Results 31 to 40 of about 36,023 (164)

Theoretical Calculation of Wind (Or Water) Turbine: Extending the Betz Limit

open access: yes, 2021
The Betz limit sets a theoretical upper limit for the power production by turbines expressed as a maximum power coefficient of 16/27. Betz’s theory is accurate and it is based on the calculation of kinetic energy.
Pierre Lecanu   +3 more
openaire   +2 more sources

A large-eddy simulation analysis of collective wind farm axial-induction set points in the presence of blockage [PDF]

open access: yesWind Energy Science
Over the past few years, numerous studies have shown the detrimental impact of flow blockage on wind farm power production. In the present work, we investigate the benefits of a simple collective axial-induction set point strategy for power maximization ...
T. Delvaux, J. Meyers
doaj   +1 more source

Stable states of perturbed Markov chains [PDF]

open access: yes, 2016
Given an infinitesimal perturbation of a discrete-time finite Markov chain, we seek the states that are stable despite the perturbation, \textit{i.e.} the states whose weights in the stationary distributions can be bounded away from $0$ as the noise ...
Betz, Volker, Roux, Stephane Le
core   +2 more sources

Theoretical Analysis of Shrouded Horizontal Axis Wind Turbines

open access: yesEnergies, 2017
Numerous analytical studies for power augmentation systems can be found in the literature with the goal to improve the performance of wind turbines by increasing the energy density of the air at the rotor.
Tariq Abdulsalam Khamlaj   +1 more
doaj   +1 more source

An Investigation of a Mathematical Model for the Internal Velocity Profile of Conical Diffusers Applied to DAWTs

open access: yesAnais da Academia Brasileira de Ciências, 2015
The Diffuser Augmented Wind Turbines (DAWTs) have been widely studied, since the diffusers improve the power coefficient of the wind turbine, particularly of small systems.
DISTERFANO L.M. BARBOSA   +5 more
doaj   +1 more source

Power Coefficient for Large Wind Turbines Considering Wind Gradient Along Height

open access: yesEnergies
The Betz constant is the well-known aerodynamic limit of the maximum power which can be extracted from wind using wind turbine technologies, under the assumption that the wind speed is uniform across a blade disk. However, this condition may not hold for
Saroj Biswas, Jim Shih-Jiun Chen
doaj   +1 more source

Non-Empirical BEM Corrections Relating to Angular and Axial Momentum Conservation

open access: yesEnergies, 2019
The Blade-Element Momentum (BEM) model for Horizontal-Axis Wind Turbines (HAWTs), although extremely useful, is known to be approximate due to model formulation insufficiencies, for which add-ons and corrections have been formulated over the past many ...
Søren Hjort
doaj   +1 more source

The Lanchester–Betz–Joukowsky limit

open access: yesWind Energy, 2007
AbstractThe maximum efficiency of an ideal wind turbine rotor is well known as the ‘Betz limit’, named after the German scientist that formulated this maximum in 1920. In 1976, Bergey showed that the British scientist Lanchester derived the same maximum already in 1915. Betz and Lanchester were representatives of leading aerodynamic research schools in
openaire   +1 more source

Variable Pitch Darrieus Water Turbines

open access: yesJournal of Fluid Science and Technology, 2008
In recent years the Darrieus wind turbine concept has been adapted for use in water, either as a hydrokinetic turbine converting the kinetic energy of a moving fluid in open flow like an underwater wind turbine, or in a low head or ducted arrangement ...
Brian KIRKE, Leo LAZAUSKAS
doaj   +1 more source

Non‐uniform velocity distribution effect on the Betz–Joukowsky limit

open access: yesWind Energy, 2012
ABSTRACTA simple analytic correction is derived for the maximum efficiency of an ideal wind turbine rotor, the Betz–Joukowsky limit. The analytic correction accounts for the effect that the non‐uniform atmospheric boundary layer velocity distribution has on the Betz–Joukowsky derivation.
Leonardo P. Chamorro, R.E. A Arndt
openaire   +1 more source

Home - About - Disclaimer - Privacy