Aeroelastic analysis of helicopter rotor blade in hover using an efficient reduced-order aerodynamic model

2009 ◽  
Vol 25 (8) ◽  
pp. 1243-1257 ◽  
Author(s):  
H. Shahverdi ◽  
A.S. Nobari ◽  
M. Behbahani-Nejad ◽  
H. Haddadpour
2018 ◽  
Vol 90 (6) ◽  
pp. 937-945 ◽  
Author(s):  
Saijal Kizhakke Kodakkattu ◽  
Prabhakaran Nair ◽  
Joy M.L.

Purpose The purpose of this study is to obtain optimum locations, peak deflection and chord of the twin trailing-edge flaps and optimum torsional stiffness of the helicopter rotor blade to minimize the vibration in the rotor hub with minimum requirement of flap control power. Design/methodology/approach Kriging metamodel with three-level five variable orthogonal array-based data points is used to decouple the optimization problem and actual aeroelastic analysis. Findings Some very good design solutions are obtained using this model. The best design point in minimizing vibration gives about 81 per cent reduction in the hub vibration with a penalization of increased flap power requirement, at normal cruise speed of rotor-craft flight. Practical implications One of the major challenges in the helicopters is the high vibration level in comparison with fixed wing aircraft. The reduction in vibration level in the helicopter improves passenger and crew comfort and reduces maintenance cost. Originality/value This paper presents design optimization of the helicopter rotor blade combining five design variables, such as the locations of twin trailing-edge flaps, peak deflection and flap chord and torsional stiffness of the rotor. Also, this study uses kriging metamodel to decouple the complex aeroelastic analysis and optimization problem.


2012 ◽  
Vol 57 (2) ◽  
pp. 1-9 ◽  
Author(s):  
Bryan Glaz ◽  
Li Liu ◽  
Peretz P. Friedmann ◽  
Jeremy Bain ◽  
Lakshmi N. Sankar

The surrogate-based recurrence framework (SBRF) approach to reduced-order dynamic stall modeling associated with pitching/plunging airfoils subject to fixed or time-varying freestream Mach numbers is described. The SBRF is shown to effectively mimic full-order two-dimensional computational fluid dynamics solutions for unsteady lift, moment, and drag, but at a fraction of the computational cost. In addition to accounting for realistic helicopter rotor blade dynamics, it is shown that the SBRF can model advancing rotor shock induced separation as well as retreating blade stall associated with excessive angles of attack. Therefore, the SBRF is ideally suited for a variety of rotary-wing aeroelasticity and active/passive design optimization studies that require high-fidelity aerodynamic response solutions with minimal computational expense.


2007 ◽  
Vol 45 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Dipali Thakkar ◽  
Ranjan Ganguli

Author(s):  
R. Kashani ◽  
S. Melkote ◽  
A. Sorgenfrei

Abstract Active vibration control of helicopter rotor blade is studied. For the purpose of illustration, we have considered only flap wise vibration of a hingeless rotor blade, and modelled it, using finite element method, by 20 beam elements. The first 12 bending modes of the system are considered in the model. A H∞ controller is designed for the plant formulated as above. The result of the numerical simulation of the closed-loop system shows that the control introduces an appreciable amount of damping in the frequency region of interest. The consideration of the modelling uncertainty in the synthesis of the controller resulted in a design which is robust stable in presence of formulated model uncertainty.


Author(s):  
Mohammad Khairul Habib Pulok ◽  
Uttam K. Chakravarty

Abstract Rotary-wing aircrafts are the best-suited option in many cases for its vertical take-off and landing capacity, especially in any congested area, where a fixed-wing aircraft cannot perform. Rotor aerodynamic loading is the major reason behind helicopter vibration, therefore, determining the aerodynamic loadings are important. Coupling among aerodynamics and structural dynamics is involved in rotor blade design where the unsteady aerodynamic analysis is also imperative. In this study, a Bo 105 helicopter rotor blade is considered for computational aerodynamic analysis. A fluid-structure interaction model of the rotor blade with surrounding air is considered where the finite element model of the blade is coupled with the computational fluid dynamics model of the surrounding air. Aerodynamic coefficients, velocity profiles, and pressure profiles are analyzed from the fluid-structure interaction model. The resonance frequencies and mode shapes are also obtained by the computational method. A small-scale model of the rotor blade is manufactured, and experimental analysis of similar contemplation is conducted for the validation of the numerical results. Wind tunnel and vibration testing arrangements are used for the experimental validation of the aerodynamic and vibration characteristics by the small-scale rotor blade. The computational results show that the aerodynamic properties of the rotor blade vary with the change of angle of attack and natural frequency changes with mode number.


AIAA Journal ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 524-535 ◽  
Author(s):  
Yong Oun Han ◽  
J. Gordon Leishman

2016 ◽  
Author(s):  
Constantin Rotaru ◽  
Ionică Cîrciu ◽  
Doru Luculescu

2014 ◽  
Vol 51 (5) ◽  
pp. 1422-1431 ◽  
Author(s):  
Patrick Moser ◽  
Silvestro Barbarino ◽  
Farhan Gandhi

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