Abstract
The authors have developed a new type of micro-hydropower cross flow turbine for application to a straight drop spillway
in an irrigational channel. In this cross-flow turbine, water flows directly into the nozzle inlet instead of through a
closed conduit. In the present study, the flow conditions in the runner chamber and draft tube are empirically investigated in
terms of the hydraulic performance of the developed turbine. When the flow rate in the channel is less than the limit value,
large amount of atmosphere is always vacuumed via the nozzle and the turbine performances change drastically. The limit
flow rate could be indicated clearly by using flow rate coefficient which normalized by using head standardized on runner
inlet height and runner chamber pressure. Further, the turbine efficiency could be increased in the high runner speed range
by using round wall draft-tube because of improvement of angular momentum change.
