this paper is an attempt to numerical modeling and experimental study of air flow in the yazdi wind-towers. wind towers has been known as one of the most effective climatic elements in iranian traditional architecture. this paper is an attempt to evaluating yazdi wind-tower to discussion the two main questions: 1. what is the role of orientation of wind-towers span, regarding to climate and hei...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

This paper is an attempt to Numerical Modeling and Experimental Study of Air Flow in the Yazdi Wind-Towers. Wind Towers has been known as one of the most effective climatic elements in Iranian traditional architecture. This paper is an attempt to evaluating Yazdi wind-tower to discussion the two main questions: 1. What is the role of Orientation of wind-towers span, regarding to climate and he...

An experimental study was conducted to characterize the dynamic wind loads and evolution of the unsteady vortex and turbulent flow structures in the near wake of a horizontal axis wind turbine model placed in an atmospheric boundary layer wind tunnel. In addition to measuring dynamic wind loads (i.e., aerodynamic forces and bending moments) acting on the wind turbine model by using a high-sensi...

PURPOSE To evaluate the in-scan and scan-rescan consistency of left ventricular (LV) in- and outflow assessment from 1) 2D planimetry; 2) 4D flow magnetic resonance imaging (MRI) with retrospective valve tracking, and 3) 4D flow MRI with particle tracing. MATERIALS AND METHODS Ten healthy volunteers (age 27 ± 3 years) underwent multislice cine short-axis planimetry and whole-heart 4D flow MRI...

In a steam power plant, the temperature of the cooling water leaving the condenser for recyclingshould decrease. This is achieved in a cooling tower. The Heller cooling tower does not require waterfor operation, thus, it is a suitable system for use in thermal power plants throughout Iran. Wind is anenvironmental factor that unfavorably affects the performance of a cooling tower. Previous studi...

Wind-tunnel experiments were carried out to better understand boundary layer effects on the flow pattern inside and above a model wind farm under thermally neutral conditions. Cross-wire anemometry was used to characterize the turbulent flow structure at different locations around a 10 by 3 array of model wind turbines aligned with the mean flow and arranged in two different layouts (inter-turb...

The Current Source Converter (CSC) technology is well suited for high power wind energy applications. Because it drives generally features like simple converter structure, smooth power injection at the grid side and excellent short circuit protection. The main drawback lays its dynamic torque response. An improved Direct Torque Control (DTC) method is proposed in this paper to overcome this dra...

An experimental study is conducted to characterize the dynamic wind loads and evolution of the turbulent vortex and flow structures in the wake of a horizontal axis wind turbine (HAWT). In addition to measuring dynamic wind loads (both aerodynamic forces and moments) acting on a wind turbine model, a high-resolution Particle Image Velocimetry (PIV) system was used to make “free-run” and phase-l...

An experimental study was conducted to investigate the performance of wind turbines sited over hilly terrains in order to elucidate the underlying physics to explore/optimize design of wind turbines sitting over complex terrains for higher power yield and better durability. The experiments were conducted in an atmospheric boundary layer wind tunnel with wind turbines sited over a two-dimensiona...