| 摘要 |
Axial flow turbomachinery having an impeller with a plurality of contoured blades mounted within a diffuser throat and about a central rotatable hub. This blade shape is defined by the ratio of the blade root and tip chords to the minimum midsection blade chord, which is between about 1.25 and about 2.25. The ratio of blade pitch at the root and tip sections as compared with the blade midsection pitch is preferably between about 1.0 and about 1.4. This configuration of a preferred diffuser is described by the following relationship: <IMAGE> Where At is the diffuser cross-sectional area at the diffuser throat, Ao is the diffuser cross-sectional area at the outlet, l is the diffuser length from the diffuser throat to the diffuser outlet, x is a distance along the diffuser measured from the diffuser throat toward the diffuser outlet, Ax is the diffuser cross-sectional area x distance from the diffuser throat and n is a value between about 2 and about 4. The thruster diffuser or venturi throat may be provided with a curvilinear surface whose radius as compared with the throat radius is between about 0.2 and 1.0. In operation, the diffuser imparts an increased pressure head at the blade tip and root sections and may be reversably operated.
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