GB596784A - Improvements in and relating to elastic fluid turbines - Google Patents

Abstract

596,784. Elastic-fluid turbines. BRITISH THOMSON-HOUSTON CO., Ltd. Aug. 28, 1944, No. 16256. Convention date, Aug. 27, 1943. Class 110 (iii)] The nozzle and rotor passages of an elasticfluid turbine are shaped so as to ensure pure impulse working. The nozzle blades 45, Fig. 5, are warped to form exit angles increasing from root to tip, and the inner and outer walls 48, 49 form parts of a toroidal shell, the warp of the blades and the curvature of the walls being such as to cause the fluid to leave the nozzle at a velocity which whilst varying in direction is constant in magnitude over the radial depth of the nozzle, thus eliminating radial pressure gradients. The rotor blades 50 are warped to form inlet angles increasing from root to tip at a rate greater than that of the nozzle blade exit angles, the cross-sectional area of flow being constant from inlet to outlet. The exit angles of the rotor blades decrease from root to tip. Each intermediate nozzle passage has the outer wall formed with curvatures 56, 58 to lead the working fluid smoothly to the toroidal exit portion 57, the inner wall being similarly formed. Intermediate nozzle blades 53 are warped similarly to the blades 45 and are precede by an annular channel 59. The toroidal shape of the inner and outer nozzle walls may be approximated by making these surfaces conical, the apieces of the cones being located on the turbine axis. In a modification, Fig. 6, the inner and outer walls 64, 65 of the rotor passages are curved to form continuations of the toroidal surfaces 66, 67 of the walls of the preceding nozzle passages, so as to shorten the intermediate nozzle passages 69.