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泵站蝸殼式出水流道三維紊流數(shù)值模擬
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    摘要:

    采用RNG k-ε湍流模型閉合雷諾時均Navier-Stokes方程,數(shù)值模擬了某大型混流泵裝置中蝸殼式出水流道的內(nèi)部流動,在分析關(guān)鍵斷面流態(tài)的基礎(chǔ)上,對該出水流道的水力特性進行了預(yù)測。模擬結(jié)果表明,蝸殼式出水流道的內(nèi)部流態(tài)非常復(fù)雜,在一些區(qū)域有局部渦流和脫流現(xiàn)象,流速分布均勻性較差。蝸殼出口和流道出口斷面的軸向流速分布均勻度曲線均為開口向下的曲線,而出口水流偏流角曲線則是開口向上的曲線,對應(yīng)于水泵裝置最高效率點,兩者分別達到最大值和最小值。水頭損失隨流量變化而變化,在水泵裝置最高效率點達到極小值。水泵裝置在偏離設(shè)計工況大流量側(cè)運行時,出水流道的水頭損失迅速增加,裝置效率急劇下降。

    Abstract:

    The internal flow of a volute-type discharge passage in a mixed-low pumping system was numerically simulated with the RNG k-εturbulence model of the time-average closed Navier-Stokes equations and on the basis of analyzing the flow patterns in key cross sections, the hydraulic characteristics of the discharge passage was predicted. The computed results showed that the internal flow field is very complicated with flow separation and vortex in some regions, and the velocity distribution uniformity are quite poor. The uniformity curves of axial velocities discharge in the outlet cross-sections of the volute and the passage are protruding ones while the bias angle curves for the same cross-sections are concave ones, they would reach their maximums and minimums respectively at the discharge corresponding to the best efficiency point of the pumping system. When the pumping system operated under off-design conditions on the larger flow rate side, the head loss of the passage would increase rapidly to cause the efficiency of pumping system drop sharply.

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朱紅耕,袁壽其,劉厚林,施衛(wèi)東.泵站蝸殼式出水流道三維紊流數(shù)值模擬[J].農(nóng)業(yè)機械學(xué)報,2007,38(10):49-53.[J]. Transactions of the Chinese Society for Agricultural Machinery,2007,38(10):49-53.

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