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| 1 | 多级离心泵内部流场数值模拟与节能技术研究显示文摘采用计算流体力学数值模拟Flunet 6.3.26分析软件,选取标准κ-ε湍流模型和SIMPLE算法模拟了D450-60×7型多级离心泵节能优化前后泵内流道三维湍流数值,并对比分析了采集实际工况运行数据。结果表明,优化后的多级离心泵叶轮和导叶内部流场分布更趋均匀合理、效率高、节约能源,与实际吻合,并验证了该软件的有效性,为改型优化提供了理论依据。 | 程云章 张伟国 骆宾海 吴文权 | 2010 | 水电能源科学2010，28，10： | 14 |
| 2 | Hydraulic design and pre-whirl regulation law of inlet guide vane for centrifugal pump显示文摘A new hydraulic design method of three-dimensional guide vane for centrifugal pump is proposed on the assumption that the fluid at the outlet of guide vane satisfies the uniform velocity moment condition.The geometry of blade is controlled by the distributed rule of blade angles along the meridional streamline which is described by a fourth-order polynomial.Experiment results demonstrate that the designed guide vane can overcome the drawback of two-dimensional guide vane,enlarge the high efficiency scope and improve the hydraulic performance of centrifugal pump on the off-design operation conditions.In comparison with the performance of the centrifugal pump without inlet guide vane,the peak value of efficiency can be enhanced by 2.13% after the three-dimensional guide vane was being installed.The three-dimensional entire flow field of the centrifugal pump with inlet guide vane is simulated,and the basic principle and mechanism of inlet guide vane pre-whirl regulation are analyzed.The validity of design method has been proved. | TAN Lei ,CAO ShuLiang&GUI ShaoBo State Key Laboratory of Hydroscience and Engineering,Department of Thermal Engineering,Tsinghua University,Beijing 100084,China | 2010 | Science China(Technological Sciences)2010，53，8： | 14 |
| 3 | The Change of the Inlet Geometry of a Centrifugal Compressor Stage and its Influence on the Compressor Performance显示文摘The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly. | WANG Leilei YANG Ce ZHAO Ben LAO Dazhong MA Chaochen LI Du | 2013 | Journal of Thermal Science2013，22，3： | 13 |
| 4 | Statistical Characteristics of Suction Pressure Signals for a Centrifugal Pumpunder Cavitating Conditions显示文摘Centrifugal pumps are often used in operating conditions where they can be susceptible to premature failure. The cavitation phenomenon is a common fault in centrifugal pumps and is associated with undesired effects. Among the numerous cavitation detection methods, the measurement of suction pressure fluctuation is one of the most used methods to detect or diagnose the degree of cavitation in a centrifugal pump. In this paper, a closed loop was established to investigate the pump cavitation phenomenon, the statistical parameters for PDF(Probability Density Function), Variance and RMS(Root Mean Square) were used to analyze the relationship between the cavitation performance and the suction pressure signals during the development of cavitation. It is found that the statistical parameters used in this research are able to capture critical cavitation condition and cavitation breakdown condition, whereas difficult for the detection of incipient cavitation in the pump. At part-load conditions, the pressure fluctuations at the impeller inlet show more complexity than the best efficiency point(BEP). Amplitude of PDF values of suction pressure increased steeply when the flow rate dropped to 40 m^3/h(the design flow rate was 60 m^3/h). One possible reason is that the flow structure in the impeller channel promotes an increase of the cavitation intensity when the flow rate is reduced to a certain degree. This shows that it is necessary to find the relationship between the cavitation instabilities and flow instabilities when centrifugal pumps operate under part-load flow rates. | LI Xiaojun YU Benxu JI Yucheng LU Jiaxin YUAN Shouqi | 2017 | Journal of Thermal Science2017，26，1： | 11 |
| 5 | A novel vibration modeling method for a rotating blade with breathing cracks显示文摘This paper proposes a vibration modeling method for a rotating blade with breathing cracks, considering the coupling of the centrifugal effects, the breathing effects and the crack effects. Firstly, considering the combined effects of the centrifugal stress and the bending stress, a crack breathing model for the rotating blade is proposed. Since the crack surface cannot provide the spanwise centrifugal tensile stress, an additional bending moment will be generated at the crack surface in the rotating state.Therefore, an additional bending moment caused by the centrifugal stress is then constructed. In addition, due to the discontinuity of the crack cross section, the additional stiffness caused by the centrifugal effects of the cracked blade will be smaller than that of the normal blade. Therefore, a correction coefficient of the centrifugal stiffness is built. Furthermore, based on the Lagrange equation and the assumed modal method, the vibration equation of the rotating blade with a breathing crack is established(RBC model), and a strategy is constructed for solving this vibration equation. Finally, taking the finite element model(FEM) as a reference, the vibration responses of the RBC model, the open crack model(OC) and the bilinear crack model(BC) are compared. The necessity of the RBC model is illustrated, and the accuracy of the RBC model is verified. The RBC model is a computationally efficient alternative to the finite element analysis for the rotating cracked blade. It can provide an important tool for the vibration modeling and the vibration analysis of the rotating shaft-disk-blade system with cracked blades. | XIE JingSong ZI YanYang ZHANG MingQuan LUO QinYuan | 2019 | Science China(Technological Sciences)2019，62，2： | 10 |
| 6 | EXPERIMENTAL STUDY ON HIGH-SPEED CENTRIFUGAL PUMPS WITH DIFFERENT IMPELLERS显示文摘The experimental study is carded out on high-speed centrifugal pumps with three different impellers. The ex-perimental results and analysis show that high-speed centrifugal pumps with a closed complex impeller can achieve thehighest efficiency and the lowest head coefficient followed by those with half-open impeller and open-impeller, and canobtain much easily stable head-capacity characrastic curve, while those with a half-open complex impeller can't. Thecharacteristic curve with a open impeller is almost constant horizontal line before dropping sharply. The results also showthat the axial clearance between pump casing and impeller can influence greatly on the performance of centrifugal pumps. | Zhu Zuchao Chen YingState Key Laboratory of Fluid Power Transmission and Control, Zhejiang University,Hangzhou 310027, ChinaHuang Dunhui Jin Qingming Cangnan Special Pumps Co.Ltd of Zhejiang Province | 2002 | Chinese Journal of Mechanical Engineering2002，15，4： | 10 |
| 7 | A study on centrifugal casting of high speed steel roll显示文摘High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast iron rolls is poor and the cost of high-quality PM hard alloy rolls is very high. By means of centrifugal casting, HSS rolls having excellent wear resistance have been manufactured. The hardness of the HSS roll is 6.5~67 HRC, the range of variation is smaller than 2 HRC and its impact toughness is 15 J/cm2. The wear rate of HSS rolls used in the pre-finishing stands of high-speed hot wire-rod rolling mill reaches 2.5×10-4mm per ton steel. Furthermore, the manufacturing cost of HSS rolls is significantly lower than that of PM hard alloy rolls; it is only 30 percent of that of PM hard alloy rolls. | ~*H. G. Fu~1, X.H. Zhang~2(1. Department of Mechanical engineering, Tsinghua University, Beijing 100084, P. R. China 2. Roll Made LTD. of Taiyuan Iron and Steel(Group)Company, Taiyuan 030003, Shanxi, P. R. China) | 2004 | China Foundry2004，1，S1： | 6 |
| 8 | A Review of Rotating Stall in Vaneless Diffuser of Centrifugal Compressor显示文摘At present, off-design centrifugal compressor suffers from great instabilities, such as rotating stall and surge, which lead to work failure, strong pressure fluctuations, and violent vibrations of the entire system. One cause of these instabilities is the rotating stall occurring in vaneless diffuser. In this review, recent researches on rotating stall of vaneless diffuser in centrifugal compressor are reviewed, and its inductive mechanism and characteristic description are emphatically introduced. In vaneless diffuser, the rotating stall starts up and fully develops under non-design conditions with the characteristic of increasing pressure fluctuation amplitude. The negative effects of rotating stall include reverse flow and vortex, both of which have significant effects on the instability of centrifugal compressors. Some improvement methods of rotating stall are also introduced, and a lot of examples are given. Finally, some suggestions and discussions are put forward for the future work. | ZHANG Lei HE Ruiyang WANG Songling ZHANG Qian | 2020 | Journal of Thermal Science2020，29，2： | 6 |
| 9 | Centrifugal model tests and numerical simulations for barrier dam break due to overtopping显示文摘The present study focuses on the breaching process and failure of barrier dams due to overtopping. In this work, a series of centrifugal model tests is presented to examine the failure mechanisms of landslide dams. Based on the experimental results, failure process and mechanism of barrier dam due to overtopping are analyzed and further verified by simulating the experimental overtopping failure process. The results indicate that the barrier dam will develop during the entire process of overtopping in the width direction, whereas the breach will cease to develop at an early stage in the depth direction because of the large particles that accumulate on the downstream slope. Moreover, headcut erosion can be clearly observed in the first two stages of overtopping, and coarsening on the downstream slope occurs in the last stage of overtopping. Thus, the bottom part of the barrier dam can survive after dam breaching and full dam failure becomes relatively rare for a barrier dam. Furthermore, the remaining breach would be smaller than that of a homogeneous cohesive dam under the same conditions. | ZHAO Tian-long CHEN Sheng-shui FU Chang-jing ZHONG Qi-ming | 2019 | Journal of Mountain Science2019，16，3： | 6 |
| 10 | STUDY ON FLOWS THROUGH CENTRIFUGAL PUMP IMPELLER BY TURBULENT SIMULATION显示文摘A finite volume numerical method is presented for simulating internal tur-bulent flows on the blade-to-blade surface through a centrifugal pump impeller, in which, a mesh in body-fitted coordinates is generated for the computation. In detail, the SIM-PLEC algorithm is utilized for solving governing equations of incompressible viscous/turbulent flows through the pump impeller. The K-ε turbulence model is adopted to describe the turbulent flow process. Some worthwhile simulated results are presented. | Dai, Jiang Wu, Yulin Cao, Shuliang | 1997 | Journal of Hydrodynamics1997，9，1： | 5 |
| 11 | Numerical Study of Pressure Pulsation of Centrifugal Pumps with the Compressible Mode显示文摘The compressible effect of water is often neglected in the simulation of hydraulic machinery. However, based on experimental and numerical study, it is found that the compressibility of water could influence the magnitude of the pressure pulsation at some frequency in the pump. Therefore, in order to investigate the influence of water compressibility, compressible model is established by using Tait equation. The internal flow of centrifugal pump under different conditions is calculated by this model. The calculated results are compared with the incompressible results, and it is indicated that the compressibility of water has little effect on the performance parameters. But it affects the amplitude of pressure fluctuations at some discrete frequency, especially at the outlet of impeller and volute tongue where significant jet-wake and rotor/stator interaction appears respectively. Meanwhile, water compressibility makes greater influence on the flow pulsation under off-design condition. Therefore, it is necessary to consider the compressibility of working medium in the numerical simulation of unsteady flow in centrifugal pumps, especially in area with strong unsteady flow and at off-design condition. | YANG Jun LIU Jun LIU Xiaohua XIE Tian | 2019 | Journal of Thermal Science2019，28，1： | 5 |
| 12 | Cavitation performance of high-speed centrifugal pump with annular jet and inducer at different temperatures and void fractions显示文摘The cavitation is very common in a centrifugal pump,especially when the speed is very high,and it seriously influences the centrifugal pump performance.In this investigation,the RNG k-ε turbulence model and the cavitation model with consideration of the mass transferring are first used to simulate the cavitation performance of the high-speed centrifugal pump without taking any measure for improving the pump cavitation performance.The calculation results reveal that a number of bubbles appear in the centrifugal pump flow channel,and the head as well as the flow rate of the high-speed centrifugal pump are far from its design condition.The cavitation performance can be improved effectively by arranging a variable pitch inducer and adopting an annular nozzle scheme.The flow field analysis of the pump is conducted to obtain the suitable working temperature distribution at different void fractions.On one hand,with the same void fraction,the head of the centrifugal pump drops slowly with the increase of temperature.However,when the temperature exceeds 90°C,the head of the pump drops rapidly.On the other hand,at the constant temperature,the higher the void fraction,the worse the cavitation performance.This research conducted under different temperatures and void fractions provides some guidance for designing an effective high-speed centrifugal pump. | Jin Jiang Yan-hui Li Chong-yan Pei Lin-lin Li You Fu Hong-gui Cheng Qiang-qiang Sun | 2019 | Journal of Hydrodynamics2019，31，1： | 5 |
| 13 | Cortical Organization of Centrifugal Afferents to the Olfactory Bulb: Mono-and Trans-synaptic Tracing with Recombinant Neurotropic Viral Tracers显示文摘Sensory processing is strongly modulated by different brain and behavioral states,and this is based on the top-down modulation.In the olfactory system,local neural circuits in the olfactory bulb(OB)are innervated by centrifugal afferents in order to regulate the processing of olfactory information in the OB under different behavioral states.The purpose of the present study was to explore the organization of neural networks in olfactory-related cortices and modulatory nuclei that give rise to direct and indirect innervations to the glomerular layer(GL)of the OB at the whole-brain scale.Injection of different recombinant attenuated neurotropic viruses into the GL showed that it received direct inputs from each layer in the OB,centrifugal inputs from the ipsilateralanterior olfactory nucleus(AON),anterior piriform cortex(Pir),and horizontal limb of diagonal band of Broca(HDB),and various indirect inputs from bilateral cortical neurons in the AON,Pir,amygdala,entorhinal cortex,hippocampus,HDB,dorsal raphe,median raphe and locus coeruleus.These results provide a circuitry basis that will help further understand the mechanism by which olfactory informationprocessing in the OB is regulated. | Pengjie Wen Xiaoping Rao Liuying Xu Zhijian Zhang Fan Jia Xiaobin He Fuqiang Xu | 2019 | Neuroscience Bulletin2019，35，4： | 4 |
| 14 | The Flow Simulation and Experimental Study of Low-Specific-Speed High-Speed Complex Centrifugal Impellers | 崔宝玲 朱祖超 张剑慈 陈鹰 | 2006 | Chinese Journal of Chemical Engineering2006，14，4X： | 4 |
| 15 | Unsteady flow structures in centrifugal pump under two types of stall conditions显示文摘The stall is an unsteady flow phenomenon that always causes instabilities and low efficiency for pumps. This paper focuses on the unsteady flow structures and evolutions under two types of stall conditions in centrifugal pump impellers. Two centrifugal pump impellers, one with 6 and another with 5 blades, are considered and a developed large-eddy simulation method is adopted. The results show that the alternative stall occurs in the impeller with 6 blades, while, the rotating stall is observed in that with 5 blades. The flow structure and the pressure fluctuation characteristics are further analyzed. For the alternative stall, the stall cells are fixed relative to the impeller, but a large vortex in the stalled passage is always swaying. The outlet vortex is generated from it, and then develops and sheds periodically. For the rotating stall, the stall cells first occur in the suction side of the blade. With the growth of the stall cells, the block area gradually increases until the inlet region is almost blocked, then moves to the pressure side with a continuous decay. When the rotating stall occurs, the amplitude of the pressure fluctuation is much larger than that under the alternative stall condition. The propagation of the stall cells has a significant effect on the pressure fluctuations in the impeller. | 周佩剑 戴嘉铖 李亚飞 陈婷 牟介刚 | 2018 | Journal of Hydrodynamics2018，30，6： | 4 |
| 16 | Influences of the diameter of the balance hole on the flow characteristics in the hub cavity of the centrifugal pump显示文摘The diameter of the impeller balance hole in a centrifugal pump is closely related to axial force.Thus,to select the appropriate diameter of a balance hole is crucial for balancing the axial force of the centrifugal pump.After the validation of the CFD method and the grids independence study,the characteristics of flow in the hub cavity have been analyzed in 4 cases with different diameters of balance holes.The leakage rate of the liquid in the hub cavity of the centrifugal pump is calculated and compared with the test result.According to the research,when no balance hole exists,the distribution of liquid velocity in the core area of the hub cavity exhibits axial symmetry,and the circumferential velocity component is approximately 0.4 times of the impeller's rotational speed.When the balance hole exists,the distribution of liquid velocity in the hub cavity does not exhibit axial symmetry,and the circumferential velocity component is larger than 0.4 times of the impeller's rotational speed.The radial leakage velocity on the turbulent boundary layer of the pump cover will increase with the increasing diameter of the balance hole. | Wei Dong Wu-li Chu Zai-lun Liu | 2019 | Journal of Hydrodynamics2019，31，5： | 4 |
| 17 | The Effect of Body Pitching on Leg-Spring Behavior in Quadruped Running显示文摘In this paper we investigated how the running speed would affect the dynamics of body pitching, and whether body inertiais important for animals. Passive trotting of spring-mass model and passive bounding of spring-beam model were studied atdifferent speeds for different sets of body parameters respectively. Furthermore, different body inertias were used in bounding.We found that running speed exerts effect on leg performance by means of centrifugal force. The centrifugal force can be understoodas an enhancement to the natural frequency of the spring-mass system. The disadvantage of body pitching may beoffset by the great increase in centrifugal force at high speed. The results also reveal that body mass distribution might not be themain reason for the difference in maximal running speeds of different animals. | Qi Deng, Shigang Wang, Qinghua Liang, Jinqiu Mo School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 P. R. China | 2010 | Journal of Bionic Engineering2010，7，3： | 4 |
| 18 | Experimental Analysis of the Rotor Stator Interaction Within a High Pressure Centrifugal Compressor显示文摘An analysis of the experimental results obtained by laser two focus anemometry in the rotor-stator inter-row region of a high-speed high-pressure centrifugal compressor is presented with the aim of quantifying the unsteady effects of the rotor-stator interaction. Two complementary methods are used. First, the results are analyzed in terms of the time-averaging procedure developed by Adamczyk. The purely time dependent correlations of the velocity components are quantified. They show that the unsteady interaction is mainly due to the splitter wake-vane interaction. Then, it is shown that the rotor-stator interaction produces spatial harmonics which are identified as spinning modes by means of Fourier series. | Isabelle Trébinjac Christophe Vixège | 2002 | Journal of Thermal Science2002，11，1： | 4 |
| 19 | THE PERTURBATION SOLUTIONS OF THE FLOW IN A ROTATING CURVED ANNULAR PIPE显示文摘WT5”BZ]In this paper, the flow in a rotating curved annular pipe is examined by a perturbation method. A second order perturbation solution is presented. The characteristics of the secondary flow and the axial flow are studied in detail. The study indicates that the loops of the secondary flow are more complex than those in a curved annular pipe without rotation and its numbers depend on the ratio of the Coriolis force to centrifugal force F. As F≈-1, the secondary flow has eight loops and its intensity reaches the minimum value, and the distribution of the axial flow is like that of the Poiseuille flow. The position of the maximum axial velocity is pushed to either outer bend or inner bend, which is also determined by F. [WT5”HZ] | Zhang Ben-zhao, Chen Qian, Zhang Jin-suo, Cui Liang-chen Department of Mechanics, Zhejiang University, Hangzhou, 310027, China | 2001 | Journal of Hydrodynamics2001，13，1： | 4 |
| 20 | Study on Unstable Characteristics of Centrifugal Pump under Different Cavitation Stages显示文摘In order to reveal the regularity of unsteady flow of centrifugal pump under different cavitation stages,a visual closed test-bed is built to collect signals such as the distribution of cavitation bubbles at the impeller inlet and external characteristics,etc.in the process of cavitation of centrifugal pumps.Combined with the shape and distribution of bubbles captured by high-speed photography,the cavitation stage of the centrifugal pump is divided.In addition,the variation of vorticity distribution,pressure pulsation and radial force of centrifugal pump under different cavitation stages are studied using the standard κ-ε turbulence model and the Kunz cavitation model.Main contributions are as follows:The cavitation bubbles can absorb the energy of vortex core to a certain extent and increase the volume of vortex core.Cavitation bubbles can also block the flow-path and induce the distortion of the internal flow field,resulting in unstable pressure waves that cause a significant increase in pressure pulsation rate.Besides,with the development of cavitation,the radial force on the impeller tends to remain invariable first and then decrease,and trajectory of the radial force changes from closed to open. | DONG Liang SHANG Huanhuan ZHAO Yuqi LIU Houlin DAI Cui WANG Ying | 2019 | Journal of Thermal Science2019，28，4： | 4 |
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