[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
 
2018 Vol.36 Issue.5
Published 2018-05-25

article
article
1
2018 Vol. 36 (5): 1- [Abstract] ( 145 ) [HTML 1KB] [ PDF 45853KB] ( 399 )
2
2018 Vol. 36 (5): 2- [Abstract] ( 130 ) [HTML 1KB] [ PDF 1138KB] ( 415 )
369 Effect of cavitation flow on energy transfer in nuclear main pump
CHENG Xiaorui,*, FU Li, BAO Wenrui
In order to study influences of cavitating flow on energy transfer in nuclear main pumps, the cavitating flow field in a nuclear main pump model was carried out under design condition using the RNG k-ε turbulence and Rayleigh-Plesset cavitation models, then vapour bubble distribution features in the impeller were attained. The influences of cavitating flow on the energy transfer in the impeller were studied under different cavitation conditions by analysing variations of fluid kinetic and sta-tic heads along the two streamlines on the shroud and hub. Results showed that the energy of fluid was provided by the impeller in the middle and after-middle portions of blade, and the working capacity of blades decreased gradually from the shroud to the hub. Cavitation interfered with the flow in the impeller, leading to an increased relative velocity and a decreased pressure in cavities, and the working capacity of blades was almost zero in a zone with dense vapour bubbles. In non-cavitation zones, the kinetic head rose but the static head declined along the streamlines with the development of cavitation. Because the decrease in the static head was greater than the increase in the kinetic head, the pump head and efficiency had to be reduced. In addition, with the development of cavitation, the sudden change in both heads were intensified in the cavitation zones, resulting in an increased hydraulic loss in the impeller, eventually, the pump head and efficiency dropped off even further.
2018 Vol. 36 (5): 369-376 [Abstract] ( 705 ) [HTML 1KB] [ PDF 3768KB] ( 778 )
377 Internal flow and analysis of its unsteady characteristics in centrifugal pump with ultra-low specific-speed
CHEN Jie, WANG Yong, LIU Houlin, SHAO Chang, ZHANG Xiang*
In order to explore internal flow and its unsteady characteristics in ultra-low specific-speed centrifugal pumps more comprehensively, an ultra-low specific-speed centrifugal pump with a specific-speed ns=25 was chosen as a study object. Then numerical simulations of the unsteady three-dimensional fluid flow in the pump were carried out. Finally, the internal flow field, radial thrust on the impeller and the pressure fluctuation of fluid in each section of the volute were analyzed. The results show that there appears vortices in various sizes and numbers in flow channels of the impeller under different flow conditions. A high velocity zone is found in two adjacent channels near the tongue, however, the zone disappears gradually with the increase of flow rate. Under high flow rate conditions, the area of the low velocity zone decreases gradually, the size and number of vortices reduce steadily, and the rela-tive velocity distribution in the impeller becomes uniform gradually. The orientation and magnitude of radial thrust on the impeller vary constantly, showing a hexagram pattern. The amplitude of radial thrust decreases gradually with increasing flow rate, but its main excitation frequencies are all the blade passing frequency or its integer multiples.The peak pressure fluctuation in each section of the volute decreases along the flow path and the main excitation frequencies are all the blade passing frequency or its integer multiples. This fact suggests that the impeller-volute interaction is one major factor influencing pressure fluctuation in the volute.These results have provided useful reference for optimum design of the ultra-low specific-speed centrifugal pump and selection of its feasible operating flow rate range.
2018 Vol. 36 (5): 377-383 [Abstract] ( 563 ) [HTML 1KB] [ PDF 2260KB] ( 884 )
384 Runaway characteristics of two-way passage axial-flow pump installation
WANG Maiqi, LI Yanjun*, YUAN Shouqi, MENG Fan
In order to gain runaway characteristics of two-way passage axial-flow pump installation, the axial-flow pump model with two-way flow passage installation in Zongyang Pump Station was used as an investigated object. The unsteady flow field in the installation was simulated numerically by using CFX software, based on the RANS equations and RNG k-ε turbulence model. The runaway speeds and flow rates were obtained under different heads. Finally, the unit runaway speed was worked out.The correctness of the numerical simulation was validated by comparison with the experimental results. The internal flow field in the pump installation shows an unstable pattern behind the pump and significant numbers of vertex occur in the outlet passage. The pressure distribution is irregular in the middle of the blade suction side, and a high pressure zone exists on the blade pressure side near the leading edge and on the blade suction side near the trailing edge, respectively. Moreover, the zone area increases with increasing runaway head. Flow separation exists at the blade trailing edge, and a low velocity region exists on the blade leading edge. The results can provide a good reference for design and safe operational management of the axial-pump installation.
2018 Vol. 36 (5): 384-390 [Abstract] ( 602 ) [HTML 1KB] [ PDF 2839KB] ( 865 )
391 Characteristics of flow through gap of interstage seal in supercritical boiler feed pump
LIU Gang, FU Qiang*, ZHU Rongsheng, WANG Xiuli, ZHANG Benying, LI Mengyuan
To study the characteristics of internal flow in the gap of interstage seal in supercritical boi-ler feed pumps, a few interstage seal models with various gap sizes were established and the fluid flows in these seals were simulated numerically. The pressure and velocity distributions in the axial and circumferential directions, and the pressure variation along the axial direction were calculated under a pulse inlet pressure. The results show that the fluid hydrostatic pressure and velocity have three variation stages through the seal in the axial direction, namely sharp drop, ascendant and linearly descen-dent stages. The greater the gap′s size is, the smaller the static pressure is, and the faster the velocity is. The static pressure distribution is not uniform in the circular cross-sections and presents a certain periodicity in the circumferential direction. In the annular cross-sections the high-velocity region appears near the rotating inner wall, but the low-velocity region occurs near the stationary outer wall. In addition, under a pulse inlet pressure, the pressure pulsating frequency in the middle and at the outlet of the seal is the same as the frequency at the inlet. The tail pressure is mainly determined by the outlet pressure, thus it fluctuates only within a certain amplitude.
2018 Vol. 36 (5): 391-396 [Abstract] ( 558 ) [HTML 1KB] [ PDF 2262KB] ( 845 )
397 Experimental study on sediment transport in river channel based on pneumatic lifting technology
CHEN Qiuliang, WU Shijing, LI Xiaoyong, WANG Aihua*
In order to examine the effectiveness of pneumatic lifting technology in river dredging processes, a sediment transport test platform using the pneumatic lifting technology was set up based on the usual condition of 70% dimensionless immersion depth. At 0-4.5 m/s air inlet velocities, a series of pneumatic lift experiments were carried out to identify the air inlet velocity for the optimum lif-ting efficiency. Meanwhile, the flow patterns at different air inlet velocities, especially at 0.6 and 1.0 m/s, were analyzed based on the image processing function in Matlab. As a result, the solid particle motion characteristics near the optimum lifting efficiency were obtained. It is shown that the solid particle flow patterns and mention characteristics are directly affected by the air inlet velocity. In a fixed immersion depth, the sand lifting efficiency is determined by the air inlet velocity. By studying the flow patterns at various air inlet velocities, the reasons for the formation of different flow patterns have been clarified. When the inlet velocity is 1.0 m/s, the gas phase is fully dispersed into uniformly-sized small bubbles, and strong momentum exchanges take place in gas, liquid and solid phases. Consequently, most of the kinetic energy of the gas phase is transferred into the solid and liquid phases, and the lifting efficiency is the highest. At the same time, the flow pattern is also the optimum for airlift. Establishing the relationship between the dredging efficiency and the air inlet velocity by experimentation, the feasibility of pneumatic lifting technology in river channel dredging has been confirmed.
2018 Vol. 36 (5): 397-403 [Abstract] ( 470 ) [HTML 1KB] [ PDF 4196KB] ( 911 )
404 Numerical simulation of end surface erosion characteristics of hydro-turbine guide vane
HAN Wei,, CHEN Yu, LIU Yi,*, LI Guangxian, WANG Jie, WANG Tengda
To study the solid-liquid two-phase flow features in the clearances between guide vane end surfaces and casing, as well as the erosion condition of two end surfaces, the unstead three-dimensio-nal flow in a cylinder and a backward-facing step flow channel, which is a simplified model of the end clearance flow in a real hydro-turbine guide vane, was numerically simulated based on the RNG k-ε turbulence model and discrete phase model(DPM)in Fluent. In simulations, the solid particle vo-lume fractions were 1%, 5%, 7% and 10%, the particle diameters were 0.020, 0.050, 0.075 and 0.100 mm, and different inlet velocities were used. Through steady numerical simulations, the distribution of average erosion rate on the upper and lower end surfaces was obtained, and the erosion pattern and locations were analyzed. The results indicate that the distribution of average erosion rate in flow field is closely related to the physics models and the parameter settings for the two-phase flow. With increasing inlet liquid velocity and particle volume fraction, the average erosion rate augments. The erosion positions mainly are located in the front of the cylinder, the reattachment point downstream the step and the outlet of the step. The maximum average erosion rate is about 2.0×10-6 kg/(m2·s). With increasing particle diameter, the average erosion rate decreases due to an increasing inertial force. When the particle diameter is less than 0.020 mm, heavier erosion occurs in comparison with the rate at large diameters, particularly, the maximum average erosion rate is about 2 times the rate at 0.100 mm particle diameter.
2018 Vol. 36 (5): 404-412 [Abstract] ( 552 ) [HTML 1KB] [ PDF 9641KB] ( 753 )
413 Numerical simulation on aerodynamic characteristics of vertical axis wind turbine with eccentric rotor structure
LI Yan,*, WU Zhicheng, TAGAWA Kotaro, FENG Fang,, ZHANG Tingting, BAI Rongbin, LI Jianye
A rotor with eccentric structure was proposed in order to improve the performance of straight-bladed vertical axis wind turbine(SB-VAWT). Then, the self-starting capacity and output power were enhanced by increasing the effective acting radius of blade on the rotor shaft. Numerical simulations were carried out on a SB-VAWT rotor with six eccentricities, respectively. NACA0018 airfoil was used as rotor blade section profile. The starting torque and power coefficients were predicted. The effects of eccentricity on the aerodynamic performance were analyzed. The simulated results show that a proper eccentricity can diminish negative starting torque coefficient in some degrees at a few azimuth angles, resulting in a smooth torque coefficient curve. Consequently, the starting performance of SB-VAWT is improved effectively. Furthermore, a suitable eccentricity can increase the rotor output po-wer, and the maximum power coefficient can be raised as high as 12% compared with an ordinary rotor.
2018 Vol. 36 (5): 413-419 [Abstract] ( 483 ) [HTML 1KB] [ PDF 2626KB] ( 853 )
420 Numerical simulation of pressure distribution in bristle seal for turbomachinery
KANG Yuchi ,, LIU Meihong*, WANG Xueliang, TAN Yongfa, LIU Jinbin
In order to further study the pressure distribution in bristle seals, a uniformed two-dimensional closed staggered tube bundle model representing a bristle pack cross-section was proposed and the fluid flow through the bundle was solved by computational fluid dynamics(CFD)method. Accor-ding to the critical Reynolds number for boundary layer transition, a new method was proposed to decide the fluid flow regime in the bundle. The pressure and velocity distributions in the bundle were studied under various pressure differentials across the seal. The influences of distance between bristles and number of circumferential bristle rows on the pressure distribution were tackled. It is shown that the pressure distributions in the uniformed two-dimensional closed staggered tube bundle model agrees well with the previous experimental data. The pressure distributions are like “V”, while the velocity distributions are like the inverted “V”. The pressure borne by the rear 1/3 part of the bristle pack is higher than that by the front 2/3 part. Moreover, the percentage of the pressure differential borne by the last 5 bristle rows increases with increasing total pressure differential. The pressure differential borne by the last bristle row is higher than that by a few rows in front of it. A reduced distance between bristles can allow the pressure to be distributed more even from one row to another. Bristles equally spaced can ensure an even pressure distribution rather well. Increasing the number of rows can also have the same effect. 
2018 Vol. 36 (5): 420-425 [Abstract] ( 561 ) [HTML 1KB] [ PDF 1536KB] ( 916 )
426 Correction of parameters in Angstrom formula and analysis of total solar radiation characteristics in Huaibei plain
YUAN Hongwei,, YUAN Xianjiang,, TANG Guangmin,, CUI Yi, JIANG Shangming,
Based on the total solar radiation data observed by automatic meteorological equipment in the Xinmaqiao Experimental Station, Anhui province, during 2011—2016, the empirical coefficients a and b in the Angstrom formula were calibrated by least squares method and genetic algorithm. Additionally, ET0 and total solar radiation calculated by the calibrated values were compared with the recommended values by FAO. Based on the optimized empirical parameters and the data observed in five typical meteorological stations located in Dangshan, Bozhou, Suxian, Bengbu and Fuyang, the temporal and spatial distribution characteristics of the total solar radiation in the Huaibei plain were analyzed. The results show that the recommended values of a and b by FAO are unsuitable to the total solar radiation in the Huaibei plain because of overestimated Rs and ET0. The calibrated values by the least squares method and genetic algorithm can result in more accurate Rs and ET0. In 1955—2014, the average daily total solar radiation presents a downtrend from north to south in the plain, and the decline is larger in the north than in the south. The year of 1980 is a turning point before that adaily total solar radiation declined tendency is not obvious, but after that the radiation is declined obviously. The seasonal distribution characteristics of Rs from the largest to the smallest are: summer> spring> autumn>winter. The yearly and seasonally average Rs distributions are higher in the north and lower in the south generally, but there is a difference in Rs locally. Besides, the monthly Rs shows a unimodal distribution, its maximum is in June and the minimum is in December. These results can provide a reference for accurately calculating Rs and ET0 based on conventional meteorological data in the plain.
2018 Vol. 36 (5): 426-432 [Abstract] ( 427 ) [HTML 1KB] [ PDF 1928KB] ( 985 )
433 Groundwater quality evaluation based on dynaset pair analysis model
HE Fujuan*, LI Wangcheng, YAN Wenjie
In terms of the drawback such as relatively fixed weights for evaluation indexes in existing water quality evaluation methods, a water quality evaluation method was proposed based on variable weights. Firstly, a multi-index groundwater quality evaluation system was established. Then, entropy weight method and analytic hierarchy process were used to calculate the objective and subjective weights, respectively. The two weights decided were used to determine the variable weights of an index, which could vary with index itself. Thirdly, the connection number in dynaset pair analysis was extended to 5 from 3, and the variable weights was introduced into this improved set pair analysis model; Eventually, a variable weight-based set pair analysis model was developed to evaluate groundwater quality. This model was applied to assess the quality of groundwater in Dawukou District, Shizuishan of Ningxia. Results show that the quality of the water at monitoring points 1, 2 and 5 is in level I but in level III at monitoring points 3, 4, 6 and 7. These evaluations have accounted for geological, hydrogeological conditions and human activities in the studied areas and are verified to be scientific and reasonable. In comparison with the comprehensive evaluation, attribute recognition and fuzzy matter-element methods, the result evaluated by variable weight set analysis model is more objective and reasonable, and has better practicability and scientificity.
2018 Vol. 36 (5): 433-438 [Abstract] ( 492 ) [HTML 1KB] [ PDF 1268KB] ( 724 )
439 Effects of fertilizer solution concentration and biomass content on infiltration characteristic of moistube irrigation
LI Yilin, LIU Xiaogang*, LIU Yanwei, YANG Qiliang, TANG Jiankai, DENG Xiaojun
In order to identify effects of fertilizer solution concentration and biomass content on soil water infiltration characteristics in moistube irrigation where fermented peanut shell power was used as mixed biomass, a series of indoor soil box simulation experiments were performed. In the experiments, the fertilizer solution concentration was at three levels(F0-pure water: 0 mg/L, FL- low concentration: 200 mg/L, FH-high concentration: 400 mg/L), the mixed biomass content was at four levels(B0-natural air-dry soil: 0 g/kg, BL-low mixed content: 15 g/kg, BM-moderate mixed content: 30 g/kg, BH-high mixed content: 45 g/kg), and infiltration rate, cumulative infiltration, wetted soil volume and distribution characteristics of soil moisture were examined. The results indicate that the fertilizer solution concentration and mixed biomass content have a statistically significant effect on the initial infiltration rate, steady infiltration rate, cumulative infiltration and average content of soil moisture. Compared with the control treatment F0B0, increasing fertilizer solution concentration and biomass content has improved the initial infiltration rate by 13.02%-44.85%, the steady infiltration rate by 13.50%-48.78%, the cumulative infiltration by 5.65%-56.62% and the average content of soil moisture by 6.62%-30.09%, respectively. The cumulative infiltration in terms of time is accorded with Kostiakov model. The wetted soil volume increases with increasing fertilizer solution concentration and biomass content, and can be fitted with a quadratic polynomial of infiltration time. The cross-sectional area of wetted soil and the uniformity coefficient of moistube irrigation increase with increasing fertilizer solution concentration and biomass content. 
2018 Vol. 36 (5): 439-447 [Abstract] ( 477 ) [HTML 1KB] [ PDF 1775KB] ( 693 )
448 Numerical simulation analysis of energy conversion in hydraulic turbine of hose reel irrigator JP75
LU Jing*, CHENG Jun
In order to carry out energy conversion analysis and parameter optimization for the hydraulic turbine in hose reel irrigator JP75, its internal flow at a rotational speed of 250 r/min was numerically simulated by using CFD technique. According to the pressure and the velocity contours predicted, the unreasonably designed bend and throat are responsible for low turbine efficiency. Through an analysis of the internal flow field, it is found that the turbine blades in the inlet and outlet are improperly designed, resulting in a large number of vortices in the blade clearance to generate a partial energy loss. The energy conversion in the jet section and runner was calculated, the average conversion efficiencies are 26.31% and 45.44%, respectively. Obviously, these conversion efficiencies are fairly low. On the basis above, the design parameters of the hydraulic turbine were optimized. The optimized nominal diameter, jet diameter and water head are 0.201 m, 0.021 m and 13.65 m, respectively.
2018 Vol. 36 (5): 448-453 [Abstract] ( 570 ) [HTML 1KB] [ PDF 5347KB] ( 880 )
454 Attitude control of pesticide spraying quadrotor aircraft based on fuzzy PID
JING Xuedong, PAN Xiang*, WANG Zetao
In order to realize a more stable attitude control for quadrotor aircrafts, a quaternion kinematical equation was established, and analytical and numerical solutions of the equation were given respectively, then the Euler angles were obtained. To identify the impact of variable loads on the control effect when a pesticide spraying quadrotor aircraft was working, a fuzzy PID controller was designed. The reliability of the controller was validated by using Matlab/Simulink simulations in comparison with the traditional PID controller. Additionally, a quadrotor aircraft test platform was established by programming the control algorithm on the stm32 flight controller. In the experiment, the control effect of the fuzzy PID was compared with the traditional PID by changing the weight of the aircraft. The overshoot of the fuzzy PID is decreased by 22% and 30%, the rising time is reduced by 0.06 s and 0.08 s, and the settling time is shortened by 0.70 s and 0.80 s, compared with the traditional PID, before and after the weight of the aircraft is changed. The results show that this fuzzy PID control system has the advantages of faster response, less overshoot, etc. than the traditional PID control system, and can meet the requirements on control of pesticide spraying quadrotor aircraft even better.
2018 Vol. 36 (5): 454-460 [Abstract] ( 554 ) [HTML 1KB] [ PDF 1558KB] ( 870 )
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