摘要
针对不合适的离心泵叶片数会降低其输送流体效率,导致离心泵性能难以提升的问题,研究了叶片数对于离心泵内流动能量损失的影响。首先,采用UG建立了叶片数为4、5、6的离心泵流体域模型,并对各叶片数的离心泵流体域进行了六面体结构化网格划分;然后,采用ANSYS Fluent进行了数值模拟,研究了各叶片数的离心泵在0.6~1.4倍额定流量下的扬程、效率以及轴功率;采用熵产理论研究了不同叶片数在各流量下直接熵产(EGDD)、湍流熵产(EGTD)和壁面熵产(EGWS)的值与占比;最后,研究了进口域、出口域、叶轮域以及蜗壳域的熵产值(EGV)情况,还研究了熵产率(EGR)的空间位置分布。研究结果表明:叶片数越多,泵的扬程、效率与轴功率越大;额定流量下熵产值最低;叶轮域熵产值占最大比例,蜗壳域次之;黏性尾流区域熵产率较大,叶片压力面尾缘处的壁面熵产率最高。
Aiming at the problem that improper number of blades of centrifugal pump will reduce the efficiency of fluid delivery and make the performance of centrifugal pump difficult to improve,the influence of blade number on the flow energy loss in centrifugal pump was studied.Firstly,the fluid domain model of centrifugal pump with 4,5 and 6 blades was established by UG,and the fluid domain of centrifugal pump with each blade number was divided into hexahedral structured grids.Then,ANSYS Fluent was used to compute the head,efficiency and shaft power of the centrifugal pump with different blade numbers under the flow rate of 0.6~1.4 times of the rated flow.The entropy generation theory was used to study the values and proportion of entropy generation caused by direct dissipation(EGDD),entropy generation caused by turbulence dissipation(EGTD) and entropy generation caused by wall shear stress(EGWS) for different blade numbers at different flow rates.Finally,the entropy generation value(EGV) of the inlet,outlet,impeller and volute domains were studied,and the spatial distribution of the entropy generation rate(EGR) was also studied.The results show that the more the number of blades is,the larger the pump head,efficiency and shaft power are.The entropy generation value at rated flow is the lowest.The entropy generation value of impeller domain accounts for the largest proportion,followed by that of volute domain.The entropy generation rate in the viscous wake region is large,and the entropy generation caused by wall shear stress at the trailing edge of the blade pressure surface is the highest.
作者
苏永红
尹久
张杰
SU Yonghong;YIN Jiu;ZHANG Jie(College of Science,Engineering and Agricultural Medicine,Shanxi Open University,Taiyuan 030024,China;School of Mechanical and Electrical Engineering,Hubei Light Industry Technology Institute,Wuhan 430070,China;School of Mechanical and Electrical Engineering,Wuhan University of Technology,Wuhan 430070,China)
出处
《机电工程》
CAS
北大核心
2024年第6期1050-1057,1094,共9页
Journal of Mechanical & Electrical Engineering
基金
国家自然科学基金资助项目(51577065)。
关键词
离心泵
熵产理论
直接熵产
湍流熵产
壁面熵产
熵产值
熵产率
centrifugal pump
entropy production theory
entropy generation caused by direct dissipation(EGDD)
entropy generation caused by turbulence dissipation(EGTD)
entropy generation caused by wall shear stress(EGWS)
entropy generation value(EGV)
entropy generation rate(EGR)
