农业装备技术
農業裝備技術
농업장비기술
Agricultural Equipment & Technology
2014年
2期
10-12,13
,共4页
离心泵%空化%非定常流动%可视化实验
離心泵%空化%非定常流動%可視化實驗
리심빙%공화%비정상류동%가시화실험
Centrifugal pumps%Cavitation%Unsteady cavitating flow%Visuable experiment
基于混合多相流模型，不同的湍流模型及完整空化模型，对比转数为86的离心泵内部流道的空化流动进行了定常和非定常的数值模拟，预测了空化初生阶段、发展阶段和空化严重阶段叶轮流道内空泡分布的形态特征。利用高速摄像机和设计的可视化离心泵，对空泡形态特征和连续时间内的叶轮内空化流场的观察与分析，获得了叶轮旋转过程中相邻叶片流道中非定常空化流动的变化规律。结果表明：拍摄所得空泡形态特征随NPSH的变化规律与数值计算结果基本一致，验证了数值计算的有效性；当某一叶片背面上或某一叶片流道内出现严重空化时，紧跟其后的叶片背面上或叶片流道内空化现象会受到抑制，但在其工作面上会出现明显的空化区。
基于混閤多相流模型，不同的湍流模型及完整空化模型，對比轉數為86的離心泵內部流道的空化流動進行瞭定常和非定常的數值模擬，預測瞭空化初生階段、髮展階段和空化嚴重階段葉輪流道內空泡分佈的形態特徵。利用高速攝像機和設計的可視化離心泵，對空泡形態特徵和連續時間內的葉輪內空化流場的觀察與分析，穫得瞭葉輪鏇轉過程中相鄰葉片流道中非定常空化流動的變化規律。結果錶明：拍攝所得空泡形態特徵隨NPSH的變化規律與數值計算結果基本一緻，驗證瞭數值計算的有效性；噹某一葉片揹麵上或某一葉片流道內齣現嚴重空化時，緊跟其後的葉片揹麵上或葉片流道內空化現象會受到抑製，但在其工作麵上會齣現明顯的空化區。
기우혼합다상류모형，불동적단류모형급완정공화모형，대비전수위86적리심빙내부류도적공화류동진행료정상화비정상적수치모의，예측료공화초생계단、발전계단화공화엄중계단협륜류도내공포분포적형태특정。이용고속섭상궤화설계적가시화리심빙，대공포형태특정화련속시간내적협륜내공화류장적관찰여분석，획득료협륜선전과정중상린협편류도중비정상공화류동적변화규률。결과표명：박섭소득공포형태특정수NPSH적변화규률여수치계산결과기본일치，험증료수치계산적유효성；당모일협편배면상혹모일협편류도내출현엄중공화시，긴근기후적협편배면상혹협편류도내공화현상회수도억제，단재기공작면상회출현명현적공화구。
Based on mixture model, full cavitaion model and various turbulence models,the steady and un-steady cavitating flow-passages in centrifugal pump with specific speed of 86 were numerically simulated. The morphological characteristics of cavitation at different stages were estimated.The cavitation morphologi-cal characteristics were catched through the high speed camera system and the visualization pump as well as the features and regularities of unsteady cavitating flow in adjacent blade passage.The simulation results in-dicate that the experiments results of the cavitation morphological characteristics which were observed are consistent with the simulation results proving its effectiveness.When a severe cavitation appears on the back of the blade or a blade runner, the cavitation of the next blade or passage will be suppressed, but cavitation zone will be appeared in the working surface.
