In this paper a numerical study is presented with the aim of evaluating the performance output of three Vertical Axis Wind Turbine (VAWT) configurations. Here using Computational Fluid Dynamics (CFD) a two-dimensional Multi Reference Frame (MRF) approach has been used to perform steady state simulations. For this purpose an inlet velocity of 4m/s has been used along with rotor blade Tip Speed R...

Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbin...

Abstract. The behaviour of a rooftop-mounted generic H-rotor Darrieus vertical-axis wind turbine (H-VAWT) is investigated numerically in realistic urban terrain. interaction the atmospheric boundary layer with different buildings, topography, and vegetation present environment leads to highly turbulent-inflow conditions continuously changing inclination direction. Consequently, all these factor...

Pitch regulation plays a significant role in improving power performance and achieving output control wind turbines. The present study focuses on novel, pitch-regulated vertical axis turbine (VAWT) with inclined pitch axes. effect of two parameters (the fold angle the incline angle) instantaneous aerodynamic forces overall straight-bladed VAWT under tip-speed ratio 4 is investigated using an ac...

This paper describes some properties of a certain fibered hyperbolic 3manifold which arises ”in nature”; that is, as the cover of a closed manifold constructed by other means. Among other things, the main theorem answers in the affirmative the question of whether it is possible for a fibered hyperbolic manifold to be a double across a connected surface. (We first heard this question from Alan R...

The concept of doubling, introduced around 1840 by Hamilton and Graves, associates with any quadratic algebra A over a field k of characterstic not 2 its double V(A) = A×A, with multiplication (w, x)(y, z) = (wy− z̄x, xȳ + zw). It yields an endofunctor on the category of all quadratic k-algebras which is faithful but not full. We study in which respect the division property of a quadratic k-alge...