Validation and Uncertainty Quantification (VVUQ) of numerical models (Refs. 3-5). UQ can be exploited to both determine how much the variability of numerical and physical parameters affect the simulation outcome and perform a calibration of numerical models. This paper aims to perform the three steps of VVUQ for a digital twin of a scaled helicopter designed for wind tunnel tests. In this study, the experimental setup and numerical model will be introduced. Then, the statistical methods implemented for each step will be explained in more detail.

Styles APA, Harvard, Vancouver, ISO, etc.

KERR, ANDREW. « Aeromechanics and man-machine integration technology opportunities for rotorcraft of the 1990s and beyond ». Dans Aircraft Design and Operations Meeting. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1989. http://dx.doi.org/10.2514/6.1989-2065.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Hiremath, Nandeesh, Dhwanil Shukla, Emily Hale, Taylor Sparacello et Narayanan Komerath. « Slung Load Amplification Detector ». Dans ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70252.

Texte intégral

Résumé :

Externally slung loads and their mission applications are becoming more common on human and autonomously piloted air vehicles. Flight speed is often limited not by the performance envelope but by the danger of divergent load oscillations. Certifying this limiting speed for every load-vehicle combination, is a huge barrier to operations. The conservatism dictated by this uncertainty may itself be life-threatening in critical applications. Computing the dynamics of slung loads for a specific load/vehicle combination has been hindered by lack of knowledge on bluffbody aeromechanics. The prevailing top-down approach is to incorporate slung load aeromechanics calculations into large comprehensive aeromechanics codes for rotorcraft. We argue for a bottom-up approach. This allows on-the-fly system identification and dynamics simulation. The Slung Load Amplification Detector (SLAD) concept provides an on-board safety system to predict, detect, avoid and alleviate divergent oscillations. SLAD is based on a knowledge base derived from wind tunnel data and simulation results including canonical geometries, as well as practical shapes. Validation of simulation results against two practical test cases lends confidence. SLAD allows reliable distinction between pseudo and absolute divergence, permitting an increase of as much as 50% speed in safe flight speed, and guidance on active alleviation of oscillations.

Styles APA, Harvard, Vancouver, ISO, etc.

Patil, Mrinalgouda, Paulo Arias, James Baeder et Anubhav Datta. « An Integrated Three-Dimensional Aeromechanical Analysis of Lift-Offset Coaxial Rotors ». Dans Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17518.

Texte intégral

Résumé :

This paper presents the first use of integrated three-dimensional (3D) aeromechanics modeling, defined as the coupling of 3D solid finite elements based comprehensive analysis (CA) with 3D Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD), to study modern lift offset coaxial rotors. The goal is to demonstrate the development of this methodology and assess its capabilities. The X3D structural dynamics solver is coupled with the UMD Mercury CFD framework for this analysis. Metaltail- a notional hingeless coaxial rotorcraft, developed as an open-access model for the U.S. Army / DoD's High Performance Computing Framework Helios is used as the test case here. The analysis is performed at a low speed transition flight and preliminary predictions of airloads and three-dimensional stresses are discussed. Modern coaxial rotors are compromised by heavy rotor hubs reducing their performance. This paper aims to demonstrate a high-fidelity capability that can help overcome this barrier through accurate predictions of 3D dynamic stresses of blade and hub.

Styles APA, Harvard, Vancouver, ISO, etc.

Gul, Seyhan, et Anubhav Datta. « Aeroelastic Loads and Stability of Swept-Tip Hingeless Tiltrotors Toward 400 knots Flutter-Free Cruise ». Dans Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16762.

Texte intégral

Résumé :

A hingeless hub tiltrotor with swept-tip blades was examined comprehensively with a new rotorcraft aeromechanics solver developed at the University of Maryland. The solver was verified with hypothetical U.S. government results and validated with Boeing M222 test data from 1972. A 20◦ sweep back from 80%R increased instability speed to 395 knots, an improvement of 70 knots. The key mechanism is the aerodynamic center shift. The trade-off is the increase in control system loads. Fundamental understanding of the physics is provided. Air resonance emerged as the critical phenomenon, not whirl flutter. Predictions in powered mode is necessary. At least first rotor flap, lag, and torsion modes need to be included. Rotor aerodynamics should use airfoil tables; wing aerodynamics is not important for air resonance. Analysis shows high speed flight is achievable with 13.5% wings but systematic wind tunnel tests with modern equipment is necessary for further validation.

Styles APA, Harvard, Vancouver, ISO, etc.

Grubb, Amanda, Rohit Jain et Marilyn Smith. « Physics of BVI-Induced Dynamic Stall on Equivalent One-Bladed and Four-Bladed Rotors ». Dans Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16719.

Texte intégral

Résumé :

Recent developments in high-fidelity CFD analyses of dynamic stall on three-dimensional, rotating systems has disrupted the classic view of dynamic stall. Visual inspection of rich flowfields generated from these studies lead research and academia subject matter experts to observe that in addition to rigid and elastic blade motion, dynamic stall may be triggered by other mechanisms, such as blade-vortex interactions, tip shocks, fluid structure coupling, and other complex phenomena associated with rotorcraft aeromechanics. The UH-60A four-bladed, articulated rotor was studied at various test points from the 2010 National FullScale Aerodynamics Complex (NFAC) 40-by-80 foot wind tunnel test. Four-bladed, loosely-coupled CFDCSD predictions were compared to one-bladed predictions using prescribed motion to isolate the effects of blade motion from the effects of complex aerodynamics associated with blade-vortex interactions (BVI) associated with dynamic stall. From these, further insights into the role of BVI on rotor blade separation and the onset of dynamic stall.

Styles APA, Harvard, Vancouver, ISO, etc.

Kumar, Sumeet, Dominik Komp, Manfred Hajek et Jürgen Rauleder. « Integrated Rotor Performance Improvement and Vibration Reduction Using Active Camber Morphing ». Dans ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/smasis2019-5588.

Texte intégral

Résumé :

Abstract This paper discusses open-loop and closed-loop active control investigations of a full-scale Bo 105 helicopter rotor with active camber morphing. The potential of an active camber morphing concept to reduce non-rotating vibratory hub loads and rotor power using active control was investigated. The mechanism employed was a dynamically actuated airfoil camber morphing concept known as Fish Bone Active Camber (FishBAC) that smoothly deforms the camber over the aft section of the airfoil. A comprehensive rotorcraft aeromechanics analysis was used that modeled the blade elastic motion using one-dimensional finite beam elements combined with multibody dynamics. 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 vibration. 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 4.3% and overall vibratory hub loads by 27%. Additionally, a closed-loop adaptive multicyclic controller was used to identify the potential of this morphing concept for hub vibration reduction using multicyclic active control inputs. Active camber actuation using a sum of four control harmonic inputs, i.e. 1-4P, resulted in a maximum hub vibration reduction of 50%.

Styles APA, Harvard, Vancouver, ISO, etc.

BIR, GUNJIT, et INDERJIT CHOPRA. « Aeromechanical Stability of Rotorcraft With Advanced Geometry Blades ». Dans 34th Structures, Structural Dynamics and Materials Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1993. http://dx.doi.org/10.2514/6.1993-1304.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Park, SunHoo, Byeong Kim, TaeYong Chun et SangJoon Shin. « Structural Optimization of a Co-Axial Compound Rotorcraft by using Three-Dimensional Finite Element Representation ». Dans Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17485.

Texte intégral

Résumé :

A three-dimensional detailed design procedure is proposed for the internal layout optimization of a co-axial compound rotorcraft. The present design procedure consists of the following two phases. In its first phase, the detailed three-dimensional configuration is obtained by a robust procedure. This procedure constructs the detailed internal layout based on the structural integrity and aeromechanical stability analysis. Along with such, structural optimization is attempted, and the structural weight will become more precise than that estimated by the trend formula. It is found that the first phase has the capability to predict the component weight accurately. And then, the second phase is performed for estimating the more realistic internal layout. The present procedure accounts the volume of the components and the internal layout will be reconstructed by including the realistic component volume. By applying those phases, the internal layout of the compound rotorcraft will become more realistic.

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Rotorcraft aeromechanics"

Wissink, Andrew, Jude Dylan, Buvana Jayaraman, Beatrice Roget, Vinod Lakshminarayan, Jayanarayanan Sitaraman, Andrew Bauer, James Forsythe, Robert Trigg et Nicholas Peters. New capabilities in CREATE™-AV Helios Version 11. Engineer Research and Development Center (U.S.), juin 2021. http://dx.doi.org/10.21079/11681/40883.

Texte intégral

Résumé :

CREATE™-AV Helios is a high-fidelity coupled CFD/CSD infrastructure developed by the U.S. Dept. of Defense for aeromechanics predictions of rotorcraft. This paper discusses new capabilities added to Helios version 11.0. A new fast-running reduced order aerodynamics option called ROAM has been added to enable faster-turnaround analysis. ROAM is Cartesian-based, employing an actuator line model for the rotor and an immersed boundary model for the fuselage. No near-body grid generation is required and simulations are significantly faster through a combination of larger timesteps and reduced cost per step. ROAM calculations of the JVX tiltrotor configuration give a comparably accurate download prediction to traditional body-fitted calculations with Helios, at 50X less computational cost. The unsteady wake in ROAM is not as well resolved, but wake interactions may be a less critical issue for many design considerations. The second capability discussed is the addition of six-degree-of-freedom capability to model store separation. Helios calculations of a generic wing/store/pylon case with the new 6-DOF capability are found to match identically to calculations with CREATE™-AV Kestrel, a code which has been extensively validated for store separation calculations over the past decade.

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!