The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annu...The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annular volutes are available, and there is no systematic design method for annular volutes. In this study, the influence of volute casing cross-sectional flow area on the hydraulic loss, pressure pulsations, and radial force under varying working conditions in a centrifugal ceramic pump are discussed in detail. Experimental tests were conducted to validate the numerical results. The results indicated that, when the volute casing flow area increases, the hydraulic performance decreases marginally under the rated working conditions, but increases at the o-design points, specifically under large flow condition. However, the volute casing with a larger flow area has a wider high-e ciency region. In addition, the increase in the volute casing flow area will decrease the pressure pulsations in the volute, regardless of the working condition, and decrease the radial force on the shaft, therefore, providing an improved pump operational stability. It is anticipated that this study will be of benefit during the design of annular volutes.展开更多
In this paper we use the Green function method to solve the problem of steady one dimensional flow of an incompressible viscous, electrically conducting fluid through a pipe with partial circular ring cross sec- tion ...In this paper we use the Green function method to solve the problem of steady one dimensional flow of an incompressible viscous, electrically conducting fluid through a pipe with partial circular ring cross sec- tion and one with annular cross section, in the presence of an applied transverse uniform magnetic field, We ob- tain analytic solutions and carry out some numerical calculations of the velocity distribution and induced magnet- ic field.展开更多
目的：探讨子宫下段横形环状压迫缝合术（transverse annular compression sutures in the lower segment of uterine,TACS）在防治中央性前置胎盘剖宫产产后出血中的作用。方法：回顾性分析皖南医学院附属弋矶山医院2014年6月~2015年1...目的：探讨子宫下段横形环状压迫缝合术（transverse annular compression sutures in the lower segment of uterine,TACS）在防治中央性前置胎盘剖宫产产后出血中的作用。方法：回顾性分析皖南医学院附属弋矶山医院2014年6月~2015年1月应用TACS治疗的20例中央性前置胎盘患者产后出血的疗效及远期影响。结果：本组20例中央性前置胎盘剖宫产的患者经过TACS治疗,术中、术后出血均得到了有效的控制,无一例切除子宫;且术后恢复良好,均无相关并发症的发生。结论：TACS用于治疗中央性前置胎盘子宫下段出血,操作安全、快速、有效,值得在临床上广泛应用。展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51779107)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20170548)+1 种基金Postdoctoral Science Foundation of China(Grant No.2017M611724)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annular volutes are available, and there is no systematic design method for annular volutes. In this study, the influence of volute casing cross-sectional flow area on the hydraulic loss, pressure pulsations, and radial force under varying working conditions in a centrifugal ceramic pump are discussed in detail. Experimental tests were conducted to validate the numerical results. The results indicated that, when the volute casing flow area increases, the hydraulic performance decreases marginally under the rated working conditions, but increases at the o-design points, specifically under large flow condition. However, the volute casing with a larger flow area has a wider high-e ciency region. In addition, the increase in the volute casing flow area will decrease the pressure pulsations in the volute, regardless of the working condition, and decrease the radial force on the shaft, therefore, providing an improved pump operational stability. It is anticipated that this study will be of benefit during the design of annular volutes.
文摘In this paper we use the Green function method to solve the problem of steady one dimensional flow of an incompressible viscous, electrically conducting fluid through a pipe with partial circular ring cross sec- tion and one with annular cross section, in the presence of an applied transverse uniform magnetic field, We ob- tain analytic solutions and carry out some numerical calculations of the velocity distribution and induced magnet- ic field.
文摘目的：探讨子宫下段横形环状压迫缝合术（transverse annular compression sutures in the lower segment of uterine,TACS）在防治中央性前置胎盘剖宫产产后出血中的作用。方法：回顾性分析皖南医学院附属弋矶山医院2014年6月~2015年1月应用TACS治疗的20例中央性前置胎盘患者产后出血的疗效及远期影响。结果：本组20例中央性前置胎盘剖宫产的患者经过TACS治疗,术中、术后出血均得到了有效的控制,无一例切除子宫;且术后恢复良好,均无相关并发症的发生。结论：TACS用于治疗中央性前置胎盘子宫下段出血,操作安全、快速、有效,值得在临床上广泛应用。
