Inlet Nozzle Effect on Turbine Performance and Self-Starting Characteristics of Darrieus-Type Hydro Turbine for Extra-Low Head Hydropower Utilization

A two dimensional Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2m.Though a hydro turbine system consists of an intake, runner section and draft tube for higher efficiency operation, it wasfound in previous study that a draft tube and side-wall casings of runner section could be removed with improving turbineperformance by installation of an inlet nozzle. In the present paper, first, effects of inlet nozzle width and positions on turbineperformance are experimentally examined considered at first. After clarifying the optimum inlet nozzle, performancesof four 4 bladed Darrieus-type turbine with the simplified geometry are investigated and are discussed in terms of flow ratevariation and self-starting characteristics.