Cavitation Surge in a Small Model Test Facility Simulating a Hydraulic Power Plant
Cavitation Surge in a Small Model Test Facility Simulating a Hydraulic Power Plant
复制标题
DOI：
10.5293/ijfms.2012.5.4.152
复制
发表时间：
2012-12
影响因子：
--
通讯作者：
K. Yonezawa;D. Konishi;K. Miyagawa;F. Avellan;P. Doerfler;Y. Tsujimoto
中科院分区：
文献类型：
--
作者：
K. Yonezawa;D. Konishi;K. Miyagawa;F. Avellan;P. Doerfler;Y. Tsujimoto
为查明水电站汽蚀喘振的原因，进行了模型试验和计算流体动力学分析。在实验中，在有和没有调压室的情况下，在入口蜗壳的上游观察到了流量下的空化喘振。小流量时的喘振频率远小于涡带旋转引起的旋涡模态频率。在两种边界条件下进行了非定常CFD：（1）蜗壳进口处的流量固定为常数，（2）蜗壳进口处的总压力保持恒定，对应于无/有调压室的实验。在较高和较低流速下的两种边界条件下均观察到喘振。根据在扩压器出口处设置孔板和将扩压器更换为直管的附加试验，对喘振原因进行了讨论。
Model tests and CFD were carried out to find out the cause of cavitation surge in hydraulic power plants. In experiments the cavitation surge was observed at flow rate, both with and without a surge tank placed just upstream of the inlet volute. The surge frequency at smaller flow rate was much smaller than the swirl mode frequency caused by the whirl of vortex rope. An unsteady CFD was carried out with two boundary conditions: (1) the flow rate is fixed to be constant at the volute inlet, (2) the total pressure is kept constant at the volute inlet, corresponding to the experiments without/with the surge tank. The surge was observed with both boundary conditions at both higher and lower flow rates. Discussions as to the cause of the surge are made based on additional tests with an orifice at the diffuser exit, and with the diffuser replaced with a straight pipe.