| 摘要 |
739,935. Turbines. GENERAL ELECTRIC CO. Feb. 15, 1954, No. 4413/54. Class 110 (3). A diffuser for the discharge side of a gas turbine comprises a pair of concentrically arranged diverging walls 11, 12 defining an annular passage, wherein stub vanes 16 projecting from the inner wall towards the outer wall are combined with straightening vanes 18 projecting from the outer wall towards the inner, such that vortices generated by the vanes 16 are substantially cancelled by those generated by the vanes 18 and the chords of the vanes are placed at an angle to the direction of fluid flow through the passage. The vortices generated by the tips of the blades delay the separation of a boundary layer of fluid, and the blades are arranged to remove any swirl from the fluid discharged. In the arrangement shown the vanes 18 are equal in number to the vanes 16 and are spaced downstream therefrom with their axes aligned and at the same angle to the turbine fluid discharge; in a modification, the vanes in each set may be placed opposite the spaces between the vanes in the other set. In a further modification the two sets of vanes may be placed at the same position axially of the passage; a second pair of sets of vanes may be placed downstream from the first sets, the straightening vanes in the second set being longer than those in the first, and a third set of stub vanes only may be placed downstream from the second sets of vanes. The vanes are preferably substantially perpendicular to the inner wall 12 of the passage, and the circumferential spacing in each set is preferably equal to the chord of the blades. Conventional straightening vanes of straight or twisted profile may be used in conjunction with the vanes according to the invention.
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