Design optimization of helicopter rotor using kriging

2018 ◽  
Vol 90 (6) ◽  
pp. 937-945 ◽  
Author(s):  
Saijal Kizhakke Kodakkattu ◽  
Prabhakaran Nair ◽  
Joy M.L.
Keyword(s):  
Rotor Blade ◽  
Optimization Problem ◽  
Torsional Stiffness ◽  
Helicopter Rotor ◽  
Vibration Level ◽  
Content Type ◽  
Aeroelastic Analysis ◽  
Kriging Metamodel ◽  
Helicopter Rotor Blade ◽  
Trailing Edge Flaps

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.

Vibration reduction of helicopter with trailing-edge flaps at various flying conditions

2016 ◽  
Vol 231 (4) ◽  
pp. 770-784 ◽  
Author(s):  
SK Kodakkattu ◽  
ML Joy ◽  
K Prabhakaran Nair
Keyword(s):  
Rotor Blade ◽  
Torsional Stiffness ◽  
Trailing Edge ◽  
Control Power ◽  
Surface Method ◽  
Solidity Ratio ◽  
Helicopter Rotor Blade ◽  
Trailing Edge Flaps ◽  
Trailing Edge Flap ◽  
Improved Design

The aim of this study is to find the optimal torsional stiffness and trailing-edge flap locations of the helicopter rotor blade for minimum vibration and flap control power at flap lengths of 6% and 9% of the rotor-blade length. A three level orthogonal array based response surface method using polynomial functions is used to describe both vibration and flap control power. Pareto points minimizing hub vibration and flap control power are found at flap lengths of 6% and 9% of the rotor length. This study also explores the variation in rotor hub vibration and flap control power with flying conditions such as the advance ratio and the thrust-to-solidity ratio at the optimum design points. This gives a useful improved design with about a 60% decrease in hub vibration with a penalization of increased flap power at the normal flying regime of rotor-craft flight.

scholarly journals Identification of Flap Motion Parameters for Vibration Reduction in Helicopter Rotors with Multiple Active Trailing Edge Flaps

2011 ◽  
Vol 18 (5) ◽  
pp. 727-745 ◽  
Author(s):  
Uğbreve;ur Dalli ◽  
Şcedilefaatdin Yüksel
Keyword(s):  
Rotor Blade ◽  
Helicopter Rotor ◽  
System Response ◽  
Trailing Edge ◽  
Blade Root ◽  
Helicopter Rotor Blade ◽  
Blade Vibrations ◽  
Trailing Edge Flaps ◽  
Trailing Edge Flap ◽  
Blade Loads

An active control method utilizing the multiple trailing edge flap configuration for rotorcraft vibration suppression and blade loads control is presented. A comprehensive model for rotor blade with active trailing edge flaps is used to calculate the vibration characteristics, natural frequencies and mode shapes of any complex composite helicopter rotor blade. A computer program is developed to calculate the system response, rotor blade root forces and moments under aerodynamic forcing conditions. Rotor blade system response is calculated using the proposed solution method and the developed program depending on any structural and aerodynamic properties of rotor blades, structural properties of trailing edge flaps and properties of trailing edge flap actuator inputs. Rotor blade loads are determined first on a nominal rotor blade without multiple active trailing edge flaps and then the effects of the active flap motions on the existing rotor blade loads are investigated. Multiple active trailing edge flaps are controlled by using open loop controllers to identify the effects of the actuator signal output properties such as frequency, amplitude and phase on the system response. Effects of using multiple trailing edge flaps on controlling rotor blade vibrations are investigated and some design criteria are determined for the design of trailing edge flap controller that will provide actuator signal outputs to minimize the rotor blade root loads. It is calculated that using the developed active trailing edge rotor blade model, helicopter rotor blade vibrations can be reduced up to 36% of the nominal rotor blade vibrations.

Vibration Analysis of a Composite Helicopter Rotor Blade at Hovering Condition

2016 ◽  
Author(s):  
Pratik Sarker ◽  
Colin R. Theodore ◽  
Uttam K. Chakravarty
Keyword(s):  
Mathematical Model ◽  
Rotor Blade ◽  
Structural Integrity ◽  
Initial Conditions ◽  
Helicopter Rotor ◽  
Mode Shapes ◽  
Vibration Level ◽  
Cross Sectional ◽  
Helicopter Rotor Blade ◽  
The Mathematical Model

The helicopter is an essential and unique means of transport nowadays and needs to hover in space for considerable amount of time. During hovering flight, the rotor blades continuously bend and twist causing an increased vibration level that affects the structural integrity of the rotor blade leading to ultimate blade failure. In order to predict the safe allowable vibration level of the helicopter rotor blade, it is important to properly estimate and monitor the vibration frequencies. Therefore, the mathematical model of a realistic helicopter rotor blade composed of composite material, is developed to estimate the characteristics of free and forced bending-torsion coupled vibration. The cross-sectional properties of the blade are calculated at first and are then included in the governing equations to solve the mathematical model. The natural frequencies and mode shapes of the composite helicopter rotor blade are evaluated for both the nonrotating and rotating cases. The time-varying bending and torsional deflections at the helicopter rotor blade tip are estimated with suitable initial conditions. The validation of the model is carried out by comparing the analytical frequencies with those obtained by the finite element model.

H ∞ Control of Smart Structure Helicopter Rotor Blade

1991 ◽  
Author(s):  
R. Kashani ◽  
S. Melkote ◽  
A. Sorgenfrei
Keyword(s):  
Rotor Blade ◽  
Active Vibration Control ◽  
Region Of Interest ◽  
Smart Structure ◽  
Helicopter Rotor ◽  
Appreciable Amount ◽  
Modelling Uncertainty ◽  
Helicopter Rotor Blade ◽  
Active Vibration ◽  
Bending Modes

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.

An Investigation of the Aerodynamic and Vibration Behavior of a Helicopter Rotor Blade

2020 ◽  
Author(s):  
Mohammad Khairul Habib Pulok ◽  
Uttam K. Chakravarty
Keyword(s):  
Rotor Blade ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Scale Model ◽  
Helicopter Rotor ◽  
Small Scale ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Analysis ◽  
Helicopter Rotor Blade

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.

Investigation of Helicopter Rotor-Blade-Tip-Vortex Alleviation Using a Slotted Tip

AIAA Journal ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 524-535 ◽  
Author(s):  
Yong Oun Han ◽  
J. Gordon Leishman
Keyword(s):  
Rotor Blade ◽  
Tip Vortex ◽  
Helicopter Rotor ◽  
Helicopter Rotor Blade ◽  
Blade Tip
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