[an error occurred while processing this directive]
排灌机械工程学报
   Home  About Journal  Editorial Board  Instructions for Authors    中文 
 
　

Office Online

 　
　  Author Center
　  Peer Review
　  Editor Work
　  Office Work
　  Editor-in-chief
　

Journal Online

 　
　  Forthcoming Articles
　  Current Issue
　  Next Issue
　  Archive
　  Read Articles
　  Download Articles
　  Email Alert
　  
Quick Search  
  Advanced Search
Journal of Drainage and Irrigation Machinery Engin
 
2013 Vol.31 Issue.10
Published 2013-10-25
article
Article
829 3D numerical simulation of internal flow in NTB multi-stage ceramic pump
Yuan Shouqi, Tao Yi, Cao Weidong, Tang Yue, Tao Jianping
The 3D modeling and grid meshing of the NTB multi-stage ceramic pump were achieved referring to the CAD hydraulic design. Based on the Reynolds Time-Averaged N-S equations with the standard k-ε turbulence model in the multiple reference frame, the internal flow in the multi-stage ceramic pump under nine different working conditions including design point were simulated by using CFX software. The static pressure contours, velocity vectors and streamlines were obtained. The principles of the internal flow under large flow rates, small flow rates and design condition were qualitatively analyzed, meanwhile, the performance curves of the pump were drawn. The simulation results show that the distribution of absolute velocity vector under design working condition is reasonable. No backflow is found in the outlet of the volute. The velocity in the outlet of reverse diffuser changes little and the velocity vector is uniform, but axial vortex occurs there. The streamlines in the middle sections of both impellers are asymmetric. There are different scales of jet-wake structures in the first-stage impeller under three working conditions and axial vortex is found under small flow rate conditions. Based on the simulation, the model of the NTB multi-stage ceramic pump was manufactured, and the hydraulic characteristics were tested. The results of simulation and experiment were compared.The computational and experimental results present good agreement and the model pump satisfies the design requirements which show that the NTB multi-stage ceramic pump is successfully developed. Meanwhile, the results of simulation can provide foundation for optimization design.
2013 Vol. 31 (10): 829-834 [Abstract] ( 1606 ) [HTML 1KB] [ PDF 3602KB] ( 1911 )
835 Prediction and numerical analysis for pressure fluctuation of axial-flow pump
Tang Fangping, Zhang Liping, Fu Jianguo, Xie Rongsheng, Yang Ning, Qi Lilong
Based on RANS equation and RNG k-ε model,Ansys-CFX software was adopted to simulate the 3D unsteady flow of an axial-flow pump sector under different working conditions.The pressure fluctuation value at different monitoring points in the axial-flow pump under different working conditions was obtained, the change trends were analyzed and the influence scope of the pressure fluctuation caused by impeller rotation was evaluated.Compared with the head and efficiency measured,the numerical simulation method was proved feasible and reliable.The results show that the pressure fluctuation frequency in the axial-flow pump is mainly dominated by the impeller rotation frequency, and the larger pressure fluctuation occurs at the impeller inlet. The pressure fluctuation at the impeller inlet increases from hub to shroud gradually and at the impeller outlet decreases first and then increases. However, the fluctuation at the guide vane outlet increases first and then decreases.The pressure fluctuations under the conditions of small flow and large flow are greater than that of the optimal condition.Because of the impeller rotation,the pressure fluctuation affects to 0.7D of the impeller in front of the inlet.
2013 Vol. 31 (10): 835-840 [Abstract] ( 1548 ) [HTML 1KB] [ PDF 3583KB] ( 1767 )
841 Analysis of ring deformation of hot-water pump based on thermo-solid coupling
Cao Weidong, Wang Xiulan, Hu Qixiang
The rotor parts wear were usually caused during the hot-water pump running process. In order to improve the reliability and safety of the pump, based on the software ANSYS Workbench, the TEG200-400 hot-water pump was analyzed with thermal-solid coupling at different temperatures. The ring deformations at different temperatures has been obtained, and the deformations were also analyzed with and without the cooling water chamber. The results can provide a certain basis for the choice of gap between the impeller ring and volute ring. The analysis shows that the flushing of the cooling water chamber affects the impeller ring deformation obviously, and during the running process of the high-temperature process pump, the temperature at the connection between pump cover and bracket should be decreased as much as possible to reduce the deformation of the impeller ring. The deformation of the volute ring and the impeller ring become greater as the media′s temperature increases. In order to avoid the friction between the volute ring and the impeller ring during the pump start and running process, the thermal deformation should be reasonably estimated, and the ring gap should be chosen for the design according to the temperature of the running medium, the pump structure, material cha-racteristics, et al. If the radius gap between impeller ring and volute ring is larger than 0.6 mm, the scheme is safe under the condition that media′s temperature is 250 ℃.
2013 Vol. 31 (10): 841-845 [Abstract] ( 1482 ) [HTML 1KB] [ PDF 2222KB] ( 1635 )
846 Numerical simulation of solid-liquid two-phase turbulent flow in centrifugal pump based on Particle model
Wang Jiaqiong, Jiang Wanming, Kong Fanyu, Qu Xiaoyun, Su Xianghui
3D simulation was performed for the solid-liquid two-phase turbulent flow in centrifugal pumps using particle model and inhomogeneous model separately by ANSYS-CFX software. The k-ε turbulence model was applied to predict the liquid-phase, while an algebraic equation known as the dispersed phase zero equation was adopted to predict the solid-phase. At wall boundaries, for the so-lid-phase the free slip wall conditions was used for mass and momentum. The slip velocity and the fraction volume of solid particles on the wall of flow-passage parts were studied. The computational results were compared with the results of the corresponding literature. It is found that solid particles mainly accumulated near the wall of the exit of volute. There are three places where slip velocity of solid particles is relatively high and erosion of walls is more serious. Such as the head of blade near front shroud and the blade trailing edge, also the shroud part close to the back pressure side of blade. With these two models respectively, the CFD simulation can accurately simulate solid-liquid two-phase turbulent flow.
2013 Vol. 31 (10): 846-850 [Abstract] ( 2743 ) [HTML 1KB] [ PDF 2755KB] ( 2543 )
851 Head degradation mechanism research on mixed-flow pump under cavitation conditions
Shi Wei,, Zhang Daqing, Pan Zhongyong, Li Yanjun, Yuan Shouqi
The cavitating flow in a mixed-flow pump with volute collector(the specific speed ns=449)under design condition was simulated numerically based on the cavitation model Rayleigh-Plesset equations and the SST turbulence model. The NPSHA-H curve was obtained accordingly.To investigate the inherence of mixed-flow pump cavitation breakdown condition and head degradation, the cavitation phenomenon in the impeller were comparatively analyzed under the inception,critical and severe cavitation conditions.The numerical simulation results and experimental ones were consistent with the error less than 5%. When the cavitation bubble in the flow passage adds up to a certain extent, it will make the liquid boundary layer separation and produce vortexes, which can be observed from the picture of vapor volume fraction distribution in impeller passage and streamline distribution on blade suction side. Vortex is the main cause of the mixed-flow pump cavitation breakdown and head degradation. The regularities of distribution of mixed-flow pump cavitating flow field were revealed.
2013 Vol. 31 (10): 851-855 [Abstract] ( 1747 ) [HTML 1KB] [ PDF 6563KB] ( 2076 )
856 Numerical simulation on running characteristics of low head pit turbine
Zhou Daqing, Chen Shifan, Li Chao
Through the establishment of unsteady state process of three-dimensional turbulence numerical simulation, operation characteristics of a new low head pit turbine without governor device were simulated under both the constant and varied runner rotation speed conditions while the inlet pressure was changing periodically. The numerical results show that, with 14% changing of the inlet pressure, the rotation speed change is up to 0.76% and down to 0.21% and the rotation speed fluctuation is 0.25 cycle delayed than that of the inlet pressure. In addition, the flow rate change is up to 8% and 2.5% at the peak value, as well as the efficiency change is down to 10.76% and up to 4%. The va-riation law of turbine torque, flow rate, power and efficiency with time was revealed, and in the variation process of the runner, the transient performance of runner flow in both conditions was analyzed,which can provide rational basis and suggestions for the electrical control equipment selection of a po-wer station.
2013 Vol. 31 (10): 856-861 [Abstract] ( 1425 ) [HTML 1KB] [ PDF 2354KB] ( 1936 )
862 Stress analysis of Francis hydraulic turbine runner based on FSI
Xiao Ruofu, Zhu Wenruo, Yang Wei, Liu Jie, Wang Fujun
To carry out stress characteristics analysis based on two-way FSI, the Navier-Stokes equations and Continuity equation used were transferred to arbitrary Lagrangian-Eulerian(ALE)coordinate system firstly, then were discretized with the special finite volume method adopting flow-condition-based interpolation(FBIC-C). The structure static mechanics equations used were established in rotation coordinate system, and were modeled with the finite element method. The two-way coupling ite-ration method between the fluid equations and the solid finite element equations was used to calculate until the coupling system is convergence. The structure calculation results based on two-way FSI showed that: the equivalent stress and deformation distribution of the runner in one-way and two-way FSI conditions are similar. The locations of maximum stress and deformation are the same. With the increasing of deformation, the relative difference of equivalent stresses gets higher. The highest relative difference values of equivalent stresses and deformations are both occurring at the maximum deformation point. Deformation mainly determines the difference between one-way and two-way FSI results. The one-way FSI is available if accuracy requirement is low at the condition of small deformation.
2013 Vol. 31 (10): 862-866 [Abstract] ( 1942 ) [HTML 1KB] [ PDF 1843KB] ( 1928 )
867 Time-varying analysis on hydraulic gradient for non-saturated soil in transient seepage
Xu Cundong, Zhang Shuo, Shi Guokun, Chang Zhoumei
To study the dynamic change of hydraulic gradient non-saturated in transient seepage, the differential equation of non-saturated seepage flow was established, and the relationship of matric suction and volumetric-water content was also taken into account in the equation. SEEP/W software was applied on simulating the seepage field in drawdown process and rise process, the change of hydraulic gradient at different depth was analyzed for exploring the rule of hydraulic gradient in different dam parts and the main periods of seepage failure. The simulation results show that hydraulic gradient at upstream side of the bottom, when sudden drawdown at 60%-70% of process, appears a peak which is 36.4 times than stable seepage period, it is the main periods of seepage failure. For the non-satura-ted soil at the upstream side of dam, hydraulic gradient increases slowly at 25%-50% of the water level rising period, but increases to 30-50 times rapidly after 50% of period, so it is the main period of seepage failure after 50% of slowly rising period. Variation of water level has almost no effect on the downstream. The results can provide a decision-making reference for flood regulation and operation management. 
2013 Vol. 31 (10): 867-873 [Abstract] ( 1220 ) [HTML 1KB] [ PDF 2169KB] ( 2255 )
874 Numerical simulation of excess output condition of a pump-turbine based on compressible calculation
Liu Jintao, Li Xiaopeng, Guo Lei, Wang Leqin
The flow in the runner was speed up at the excess output condition, and flow separation may occur in the runner and the pressure fluctuation was amplified. To study the hydraulic instability of a pump-turbine at excess output condition, a 3D pump-turbine model was set up. Unsteady,incompressible flow was used for numerical simulation using SST k-ω turbulence model under 110% rated power condition. The inner flow as well as the pressure fluctuation in the pump-turbine was analyzed. The law of evolution of pressure fluctuation in the field between the casing and the runner was investigated. Calculation results were compared with the experimental data. The results show that the amplitude of pressure fluctuation increases along the flow direction near the region of vanes. The dominant frequency of pressure fluctuation changes into half of the two times of blade passing frequency between guide vanes and stay vanes. The ratio of the relative amplitude of 9 fn frequency to the amplitude of mixture frequency decreases in the domain of guide vanes. The separation flow at the pressure side in the runner, as well as a large vortex rope in the draft tube, can be found at excess output condition.
2013 Vol. 31 (10): 874-878 [Abstract] ( 1408 ) [HTML 1KB] [ PDF 1981KB] ( 1396 )
879 Numerical prediction of flow in Francis turbine with long and short blades
Ma Yue, Zhang Haiku, Liu Demin, Liu Xiaobing
The 3D turbulent flow in HLA542-LJ-130 turbine runner under the typical small flow rate condition was simulated in CFX by solving the 3D N-S equation with SST turbulent model. The flow information in various flow passage components was obtained. The calculation results show that the pressure reduces uniformly from the volute inlet to the outlet of the guide vane, while the velocity vector increases uniformly. In addition, the symmetry of velocity and pressure distributions on the circumferential direction is good. The pressure reduces uniformly on the long and short blades from the inlet edge to the outlet edge of the blade, and the pressure distribution is relatively reasonable. There is no obvious recirculation and secondary flow on the working surface of the blade. The streamline distribution is smooth, and the pressure and velocity distributions on the inlet of the draft tube are basically symmetrical, while the pressure is uniformly distributed along the radial direction. There are vortexes in the straight taper section of the draft tube which has the same rotation direction with the runner. These vortexes develop to the end of the draft tube without obvious eccentricity, and they are weakened in the diffuser section. This study has important guiding significance for the selection and design of turbines in high-head hydropower stations.
2013 Vol. 31 (10): 879-883 [Abstract] ( 1314 ) [HTML 1KB] [ PDF 4385KB] ( 1533 )
884 Analysis on active control and aerodynamic characteristics of flexible airfoil
Ye Zhou, Zhao Haiyang, Gao Wei, Li Chun
In order to reduce the fatigue load of large scale wind turbine caused by the increasing blade length and weight, and to improve blade aerodynamic performance, the flexible deformation of airfoil was realized by considering the trailing edge swing angle as control variable, and the static lift-drag characteristics of both original and deformed airfoil were analyzed.Different influences on aerodynamic characteristics by changing the angle of attack or the swing angle were compared, and the static surface pressure distribution of the flexible airfoil and its dynamic lift-drag characteristics were studied. The results show that compared with the original airfoil, proper trailing edge deformation can improve the lift coefficient, and can reduce the resistance coefficient. Therefore, more efficient active control of flow field can be achieved. Alternate change of functions of airfoil pressure side and suction surface can be achieved by the airfoil flexible deformation, which can realize the control of airfoil aerodynamic performance. Compared with the rigid airfoil, both static and dynamic characteristics of flexible airfoil show different changing law.
2013 Vol. 31 (10): 884-887 [Abstract] ( 1744 ) [HTML 1KB] [ PDF 1862KB] ( 2027 )
888 Hydrostatic performance of a dry gas seal with bionic twin-path spiral grooves
Peng Xudong, Zhang Fengyun, Bai Shaoxian, Li Jiyun
For the problem of small gas film stiffness, poor opening performance and stability of a spiral-grooved face dry gas seal at a low speed, a new type of dry gas seals with bionic twin-path grooves was introduced based on the outline characteristics of a bird wings. It means that there is a piece of land in a spiral groove. The typical geometrical parameters defining the dry gas seal with twin-path spiral grooves were given. Reynolds equation was resolved by using finite difference method for gas film pressure distributions. The seal performances of such a new type of dry gas seal were studied by va-rying geometrical parameters of a twin-path spiral groove under hydrostatic conditions. The twin-path spiral groove geometrical parameters were optimized. In order to ensure the stiffness, sealing ability and opening characteristic of such a dry gas seal, perfect values of parameters are 0.4≤λ≤0.6, 0.6≤γ≤0.8, 2≤δ≤3,5 μm≤hg≤8 μm, 15°≤α≤20°, 0.7≤η≤1.3.
2013 Vol. 31 (10): 888-893 [Abstract] ( 1716 ) [HTML 1KB] [ PDF 1797KB] ( 1400 )
894 Spatial variability analysis of soil infiltration by calculating simplified G-A infiltration parameters using soil compaction
Liu Shanshan,, Xu Di,, Bai Meijian,, Li Yinong,, Wen Xinmin
In order to analyze the spatial variability of soil infiltration and provide guidance for irrigation system design and management, based on the observed data of initial water content, soil compaction, clay content and soil infiltration at typical points, the rationality of calculating simplified G-A infiltration parameters using soil compaction were analyzed by means of multiple linear regression me-thod. Furthermore, spatial variability of soil infiltration was also discussed using semi-variance analysis at different basin sizes. The results show that there is a high correlation among soil compaction, soil texture, soil structure and soil water content, meanwhile satisfactory significance was reached in its regression relevance with soil infiltration parameters. Thus it is feasible to calculate simplified G-A infiltration parameters using soil compaction. When the basin size expanded from 0.5 hm2 to 3.0 hm2, the variation coefficient of G-A infiltration parameters were between 0.1 and 1.0. Medium spatial variability of G-A infiltration parameters were found at different basin sizes. The semi-variogram of G-A infiltration parameters could be described by spherical model, and the spatial structural correlation were medium. No significant differences in spatial variation of infiltration parameters were found among different basin sizes. 
2013 Vol. 31 (10): 894-900 [Abstract] ( 1277 ) [HTML 1KB] [ PDF 2159KB] ( 1364 )
901 Effect of different drip irrigation threshold on water use and biomass of melon in solar greenhouse
Niu Yong,, Liu Honglu,, Wu Wenyong,, Zhang Baolong, Wang Kewu
In order to explore appropriate irrigation mode of melon, effect of drip irrigation with diffe-rent irrigation threshold on water utilization and biomass of melon in greenhouse were investigated. The low irrigation threshold was designed based on the proportion of irrigating substrate moisture content with the substrate feild capacity(FC), and treatments including 90% of FC(T1), 75% of FC(T2)and 60% of FC(T3). Results show that the lower irrigation threshold is good at increasing leaf area and stem diameter, but the plant height is not sensitive with it. The yield of T2 is the highest followed by T3 and T1. The root is distributed in a circle with a radius of 20 cm in the horizontal direction, and is distributed in the depth of 40 cm in the vertical direction. The water use efficiency(WUE)of T3 is the highest followed by T1 and T2. The highly efficient irrigation schedule is made with the value of crop factor(Kc)in different periods are 1.81, 1.61, 2.21 and 2.19. 
2013 Vol. 31 (10): 901-906 [Abstract] ( 1821 ) [HTML 1KB] [ PDF 1312KB] ( 1518 )
907 Effect of straw on soil evaporation of winter wheat
Hao Zhipeng,,, Dong Qinge,, Feng Hao,, Wang Zikui,
Based on the data of two fertilization treatments in field experiments(matching use of straw and chemical fertilizer(S)and general chemical fertilizer(R)), soil evaporation, the correlation between the proportion of soil evaporation in evapotranspiration and leaf area index, together with the correlation between soil water content and leaf water content throughout the growing period of winter wheat, were compared and analyzed. The results show that, under both treatments of “S” and “R”, the soil evaporation of winter wheat during the whole growing period can be indicated with the changing law of “W”, i.e. “high-low-high-low-high”. Treatment method “S” could restrain the soil evaporation of winter wheat effectively, with averaging inhibition rate of evaporation 9.96% during the whole growing period, and the inhibition rate of evaporation can be indicated with the changing trend of “high-low-high-low” along with the growing period. Moreover, the leaf area index is much hi-gher, while the proportion of soil evaporation in evapotranspiration is much lower under the treatment method “S” than the treatment method “R”. So the treatment method “S” is beneficial to the leaf growth and can help to reduce the proportion of soil evaporation in evapotranspiration. After closing the row of winter wheat, the leaf water status of winter wheat could be understood by monitoring the water content of soil in depth of 40-60 cm and 60-80 cm.
2013 Vol. 31 (10): 907-913 [Abstract] ( 1690 ) [HTML 1KB] [ PDF 1264KB] ( 1488 )
914 Effect of rewater on transport of water and nitrogen under water storage pits irrigation
Yin Yanzhe, Ma Juanjuan, Sun Xihuan, Guo Xianghong
In order to clarify the effect of rewatering after irrigation(rainfall)on transport of water and nitrogen, as well choose a reasonable way of irrigation methods, by means of indoor model test, the impact of the different rewatering volume(140.1,228.7,400.5 mm)and different rewatering interval(1,5,10 d after irrigation)on the migration of water and nitrogen was studied. The results show that the soil moisture content increases after rewatering. When the rewater volume is up to 1.73 L,the range of 30-80 cm depth soil moisture rate can reach more than 80% of the field capacity. The more rewatered or the shorter the interval time of rewatering was, the more uniform the moisture content distribute can be obtained. Nitrate has features of migrating with the soil water movement easily and accumulating at the wetting front. The nitrate nitrogen′s concentration of the soil near the pit wall reduces after rewatering, and the peak of nitrate nitrogen′s concentration is to the far forward. The more rewatering or the shorter the interval time of rewatering is,the farther nitrate nitrogen can be transported. The ammonium nitrogen of the soil near the pit wall decreases slightly, while the ammonium nitrogen of the soil far from the pit has a slight increasing. The more rewatering or the shorter the interval time of rewatering is, the larger the effect on ammonium nitrogen concentration can be obtained and the more uniform distribution of the ammonium nitrogen can be observed.
2013 Vol. 31 (10): 914-920 [Abstract] ( 1541 ) [HTML 1KB] [ PDF 760KB] ( 1588 )
排灌机械工程学报
　

WeChat QR code
　

News

 　
· Call for paper of The 14th Asian International Conference on Fluid Machinery(AICFM14)
· Call for paper of the 2nd International Symposium of Cavitation and Multiphase Flow (ISCM 2016)
· JDIME have be selected for the 2015-2016 China Science Citation Database (CSCD)
· CALL FOR PAPERS and 2nd ANNOUNCEMENT"The 7th International Conference on Pumps and Fans(ICPF2015)"
· The journal won the first prize of "excellent China sciencepaper online journal" again
· WeChat is Running
· A New Column “Irrigation and Drainage Equipment Manufacturing Technology”Setting Up
· CALL FOR PAPERS “8th INTERNATIONAL SYMPOSIUM ON PUMPING MACHINERY”
　　　　　　　　        　　More 
　

WeChat QR code

主管单位
 江苏省教育厅
主办单位
 江苏大学
协办单位
 中国农业机械学会排灌机械分会
 国家水泵及系统工程技术研究中心
 中国农业工程学会农业水土工程专业委员会
主　　编
 袁寿其
编辑出版
 《排灌机械工程学报》编辑部
责任编辑
徐云峰  张文涛 陈建华
谈国鹏  朱漪云 盛    杰
　

Links

 　
· KSB
· National Research Center of Pumps
　　　　　　　　        　　More 
 

Copyright © 2011 Journal of Drainage and Irrigation Machinery Engineering
Support by Beijing Magtech Co.Ltd   E-mail: support@magtech.com.cn