http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Jintao Liu,Shuhong Liu,Yuekun Sun,Lei Jiao,Yulin Wu,Leqin Wang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.5
The transient power failure process of a prototype pump-turbine was studied numerically by three-dimensional (3-D) simulations. Fluid coupling and dynamic mesh (DM) method were used to calculate the rotational speed of the runner. Simulations were performed based on turbulence model. Specific transient characteristics, such as the flow rate, head, rotational speed, were analyzed. The pumpturbine had a minimum head and a maximum axial force when the flow rate was 0 during the transient process. Pressure fluctuations increased when the pump-turbine ran at pump braking mode. Reverse flow in the casing as well as stall phenomenon in the runner had a great effect on the change of head. Pressure in the runner was greatly reduced when the pump-turbine ran at pump braking mode. The computational method could be used to interpret the abnormal phenomenon by the analysis of flow mechanism during a transient process.
An Outlook on the Draft-Tube-Surge Study
Nishi, Michihiro,Liu, Shuhong Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.1
If large pressure fluctuation is observed in the draft tube of a Francis turbine at part-load operation, we have generally called it draft-tube-surge. As occurrence of this phenomenon seriously affects the limit of turbine operating range, extensive studies on the surge have been made since proposal of surge-frequency criterion given by Rheingans. According to the literature survey of related topics in recent IAHR symposiums on hydraulic machinery and systems, in which state-of-the-art contributions were mainly presented, a certain review of them may be desirable for an outlook on the future studies in this research field. Thus, in this review paper, the authors' previous attempts for the last three decades to challenge the following topics: a rational method for component test of a draft tube, nature of spiral vortex rope and its behavior in a draft tube and cavitation characteristics of pressure fluctuations, are introduced together with other related contributions, expecting that more useful and significant studies will be accomplished in the future.
A New Blade Profile for Bidirectional Flow Properly Applicable to a Two-stage Jet Fan
Nishi, Michihiro,Liu, Shuhong,Yoshida, Kouichi,Okamoto, Minoru,Nakayama, Hiroyasu Korean Society for Fluid machinery 2009 International journal of fluid machinery and syste Vol.2 No.4
A reversible axial flow fan called jet fan has been widely used for longitudinal ventilation in road tunnels to secure a safe and comfortable environment cost-effectively. As shifting the flow direction is usually made by only switching the rotational direction of an electric motor due to heavy duty, rotor blades having identical aerodynamic performance for bidirectional flow should be necessary. However, such aerodynamically desirable blades haven't been developed sufficiently, since most of the related studies have been done from the viewpoint of unidirectional flow. In the present paper, we demonstrate a method to profile the blade section suitable for bidirectional flow, which is validated by studying the aerodynamic performances of rotor blades of a two-stage jet fan experimentally and numerically.
An Outlook on the Draft-Tube-Surge Study
Michihiro Nishi,Shuhong Liu 한국유체기계학회 2013 International journal of fluid machinery and syste Vol.6 No.1
If large pressure fluctuation is observed in the draft tube of a Francis turbine at part-load operation, we have generally called it draft-tube-surge. As occurrence of this phenomenon seriously affects the limit of turbine operating range, extensive studies on the surge have been made since proposal of surge-frequency criterion given by Rheingans. According to the literature survey of related topics in recent IAHR symposiums on hydraulic machinery and systems, in which state-of-the-art contributions were mainly presented, a certain review of them may be desirable for an outlook on the future studies in this research field. Thus, in this review paper, the authors' previous attempts for the last three decades to challenge the following topics: a rational method for component test of a draft tube, nature of spiral vortex rope and its behavior in a draft tube and cavitation characteristics of pressure fluctuations, are introduced together with other related contributions, expecting that more useful and significant studies will be accomplished in the future.
Li, Changchun,Wang, Zhigang,Liu, Bang,Yang, Shulin,Zhu, Zhengmao,Fan, Bin,Yu, Mei,Zhao, Shuhong,Li, Kui Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.4
The genetic diversities and relationships of 10 Chinese indigenous pig breeds and three exotic pig breeds have been evaluated using 26 microsatellites recommended by the Food and Agriculture Organization & the International Society of Animal Genetics (FAO-ISAG). The allele frequencies, genetic heterozygosity (H) and polymorphism information content (PIC) have been calculated. The results showed that genetic diversity of Chinese indigenous pig breeds is higher than that of the introduced pig breeds. The clustering of 10 breeds is generally consistent with their geographical distribution.
Numerical analysis of flow in a Francis turbine on an equal critical cavitation coefficient line
Yulin Wu,Jintao Liu,Yuekun Sun,Shuhong Liu,Zhigang Zuo 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6
Numerical simulation and model test were applied to study the cavitation flow in Francis turbines. The SST k-ω turbulence model and the mixture model were used to simulate the cavitating flow in the Francis turbine. An equal critical cavitation coefficient line was calculated and the flow in the Francis turbine was analyzed. Simulation results show reasonable agreement with the experimental data. It is confirmed that these cavitation model and numerical method is a useful way to study the two-phase cavitation flow in Francis turbines. On the equal critical cavitation coefficient line, the energy loss in the turbine may be caused by the rotating of vortex rope in the draft tube or flow separation in the runner. The study of equal critical cavitation coefficient line can provide a basic guidance for industry practice.
Experimental Study on Internal Flow of a Mini Centrifugal Pump by PIV Measurement
Wu, Yulin,Yuan, Huijing,Shao, Jie,Liu, Shuhong Korean Society for Fluid machinery 2009 International journal of fluid machinery and syste Vol.2 No.2
The internal flow field in a centrifugal pump working at the several flow conditions has been measured by using the particle image velocimetry (PIV) technique with the laser induced fluorescence (LIF) particles and the refractive index matched (RIM) facilities. The impeller of the centrifugal pump has an outlet diameter in 100mm, and consists of six two-dimensional curvature backward swept blades of constant thickness. Measured results give reliable flow patterns in the pump. It is obvious that application of LIF particle and RIM are the key methods to obtain the right PIV measured results in pump internal flow.
Jeerasit Bumrungpetch,Andy Chit Tan,Shuhong Liu,Xianwu Luo,Qing-Yu Wu,Jian-Ping Yuan,Ming-Kui Zhang 한국유체기계학회 2014 International journal of fluid machinery and syste Vol.7 No.1
Computational fluid dynamics (CFD) and particle image velocimetry (PIV) are commonly used techniques to evaluate the flow characteristics in the development stage of blood pumps. CFD technique allows rapid change to pump parameters to optimize the pump performance without having to construct a costly prototype model. These techniques are used in the construction of a bi-ventricular assist device (BVAD) which combines the functions of LVAD and RVAD in a compact unit. The BVAD construction consists of two separate chambers with similar impellers, volutes, inlet and output sections. To achieve the required flow characteristics of an average flow rate of 5 l/min and different pressure heads (left – 100mmHg and right – 20mmHg), the impellers were set at different rotating speeds. From the CFD results, a six-blade impeller design was adopted for the development of the BVAD. It was also observed that the fluid can flow smoothly through the pump with minimum shear stress and area of stagnation which are related to haemolysis and thrombosis. Based on the compatible Reynolds number the flow through the model was calculated for the left and the right pumps. As it was not possible to have both the left and right chambers in the experimental model, the left and right pumps were tested separately.