Linear and nonlinear models in wind resource assessment and wind turbine micro-siting in complex terrain

The current trend of increasing the electricity production from wind energy has led to the installation of wind farms in areas of greater orographic complexity, raising doubts on the use of simple, linear, mathematical models of the fluid flow equations, so common in the wind energy engineering. The present study shows how conventional techniques, linear models and cup anemometers, can be combined with flow simulation by computational fluid dynamics techniques (nonlinear models) and measurements by sonic anemometers, and discuss their relative merits in the characterisation of the wind over a coastal region—a cliff over the sea. The computational fluid dynamic techniques were particularly useful, providing a global view of the wind flow over the cliff and enabling the identification of separated flow regions, clearly unsuitable for installation of wind turbines. These locations display a pulsating flow, with periods between 1 and 7min, in agreement with sonic anemometer measurements, and both a turbulence intensity and a gust factor well above the wind turbine design conditions.The authors acknowledge the support of the Portuguese Foundation for Science and Technology (FCT), under research Project TURBWIND (POCI/ENR/60965/2004). Data from the field experiment were kindly supplied by EEM-Empresa de Electricidade da Madeira, SA.info:eu-repo/semantics/publishedVersio

Complex terrain experiments in the New European Wind Atlas

The New European Wind Atlas project will create a freely accessible wind atlas covering Europe and Turkey, develop the model chain to create the atlas and perform a series of experiments on flow in many different kinds of complex terrain to validate the models. This paper describes the experiments of which some are nearly completed while others are in the planning stage. All experiments focus on the flow properties that are relevant for wind turbines, so the main focus is the mean flow and the turbulence at heights between 40 and 300 m. Also extreme winds, wind shear and veer, and diurnal and seasonal variations of the wind are of interest. Common to all the experiments is the use of Doppler lidar systems to supplement and in some cases replace completely meteorological towers. Many of the lidars will be equipped with scan heads that will allow for arbitrary scan patterns by several synchronized systems. Two pilot experiments, one in Portugal and one in Germany, show the value of using multiple synchronized, scanning lidar, both in terms of the accuracy of the measurements and the atmospheric physical processes that can be studied. The experimental data will be used for validation of atmospheric flow models and will by the end of the project be freely available. This article is part of the themed issue ‘Wind energy in complex terrains’

Mixing in non-reacting gas turbine combustor flows

SIGLEAvailable from British Library Document Supply Centre- DSC:DX188158 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Coriolis induced compressibility effects in rotating shear layers

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2D turbulence on a bounded domain with no-slip walls

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Two-dimensional turbulence on a confined domain with no-slip walls

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Stereo-PIV measurements in turbulent rotating convection

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