CAJ | 학술논문

以一离心泵为对象，进行模型泵叶轮进口前非定常流动的PIV试验及数值模拟。基于PIV试验结果可知，在不同流量工况下，吸入管内均存在着较为强烈的预旋流动，预旋流的方向与叶轮旋转方向一致。且泵偏离设计流量工况越大、与叶轮距离越近，预旋流的绝对速度越大。同时，应用数值模拟的方法，详细分析了吸入管内部流场中涡线、压力脉动等的非定常变化，得出在小流量工况下，吸入管内非定常预旋流动将会引起与叶轮转频较为接近的压力脉动，从而对整个泵系统造成严重危害。
이일리심빙위대상，진행모형빙협륜진구전비정상류동적PIV시험급수치모의。기우PIV시험결과가지，재불동류량공황하，흡입관내균존재착교위강렬적예선류동，예선류적방향여협륜선전방향일치。차빙편리설계류량공황월대、여협륜거리월근，예선류적절대속도월대。동시，응용수치모의적방법，상세분석료흡입관내부류장중와선、압력맥동등적비정상변화，득출재소류량공황하，흡입관내비정상예선류동장회인기여협륜전빈교위접근적압력맥동，종이대정개빙계통조성엄중위해。
In this paper, the unsteady flow upstream of a model pump impeller has been investigated by both PIV experimental test and numerical simulation. From the PIV experimental test results, it is noted that the strong pre-swirl flow whose direction is the same as the impeller rotation exists in suction pipe at different flow rates. Further, the pre-swirl intensity becomes higher at smaller flow rates away from the design condition or where the distance is closer to the impeller. Also, the unsteady behavior of vortices lines and pressure fluctuations in the flow field of suction pipe was analyzed in detail based on the three dimensional numerical simulation. From numerical simulation results, it is noted that those pre-swirl flows in the suction pipe can induce pressure fluctuations at smaller flow rates conditions, whose dominant component having the equivalent frequency of impeller revolution, to threaten the safe operation of a pump.