孔板消能问题数值研究  

Numerical research on orifice energy dissipation

作　　者：何宁[1,2,3] 赵振兴[1,2] 

机构地区：[1]河海大学浅水湖泊综合治理与资源开发教育部重点实验室,南京210098 [2]河海大学环境科学与工程学院,南京210098 [3]高能物理研究所实验物理中心,北京100049

出　　处：《水动力学研究与进展（A辑）》2009年第3期358-363,共6页Chinese Journal of Hydrodynamics

摘　　要：孔板消能是一种新型的内消能方式,其消能机制仍需进一步研究。已有的定性研究表明消能系数K的主要影响因素为:雷诺数Re、孔径比d/D和孔距比L/D。运用标准k-ε模型进行数值模拟定量研究各影响因素的作用发现:对于不同孔径比的模型,当Re<105时,K随Re增加而急剧增加;而当Re>105时,流动可视为充分发展的紊流,K渐趋于稳定;孔径比越小,消能系数K和漩涡区长度L1越大,且变化函数关系可视为直线分布;当孔距比L/D<5时,总消能系数随孔板间距离增加而显著增加,而当孔距比L/D>5时,总消能系数趋于稳定,L对K的影响可以忽略。使用孔板在管道内产生突扩水流,可以在较短的时间和距离内消除较多的能量。Orifice energy dissipater is a new energy dissipation method. Its mechanism has not been fully understood yet. On the basis of the former studies, the main factors that influence K are identified as Reynolds number, Re, and the ratio of d/D, and the ratio of L/D. Numerical simulations were conducted with a k-ε two-equation turbulence model. The calculated results can be identified as follows： For different ratio of d/D, when Re is smaller than 105, the orifice energy dissipater coefficient K increases rapidly with the increase of Re. When Re is larger than 105, the flow can be considered as full turbulent flow and K is gradually stable. The smaller of d/D, the larger of Zl and K. The function curve shape which can be approximated as a straight line. If L/D is smaller than 5, the total K increases rapidly with the L/D increasing; while when L/D is larger than 5, the total K becomes stable gradually. L almost has no impact on the value of K. Using sharp-edged orifice to generate sudden-enlarge ments in tunnel flow, large amount of energy can be dissipated in a short time and a small distance.

关 键 词：孔板消能 k-ε紊流模型雷诺数 孔径比 孔距比 

分 类 号：TV131.4[水利工程—水力学及河流动力学]