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- 저자 : Xuelong Yang (검색결과 5 건)
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Yang, Xuelong,Long, Xinping,Kang, Yong,Xiao, Longzhou Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.3
To improve annular jet pump (AJP) performance, new ways named constant rate of velocity/pressure change method (CRVC/CRPC) were adopted to design its diffuser. The design formulas were derived according to the assumption of linear velocity/pressure variation in the diffuser. Based on the two-dimensional numerical simulations, the effect of the diffuser profile and the included angle on the pump performance and the internal flow details has been analyzed. The predicted results of the RNG k-epsilon turbulence model show a better agreement with the experiment data than that of the standard and the realizable k-epsilon turbulence models. The AJP with the CRPC diffuser produces a linear pressure increase in the CRPC diffuser as expected. The AJP with CRPC/CRVC diffuser has better performance when the diffuser included angle is greater or the diffuser length is shorter. Therefore, the AJP with CRPC/CRVC diffuser is suitable for applications requiring space limitation and weight restriction.
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Xuelong Yang,Xinping LONG,Yong Kang,Longzhou Xiao 한국유체기계학회 2013 International journal of fluid machinery and syste Vol.6 No.3
To improve annular jet pump (AJP) performance, new ways named constant rate of velocity/pressure change method (CRVC/CRPC) were adopted to design its diffuser. The design formulas were derived according to the assumption of linear velocity/pressure variation in the diffuser. Based on the two-dimensional numerical simulations, the effect of the diffuser profile and the included angle on the pump performance and the internal flow details has been analyzed. The predicted results of the RNG k-epsilon turbulence model show a better agreement with the experiment data than that of the standard and the realizable k-epsilon turbulence models. The AJP with the CRPC diffuser produces a linear pressure increase in the CRPC diffuser as expected. The AJP with CRPC/CRVC diffuser has better performance when the diffuser included angle is greater or the diffuser length is shorter. Therefore, the AJP with CRPC/CRVC diffuser is suitable for applications requiring space limitation and weight restriction.
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Study on Internal Flow Mechanism and Performance of Double-suction Annular Jet Pumps
Chenbing Zhu,Xuelong Yang,Jie Ge,Qiwei Zhou,Jiegang Mou 한국유체기계학회 2024 International journal of fluid machinery and syste Vol.17 No.1
This paper adopts the theory of jet energy transfer analysis and computational fluid dynamics (CFD) technology to improve annular jet pump (AJP). The nozzle of AJP is improved so that the annular nozzle is wrapped by the suction nozzles on both sides, which creates a double-suction annular jet pump (DAJP). The primary flow injected into suction chamber is surrounded by the secondary flow. The energy loss caused by direct contact of the primary flow with the wall is reduced. CFD was used to analyze the flow mechanism and performance in order to optimize its structure. Simulation results show that: the performance of the jet pump with a nozzle distance of 8mm from the wall is better than that of the other three DAJPs and the prototype pump. Its maximum efficiency can reach 51.77%. When the flow rate ratio is less than 0.4, the turbulent kinetic energy (TKE) is larger. It causes instability and irregular fluid motion, which ultimately leads to fluid energy loss and flow resistance increase. The smaller the flow ratio, the larger the backflow area in the suction chamber. The backflow area disappears when the flow ratio is greater than 0.4. The prototype pump only appears the backflow area near the axis of the suction chamber, while the DAJP also has a backflow area near the wall where the nozzle connects with the suction chamber
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System Control Methods for Energy Efficiency Improvement of Parallel Pump Systems: A Review
Chenchen Hua,Maosen Xu,Jiegang Mou,Junlei Wang,Peijian Zhou,Xuelong Yang 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.4
With the consistent pursuit of global countries for the goal of carbon neutrality, the urgency of energy saving and emission reduction is self-evident. Considering the critical proportion of pump consumption in the total energy consumption, improving its energy efficiency is significant to energy saving and emission reduction. Recently, many researches have aimed to improve parallel pump systems' energy efficiency. Due to the inflexibility of the existing parallel pump systems structure and the difficulty of equipment modification, the research methods mainly focus on improving the system control methods to enhance the system performance further. This paper introduces the latest research progress in modeling and control methods for parallel pump systems, firstly analyzing the energy consumption of existing parallel pump systems and proposing the possibility of energy saving in parallel pump systems. Then the system modeling and control methods are discussed in detail, comparing the traditional control methods with the emerging control optimization methods and discussing the parallel pump systems structure and monitoring. This review is expected to provide insights for future research on improving the performance of parallel pump systems.
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Numerical investigation on the recirculation in annular jet pumps
Longzhou Xiao,Xinping LONG,Xiaohong Li,Qinglong Zeng,Xuelong Yang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6
The flow within the annular jet pump (AJP), in some degree, resembles the annular wall jet developing in a pipe with great axial pressure gradient. In some working conditions, there exists the backflow near the centerline. However this differs from the case in a center jet pump (CJP) that the recirculation emerges near the inner wall of the throat. The recirculation in AJP affects a lot to its performance, especially when AJP is utilized to convey something alive, such as fish. This paper aims to numerically study the impact of two parameters, the flow ratio M and the area ratio A, on the location, size and formation of the recirculation in AJP. After being validated by the experimental results, the RNG k-ε turbulent model was adopted. It is found that: (1) As M increases, the width and height of the recirculation in AJP decreases, and the separation point of the recirculation shifts gradually far away from the nozzle exit while the reattachment point slightly moves; (2) As A becomes larger, the width and height of the recirculation enlarged, with M keeping constant; (3) For AJP with constant A, the recirculation emerges when M declines to a critical value, and the value varies linearly with A; (4) The Craya-Curtet number Ct and the momentum ratio J, which take A and M into whole consideration, are also feasible in describing the disappearance of the recirculation. However the critical value of Ct and J are different from that discovered in CJP. The critical Ct increases with decreasing A and the critical momentum ratio Jc experiences a linear relationship with A.
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