Analysis of the flow condition in a cross flow turbine

Abstract

Energy insufficiency in developing countries arise when the locally available resources are discarded. Nepal having a huge potential in rural electrification will intensify through the development of Micro Hydro turbines. Cross flow type of hydro turbines are extensively used in micro hydropower in rural areas of Nepal. An experiment for efficiency measurement and flow analysis has been performed in cross flow turbine which was installed in The Waterpower Laboratory at the Norwegian University of Science and Technology, NTNU. Efficiency was measured for various head, nozzle opening and speed to find the best efficiency point. The flow condition in the cross flow turbine at different performance was recorded. A high speed camera FASTCAM SA5 was used to get the better flow visualization at the best efficiency point which was 77.7 % in 5m head with 80% nozzle opening at rotational speed of 350rpm. Various discussion is made on turbine performance for varying head, speed and nozzle opening. This paper is based on the flow pattern of cross-flow turbine between two stages visualized through high speed camera and compare them with theoretical velocity vectors.