STRAIGHT-FLOW TURBINE.

Abstract

Work done in Great Britain since 1966 on the straight-flow unit is described. The problems to be solved were: rim seals; waterproofing and cooling of generator; support of rotor; and rim mounting, allowing for differential expansion and for a Kaplan runner. Development work has solved the problems and indicates that the largest propeller and Kaplan straight-flow units can be built. A Kaplan design is illustrated. A comparison of the straight-flow unit with other designs indicates that it leads to considerable savings and so makes many low-head schemes and possibly tidal power economic.