This paper shows a method to compute the chord and twist distributions in wind power blades. The distributions are computed to maximize the mean expected power depending on the Weibull wind distribution at a specific site. This approach avoids assumptions about optimal attack angle related to the ratio between the lift to drag coefficients. To optimize chord and twist distributions, an efficien...

Accurate simulations of the aerodynamic performance of vertical-axis wind turbines pose a significant challenge for computational fluid dynamics methods. The aerodynamic interaction between the blades of the rotor and the wake that is produced by the blades requires a high-fidelity representation of the convection of vorticity within the wake. In addition, the cyclicmotion of the blades induces...

Vertical axis wind turbines (VAWTs) are gradually receiving more and more interest due to their lower sensitivity to the yawed wind direction. Compared with straight blades VAWT, blades with a certain helicity show a better aerodynamic performance and less noise emission. Nowadays computational fluid dynamics technology is frequently applied to VAWTs and gives results that can reflect real flow...

This paper presents an integrated method for designing airfoil families of large wind turbine blades. For a given rotor diameter and tip speed ratio, the optimal airfoils are designed based on the local speed ratios. To achieve high power performance at low cost, the airfoils are designed with an objective of high Cp and small chord length. When the airfoils are obtained, the optimum flow angle...

High angle of attack aerodynamics is inherently associated with: • separated flows, and thus nonlinear aerodynamics > one of the key aspects is the interaction of components, and in particular, vortex flows (vortex bursting is also an important effect) • heavily dependent on wind tunnel testing • connected with flight simulation to ensure good handling qualities > this means that large amounts ...

Wind energy is one of the renewable resources which clean and sustainable wind turbine used for harnessing from wind. The blades are key components a to convert into rotational energy. Recently, wingtip devices in horizontal axis (HAWT), decreases vortex drag, while increases lift thereby improve performance turbine. In present study, winglet at tip an NREL phase VI blade. Solidworks, Pointwise...

Tidal turbines experience large load fluctuations due to the unsteady environment and shear in tidal flow. Mitigating these without affecting mean would result lower capital operational costs. In this paper we discuss how could be achieved through blades that passively elastically adapt their camber angle of attack counteract flow conditions. Firstly, underlying principles thrust mitigation. We...

Numerical investigation was performed on NACA 0015 which is a symmetric airfoil. Pressure distribution and then lift and drag forces are verified. Changing of ground clearance was a considerable point. Also the angle of attack was changed from 0° to 10°. Pressure coefficient reaches its higher amounts on the wing lower surface when the ground clearance diminishes. Increment of the angle of atta...

background:   to compare the results of two different ways of distal femoral osteotomy stabilization in patients suffering from genuvalgum: internal fixation with plate, and casting. methods:   in a non-randomized prospective study, after distal femoral osteotomy with the zigzag method, patients were divided into two groups: long leg casting, and internal fixation with blade plate. for all pati...