The Roto-Jet Pump Internal Flow Field Numerical Analysis And The Design Of The Collecting Pipe

The Roto-Jet pump is a new kind of very low specific speed pump, which has many characters, such as low flux, high pressure centrifugal pumps.The over-current components and structures and high-speed centrifugal pumps with differences Its efficiency is higher about 10-20% than the centrifugal pump which is the same specific speed. It is always used in the industry of oil, chemical, metallurgy, paper making, fire fighting. Because it is used relatively late in fastening the research of gushing out the pump at home, and is not deep enough and overall to study, especially of the pick-up tube and rotor cavity, it is still relatively low to cause the efficiency of this type pump. Besides that, there also is a terrible problem in the use of the Roto-jet pump, which is huge startup momentum. So the Roto-Jet pump is less to use. Therefore, it has very important theory value and well applicable foreground to research in the rule of the flow field inside and the startup characteristic of the Roto.Jet pump.The subjects used Fluent6.1 software, using the standard k-equation turbulence model and SIMPLEC algorithm, the XP300-3.type Roto-Jet pump internal flow field numerical simulation of the collecting pipe-type, the number of one and the laws of its inside,outside fluid flow have undertaken major research and analysis for the Roto-jet pump of the main conclusions are as follows:1)Through the numerical research in the internal rotor cavity's fluid flow regularity and a different axial length, circumferential cross.section analysis of the different calculations found that by analyzing the internal velocity field, pressure field and the turbulent kinetic energy comparing the distribution of the pros and cons of various models come to collecting pipe control and the appearance of the modified set of the original number of flow control hydraulic performance have a greater impact. Which come to the appearance of the modified in collecting pipe the number of it have a greater impact for hydraulic performance of flow control.2) Another part of the paper is researched and analyzed for the shape of collecting pipe's inlet and throat changes, as the collecting pipe in the rotor cavity is static, while the rotor cavity and impeller is consolidated together and run high.speed operation, because the flow is difficult to be measured experimental methods. By numerical simulation, the internal flow law has been in the collecting pipe and the rotor cavity, the internal speed and the pressure in the rotor cavity changes along the radius of linear in body. The change of the axial velocity is uniform and stable in addition to the collecting pipe's inlet in rotor cavity. 3)After analyzing the different conditions, the distribution of speed,pressure, turbulent kinetic energy, we can come to the conclusion:the liquid from the outlet of the impeller into the rotor cavity speed has a certain decline.the fluctuations be found in the small and big flow traffic conditions.while is a relatively stable flow of in only in the design condition,the static pressure changes largely in the impeller outlet and the collecting pipe inlet, so it is essential to choose a suitable condition for improving the pump performance.