摘要
通过对南水北调工程等比例缩放模型泵进行全流道数值分析和试验研究,对模型泵在3个典型流量工况下的空化计算进行适应性研究,探究叶轮区域的空化发展特性,并对不同叶顶间隙δ(0.5,1.5和3.0mm)下的轴流泵空化特性进行对比分析,比较叶顶间隙大小对轴流泵空化性能和流场的影响.结果表明:随着空化数的降低,空化首先在叶片进口边间隙区附近发生,逐渐往叶片出口边扩大,同时沿径向往叶片背面扩大最终覆盖整个叶片,引起叶片出口靠近叶顶间隙10%区域的轴向速度逐渐降低;随着叶顶间隙的增大,模型泵的临界空化数增大,叶片轮缘处空化逐渐严重且由叶片前端往尾部移动,叶片出口轴向速度低速区主要集中在靠近间隙10%区域处,揭示了这一过程不同叶顶间隙轴流泵内部空化特性.
To carry out the adaptability study of cavitation calculation for the model pump under three typical flow conditions, the development characteristics of cavitation of impeller area was explored, and the axial flow pump cavitation characteristics under different tip clearance 8 （0.50, 1.50 and 3.00 mm） were comparative analyzed. The effects on cavitation characteristics and flow field of axial flow pump for the value of tip clearance were compared through making the numerical analysis and experi- mental study of full passage using scaling the model pump of south-to-north water transfer project for equal ration. The results show that the cavitation occurs at the blade inlet edge close to the tip clear- ance firstly with the reduction of cavitation number σ, and expands gradually to the outlet edge of blade, meanwhile to the suction surface of blade along radial direction and eventually occupies the en- tire suction surface of blade, causing the axial velocities of blade outlet edge close to 10% area of tip clearance decrease gradually. The critical cavitation number of model pump increases with the increase of tip clearance. The cavitation damage of cylindrical section of blade rim becomes serious gradually and moves from the front to the tail of blade with the increase of tip clearance, and the low velocity ar- eas of axial velocity for blade outlet are mainly concentrated in the region of blade near 10% clearance. This process reveals the interior cavitation characteristics of axial flow pump with different tip clear- ance.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第4期21-25,共5页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51079063
51109093)
江苏省自然科学基金资助项目(BK2011503)
江苏省科技成果转化专项资助项目(BA2011126)
江苏省高校优势学科建设工程资助项目(PAPD)
关键词
轴流泵
间隙空化
叶顶间隙
流场结构
空化特性
数值模拟
axial-flow pump
leakage cavitation
tip leakage
flow field structure
cavitation charac-tersitic
numerical simulation
