Historical overview of cross-flow turbine

The historical development of the cross-flow turbine both theoretically and experimentally is discussed. Specific references are made to the most recent work done on the machine at Colorado State University. The turbine has unique and inherent advantages in that nozzle and runner discs can be made of steel plate and the blades can be cut from steel pipe, making design and construction simple. The most valuable feature of the cross-flow turbine has been said to be the favorable shape of its efficiency curve, particularly with the use of divided guide vanes. This is particularly important for small run-of-the-river power plants. Objects entering the blades in the first stage tend to be washed out after half a revolution of the runner by the outgoing water, assisted by centrifugal force. The first cost of a cross-flow machine is less than that of any kind of turbine used for low head hydropower. The maintenance and operating cost of the cross-flow is lower than that of any other turbine. Suitable specific speed for use on generators, corn mills, saw mills, farm machinery, workshops, and pumping installations is available. There is a possible effect on stream ecology through increasing dissolved oxygen content. Adaptability to draft tubes, freedom from cavitation and low civil work costs are also significant factors. 14 references, 4 figures.