| 液力涡轮制动停机瞬态过程的数值模拟 |
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| 引用本文： | 焦磊;张鹏鹏;刘锦涛;尹俊连;王乐勤.液力涡轮制动停机瞬态过程的数值模拟[J].排灌机械,2013(11):969-972,1006. |
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| 作者姓名： | 焦磊;张鹏鹏;刘锦涛;尹俊连;王乐勤 |
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| 作者单位： | 浙江大学化工机械研究所 |
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| 基金项目： | 国家自然科学基金资助项目(51006087) |
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| 摘 要： | 为研究液力刹车制动系统液力涡轮在停机过程中的制动性能,建立液力涡轮三维CFD计算模型,合理设置边界条件,利用SST k-ω湍流模型模拟其制动过程.分别采用准稳态计算方法和瞬态计算方法对液力涡轮的制动过程进行模拟计算,根据计算结果对液力涡轮制动过程中有代表性意义的不同工况点进行研究,并对比准稳态计算方法与瞬态计算方法模拟出的液力涡轮性能的异同.模拟计算结果表明,在液力涡轮制动初始阶段,准稳态计算与瞬态计算结果基本相似,流动无明显的回流涡结构,但制动力矩差别较大;瞬态计算方法结果表明,当转速降低至2 000 r/min后,叶轮出现了失速现象,随着转速的降低失速越来越明显,低转速下流线呈不规则状;失速发生前,瞬态计算的转轮内部压力明显高于准稳态结果,说明转轮中的能量损失大于准稳态计算结果.
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| 关 键 词： | 液力涡轮 制动过程 准稳态模拟 瞬态模拟 失速现象 |
Numerical simulation of braking transient process for hydraulic turbine |
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| Institution: | Jiao Lei;Zhang Pengpeng;Liu Jintao;Yin Junlian;Wang Leqin;Institute of Process Equipment,Zhejiang University; |
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| Abstract: | In order to study the braking performance of hydraulic turbine in a hydraulic braking system in shut-down process,a CFD computational model of a hydraulic turbine was established,and the SST k-ω turbulence model was used to simulate the process. The different operating points in the braking process were selected and the process was simulated by the quasi-steady and transient computational methods,respectively;then the various CFD results were compared. The results showed that the streamlines in blade to blade surfaces obtained by the two methods are similar basically,and there is no noted reverse flow structure,but the braking torque is quite different between both methods in the initial phase of braking process. For the transient method,however,a stall phenomenon appears when the turbine operating speed is reduced to below 2 000 r / min;further,with decreasing speed,the stall becomes more and more dominated. Importantly,the static pressure in the turbine obtained with the transient method is significantly higher than that with the quasi-steady one,suggesting the hydraulic losses in the turbine given by the former method are larger than those by the latter. |
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| Keywords: | hydraulic turbine braking process quasi-steady state simulation transient simulation stall phenomenon |
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