张德胜,石磊,陈健,耿琳琳,刘俊龙.基于DCMFBM模型的轴流泵叶顶区云状空化脱落预测[J].农业机械学报,2016,47(8):22-28.
Zhang Desheng,Shi Lei,Chen Jian,Geng Linlin,Liu Junlong.Prediction of Cloud Cavitation Shedding in Tip Region of Axial Flow Pump Based on DCMFBM Turbulence Model[J].Transactions of the Chinese Society for Agricultural Machinery,2016,47(8):22-28.
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基于DCMFBM模型的轴流泵叶顶区云状空化脱落预测   [下载全文]
Prediction of Cloud Cavitation Shedding in Tip Region of Axial Flow Pump Based on DCMFBM Turbulence Model   [Download Pdf][in English]
投稿时间:2015-08-21  
DOI:10.6041/j.issn.1000-1298.2016.08.004
中文关键词:  轴流泵  云状空化  非定常脱落  DCMFBM湍流模型  高速摄影
基金项目:国家自然科学基金项目(51479083)、江苏省优势学科建设工程项目、江苏省产学研前瞻性联合研究项目(BY2015064-08)和江苏省重点研发计划项目(BE2015001-3)
作者单位
张德胜 江苏大学 
石磊 江苏大学 
陈健 江苏大学 
耿琳琳 江苏大学 
刘俊龙 江苏大学 
中文摘要:为了深入研究轴流泵叶顶区云状空化非定常脱落过程,应用二次开发技术将基于密度修正的RNG k-ε湍流模型的滤波器模型(Density correction method filter based model, DCMFBM))嵌入商业软件ANSYS CFX中进行数值模拟,并将模拟的结果与高速摄影试验作对比。数值模拟结果表明,DCMFBM模型能够成功地预测叶顶区云状空化尾缘空穴的周期性脱落过程,与试验值吻合较好。随着叶片的转动,脱落的空穴向相邻叶片的压力面运动,运动过程中的破裂消失不仅影响了相邻叶片压力面载荷分布,同时会影响自身叶片吸力面载荷分布;由于轮毂与叶片的相互作用,形成了从轮毂到轮缘的径向射流,径向射流在运动到靠近叶顶区时,会冲击叶顶区空穴表面,造成叶顶区空穴的脱落,同时径向射流最终被叶顶泄漏涡吸收。
Zhang Desheng  Shi Lei  Chen Jian  Geng Linlin  Liu Junlong
Jiangsu University,Jiangsu University,Jiangsu University,Jiangsu University and Jiangsu University
Key Words:axial-flow pump  cloud cavitation  unsteady shedding  DCMFBM turbulence model  high speed photography
Abstract:A type of cavitation pattern named triangle cloud cavitation structure, which was formed by tip clearance cavitation, shear layer cavitation and tip leakage vortex cavitation, would cause some adverse effects on its shedding cavity at the trailing edge, such as diminished overall performance and efficiency, rotating instabilities, noise and vibration. Thus the mechanism of the phenomenon should be understood. For the sake of deeply studying the process of cloud cavitation shedding in the tip region of an axial-flow model pump, the filter-based model with modified density of RNG k-ε turbulence model was embedded into the commercial software ANSYS CFX by the secondary development technology for simulation. Simultaneously, the homogenous cavitation model was also adopted to simulate the unsteady cavitating turbulent flows. Some significant results were summarized. The simulation results were compared with experimental values. It could be concluded that the simulation results were agreed well with experimental values by successfully predicting the periodic process of cloud cavitation shedding in the tip region with DCMFBM turbulence model. With the rotation of blade, the shedding cavity was migrated towards the pressure side of neighboring blade and affected the load distribution of the pressure side;meanwhile, it also had impact on its load distribution on the suction side. A radial jet from the hub to the rim was found near the exit of blade, when it reached the blade tip, it eventually impinged on the cavity surface near the wall, which caused the formation of an open cavity with shed bubbly clouds. Then it was entrained into the TLV, forming an unstable and noisy spiraling pattern, which would enhance the instabilities of the flow field in tip region. It was possible that hub vortices characterizing wing-body junctions might have also played a role.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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