Experimental analysis of cross-flow wind turbine with omni-directional multi-nozzle

Abstract

Using guiding devices is a method for increasing the efficiency of vertical wind turbines. The main problem of these devices is the hydraulic losses that occur from shading the turbine runner. Тhe geometry of the guide apparatus must ensure independence from the wind direction and allow free passage of the airflow through the blade cascade of the runner. This paper presents the results of a physical and numerical study of a cross-flow vertical wind turbine with an omni-directional guiding multi-nozzle. The task of the study is to determine the influence of the multi-nozzle on the efficiency of the turbine when the airflow changes its direction. The idea is inspired by the kinematics of the flow through the guide nozzle and runner of the cross-flow water turbine. The experiments were conducted in the Laboratory of Hydro Power and Hydraulic Turbomachinery (HEHT Lab) at the Technical University of Sofia. The obtained results are showing the influence of the multi-nozzle on the performance of the cross-flow wind turbine. They favour the selection of a suitable omni-directinoal guiding device for vertical axis wind turbines.