Wind potential evaluation around isolated pitched roof buildings

Abstract

The knowledge of wind field characteristics around buildings is very useful in a variety of applications such as energy supply by means of a domestic wind turbine. In this paper, results of a wind study around a conventional pitched roof building are given in order to choose the best location and therefore to maximize a micro-wind turbine production. Numerical results on a bluff body (cube) have been performed by means of computational fluid dynamics techniques and the Reynolds Averaged Navier-Stokes approach has been used to model the flow. Several turbulence models coupled to different near-wall treatments have been tested and have thus allowed one to determine the optimal configuration. Numerical model validation through the experimental data available in literature has made it possible to extend the study to a cube equipped with a pitched roof. Both sets of results thus obtained have allowed one to discriminate the effects from this particular element. Some of the computed data will be given in this paper in order to highlight the most significant regions relative to wind potential for a range of wind incidence angles. Some over speed areas have been found in the vicinity of the pitched cube for low altitudes. Finally, a simple method to map wind potential around buildings is proposed and a case study is presented. It deals with wind potential estimation for an isolated pitched roof building in Valenciennes (North of France). It is shown that some areas are beneficial for a micro wind turbine installation, even close to the building. V C 2015 AIP Publishing LLC. [http://dx. NOMENCLATURECp pressure coefficient Ei incident energy (kW hÁyear À1 Ám À2 ) Ep produced energy (kW hÁyear À1 Ám À2 ) f U velocity sector in wind rose f c angular sector in wind rose h height of the cube (m) k turbulent kinetic energy (m 2 s À2 ) P pressure (Pa) U mean velocity component in x-direction (m s À1 ) u* dimensionless velocity in the x direction X R reattachment length at the top of the cube (m) X W reattachment length in the wake of the cube (m) Yþ dimensionless wall distance a) Author to whom correspondence should be addressed. Electronic mail: nachida.bourabaa@univ-valenciennes.fr. Tel.: þ33 327 511 224. Fax: 33 327 511 200. b) Electronic addresses: eric.delacourt@univ-valenciennes.fr and jean-luc.menet@univ-valenciennes.fr 1941-7012/2015/7(2)/023111/17/$30.00 V C 2015 AIP Publishing LLC 7, 023111-1 JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY 7, 023111 (2015)Greek letters a angle between wind turbine position and the roof ridge b angle between the wind direction and the roof ridge c angle between the wind direction and the north e dissipation rate of k (m 2 s À3 ) l dynamic viscosity l t turbulent viscosity q air density (kg m À3 ) r s constant of the turbulence model

A Magnus Wind Turbine Power Model Based on Direct Solutions Using the Blade Element Momentum Theory and Symbolic Regression

“…Sedaghat [5] concluded that the Magnus wind turbine power coefficient is not as yet promising for urban environments, which includes highly variable flow direction, low speeds and high shear [6]. To improve this performance, local configurations may be considered as proposed by Bourabaa et al [7].…”

Effects of roof slope and wind direction on wind pressure distribution on the roof of a square plan pyramidal low-rise building using CFD simulation

“…However, in spite of its specific features, very limited research work has been carried out in this specific area of wind load on pyramidal roof buildings (Roy et al 2018b;Roy et al 2018a). Maximum studies in this field are concerned with low-rise buildings with canopy roof (Roy 2010, a) gable roof, hip roof (Ahmad and Kumar 2001;Irtaza et al 2015;Tecle et al 2015;Habte et al 2017), isolated pitched roof (Bourabaa et al 2015), tall chimney (Verma et al 2015;Khan and Roy 2017) and tall structures (Paul and Dalui 2008;Amin and Ahuja 2014;Kar and Dalui 2016;P. Martinez-Vazquez 2016;Sanyal and Kumar 2018), and aim to provide information about the consistency of performance and the upgrading of design economy (Isyumov 1999).…”