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The present work numerically explores the performance characteristics of Darrieus turbine with NTU-20-V and NACA 0018 airfoils. The NTU-20-V airfoil was carved out to enhance the fatigue life of the aluminium extruded blades by reinforcing with glass fiber material in standard shapes. The earlier studies by the authors include conceiving the airfoil profile through genetic algorithm optimization followed...
This paper presents the comparison of power captured by vertical and horizontal axis wind turbine (VAWT and HAWT). According to Betz, the limit of maximum coefficient power (CP) is 0.59. In this case CP is important parameter that determines the power extracted by a wind turbine we made. This paper investigates the impact of wind speed variation of wind turbine to extract the power. For VAWT we used...
In this paper, a complete numerical simulation model of helicopter flight dynamics was established. The modeling of the main aerodynamic components of the helicopter and the aerodynamic interference are taken into account, and the modeling methods of the airfoil aerodynamic model, the induced velocity model and the waving movement model are discussed in detail. Based on the hierarchical and modular...
We develop a theoretical power consumption model for multi-rotor Unmanned Aircraft Systems (UAS), estimate the model parameters, and validate it by flying an IRIS+ quadrotor UAS and measuring its energy consumption experimentally. The model is derived from the helicopter literature. Such models are required to create UAS flight planning systems.
Control of aerodynamic loads is a crucial issue in keeping wind energy economically competitive with traditional energy sources. This paper continues the investigation of the use of Iterative Learning Control (ILC) for load control in wind turbines with smart devices on rotor blades. A relatively simple computational fluid dynamics model is used to simulate the flow past an airfoil. Assuming no actuator...
The main objective of this research is to optimize the diffuser design of Diffuser Augmented Wind Turbine (DAWT). Specifically, this study investigates the effect of different shapes of diffusers to develop the suitable diffuser parameter for the wind turbine power enhancement. For that purpose, two diffuser cases have been recommended as an effective design in increasing wind speed, using a validated...
The rotor dimensioning of a wind turbine is essentially based on aerodynamic theory to define the parameters affecting its overall performance. The blade element momentum theory (BEM) has been widely used as a tool for the design of wind turbine blade. An existing airfoil shape with known chord and twist can be input to BEM to calculate the efficiency. On the other hand, if we set airfoil as unknown...
Comprehensive study on control stability analysis before controller design is an indispensable important step for any flight system. In this paper, frequency modal responses and relative input-output controllability are analyzed quantitatively to provide valid instruction for structure improvement. In this project, tilting electric ducted fan (EDF) system is devised for an unmanned tandem ducted fan...
In this paper the problem of active control of vibrations in helicopters is faced in a very general way. Precisely, we consider the case when the aircraft moves according to a possibly varying forward velocity. The problem is then more complex that the one encountered in hover or in forward flight. We tackle the general problem by means of an LPV (Linear Parametrically-Varying) approach, complemented...
The use of modelling and simulation in any sphere of work must be tempered by an understanding of the extent to which such models are valid. The conditions under which modelling deficiencies and approximations cause accuracy to be lost must be clearly defined so that research or experimental investigations using such models yield meaningful results. This paper considers the validation of a large-scale...
This paper addresses the problem of path following control system design for model-scale helicopters. The presented design strategy builds on the definition of an adequate generalized error space for expressing the vehicle's dynamics and kinematics. The path following problem is cast and solved in the framework of gain scheduling control theory, using the D-methodology. The resulting control law ensures...
Force and torque generation mechanisms for an unconventional tandem ducted fan aircraft are investigated. Numerical techniques are implemented to obtain quasi-steady thrust, numerical integration of nonlinear equations of motion and trim iteration process, respectively. The comprehensive nonlinear model is derived and simplified to linear approximations at different flight conditions for stability...
Gyroplane is becoming popular these days for its characters of security, reliable and simple operation. Modeling is the first step that put mathematical theory into engineering studies such as aircraft stability, control and handling qualities. Considering the variable rotoring speed, propeller, tail aero forces and moment, this paper explores the mathematical model of an unmanned mode gyroplane based...
Smart rotors integrated into the blades of large-scale turbines offer, when used in conjunction with collective and individual pitch control, the potential to significantly improve aerodynamic performance and load control. Of the four main ways to modify the lift on the blades, this work seeks to modify the blade section aerodynamics by damping perturbations in the lift using circulation control by...
This paper proposes a new kind of disk-typed autonomous aerial robot, which can overcome some shortcomings of the structure of the ducted-fan aircraft. In order to derive the mathematical model of the disk-typed autonomous aerial robot (DAAR), the Newton-Euler equations have been employed. After that, this model is verified by numerical simulations, the outcome is in line with the physical fact. The...
The focus of most low wind turbine designers is how to maximize power extraction. Designing horizontal axis turbine for relatively low average wind speed requires power extraction at high tip speed ratio obtained at high angle of attack. These high angles occur at low Reynolds numbers which makes it even more difficult to generate sufficient lift to turn the blades. Therefore, the shape of the rotor...
Method for numerical modeling of scattering characteristics of air targets with turboprop engines including secondary modulation spectra of signals reflected by stated objects is considered. Earlier developed by authors high-frequency asymptotic method [1, 2] based on estimation of contributions of the smooth and edged segments of object surface to scattered field is used for modeling. Results of...
This article provides a tutorial introduction to modeling, estimation, and control formultirotor aerial vehicles that includes the common four-rotor or quadrotor case.
Profile of the NACA0015 airfoil was used as the basic section of a novel spiral vertical axis wind rotor blade. Three-dimensional unsteady simulation was carried out for the flow field around the presented wind rotor using the commercial CFD software Fluent. Chord length, rotating speed and other aerodynamic performance parameters of the wind rotor were focused. The results indicate that the intensity...
Energy extraction from tidal currents using marine current turbines has been gaining attention in recent years. In this paper, the design and optimization of a horizontal axis turbine is proposed to harvest available ocean kinetic energy from very low flow regimes, area of application which was not previously addressed in the literature. Accordingly, a horizontal axis marine current turbine is modeled...
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