|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction显示文摘Experimental investigation was carried out to study the effect of suction positions and suction flow rates on the aerodynamic performance of a compressor cascade with a large camber angle. The ink-trace flow visualization was conducted and the flow fields of the cascade were also measured. Three types of boundary layer suction configurations are compared,i.e. the suction surface suction,the endwall suction and the compound suction. Experimental results show that the large amount of suction flow rate gains more losses reduction than the small amount for a certain proper suction configuration,but the speed of loss decline slows down as the suction flow rate goes on increasing. Boundary layer suction on the suction surface obviously enhances the ability of the boundary layer around the midspan to withstand the negative pressure gradient of the flow passage. The range of the suction surface corner is also decreased. If the suction slot locates in the corner separation region where severe separation has happened,the flow separation will be terminated at the slot and redevelop downstream. And boundary layer suction on the endwall mainly influences the endwall corner region in remarkably delaying,lessening and reorganizing the corner separation. While the whole flow field is remarkably improved at both midspan and the corner region in the compound suction schemes. At higher suction flow rates,the aerodynamic performance of the compressor cascade is better than that with boundary layer suction simply on the suction surface or on the endwall. When the suction flow rate is 1.5% of the inlet mass flow,the compound suction scheme achieves a maximum loss reduction of 17% compared with the cascade without boundary layer suction. | GUO Shuang1, CHEN ShaoWen1, LU HuaWei2, SONG YanPing1 & CHEN Fu1 1 School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China 2 Marine Engineering College, Dalian Maritime University, Dalian 116026, China | 2010 | Science China(Technological Sciences)2010，53，10： | 14 |
| 2 | 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 |
| 3 | Influence of root suction on tensile strength of Chrysopogon zizanioides roots and its implication on bioslope stabilization显示文摘Root tensile strength is an important factor controlling the performance of bio-slope stabilization works. Due to evapotranspiration and climate factors, the root moisture content and its suction can vary seasonally in practice and may not equal soil suction. The influences of suction and root moisture contents were investigated on Chrysopogon zizanioides(vetiver grass) root tensile strength. The root specimens were equilibrated with moist air in different suction conditions(0, 10, 20, and 50 kPa), prior to root tension tests. The root-water characteristic curve or relationship between root moisture and suction, was determined. The increase in suction resulted in decreased tensile strengths of the grass roots, particularly those with diameter of about 0.2 mm, which constituted 50.7% of all roots. For 1 mm roots, the tensile strength appeared to be unaffected by suction increase. The average root tensile strengths were used to estimate the root cohesion in slope stability analysis to find variation of safety factors of a bioengineered slope in different suction conditions. The analysis showed that the critical condition of slope with the lowest factor of safety would happen when the soil suction was zero and the root suction was high. Such condition may occur during a heavy rain period after a prolonged drought. | Krairoj MAHANNOPKUL Apiniti JOTISANKASA | 2019 | Journal of Mountain Science2019，16，2： | 10 |
| 4 | A combined application of micro-vortex generator and boundary layer suction in a high-load compressor cascade显示文摘In the current study, the effects of a combined application between micro-vortex generator and boundary layer suction on the flow characteristics of a high-load compressor cascade are investigated. The micro-vortex generator with a special configuration and the longitudinal suction slot are adopted. The calculated results show that a reverse flow region, which is considered the main reason for occurring stall at 7.9° incidence, grows and collapses rapidly near the leading edge and leads to two critical points occurring on the end-wall with the increasing incidence in the baseline. As the micro-vortex generator is introduced in the baseline cascade, the corner separation is switched to a trailing edge separation by the thrust from the induced vortex. Meanwhile, the occurrence of failure is delayed due to the mixed low energy fluid and main flow. The synergistic effects between the micro-vortex generator and the boundary layer suction on the performance of the cascade are superior to the baseline at all the incidence conditions before the occurrence of failure, and the sudden deterioration of the cascade occurs at 10.3° incidence. The optimal results show that the farther upstream suction position, the lower total pressure loss of the cascade with vortex generator at the near stall condition. Moreover, the induced vortex with a leg can migrate the accumulated low energy fluid backward to delay the occurrence of stall. | Shan MA Wuli CHU Haoguang ZHANG Xiangjun LI Haiyang KUANG | 2019 | Chinese Journal of Aeronautics2019，32，5： | 9 |
| 5 | Dual solutions in boundary layer flow of a moving fluid over a moving permeable surface in presence of prescribed surface temperature and thermal radiation Dual solutions in boundary layer flow of a moving fluid over a moving permeable surface in presence of prescribed surface temperature and thermal radiation Dual solutions in boundary layer flow of a moving fluid over a moving permeable surface in presence of prescribed surface temperature and thermal radiationDual solutions in boundary layer flow of a moving fluid over a moving permeable surface in presence of prescribed surface temperature and thermal radiation显示文摘An analysis of the heat transfer for a boundary layer forced convective flow past a moving permeable flat surface parallel to a moving fluid is presented. Prescribed surface temperature at the boundary is considered, A thermal radiation term in the energy equation is considered. The similarity solutions for the problem are obtained and the reduced ordinary differential equations are solved numerically. To support the validity of the numerical results, a comparison is made with the available results for some particular cases of this study. Dual solutions exist when the surface and the fluid move in the opposite directions. | Swati Mukhopadhyay | 2014 | Chinese Physics B2014，23，1： | 7 |
| 6 | Is routine drainage necessary after pancreaticoduodenectomy?显示文摘With the development of imaging technology and surgical techniques, pancreatic resections to treat pancreatic tumors, ampulla tumors, and other pancreatic diseases have increased. Pancreaticoduodenectomy, one type of pancreatic resection, is a complex surgery with the loss of pancreatic integrity and various anastomoses. Complications after pancreaticoduodenectomy such as pancreatic fistulas and anastomosis leakage are common and significantly associated with patient outcomes. Pancreatic fistula is one of the most important postoperative complications; this condition can cause intraperitoneal hemorrhage, septic shock, or even death. An effective way has not yet been found to avoid the occurrence of pancreatic fistula. In most medical centers, the frequency of pancreatic fistula has remained between 9% and 13%. The early detection and routine drainage of anastomotic fistulas, pancreatic fistulas, bleeding, or other intra-abdominal fluid collections after pancreatic resections are considered as important and effective ways to reduce postoperative complications and the mortality rate. However, many recent studies have argued that routine drainage after abdominal operations, including pancreaticoduodenectomies, does not affect the incidence of postoperative complications. Although inserting drains after pancreatic resectionscontinues to be a routine procedure, its necessity remains controversial. This article reviews studies of the advantages and disadvantages of routine drainage after pancreaticoduodenectomy and discusses the necessity of this procedure. | Qiang Wang Yong-Jian Jiang Ji Li Feng Yang Yang Di Lie Yao Chen Jin De-Liang Fu | 2014 | World Journal of Gastroenterology2014，20，25： | 7 |
| 7 | BASIC FLOW PATTERNS AND OPTIMUM HYDRAULIC DESIGN OF A SUCTION BOX OF PUMPING STATION显示文摘A numerical method based on 3 D turbulence flow was applied to simulate the flow pattern in suction boxes of six different types. In light of the computational results, the basic flow patterns in the boxes were revealed and a theoretical method to optimize hydraulically design of the suction box is developed. The box geometrical parameters, which influence the flow pattern in the box, could be optimized. The optimum criteria for the hydraulic design of the suction boxes of six types established, respectively. Furthermore, a summarization is given here based on the classification of the basic flow patterns in order to systematically understand the hydraulic design of suction boxes. | Lu Lin guang Yangzhou University, Yangzhou 225009, P.R.China (Received April 14, 2000) | 2000 | Journal of Hydrodynamics2000，12，4： | 6 |
| 8 | Experimental Studies on Modified Suction Caissons in Fine Sand Subject to Uplift Loading显示文摘A modified suction caisson(MSC), which was reported by the authors of this paper previously, comprises an external short-skirted structure that is added to a regular suction caisson(RSC). It has been proved that MSCs can improve the lateral bearing capacity and limit the deflection of the caisson compared with RSCs. A series of model tests were conducted to investigate responses of MSCs subject to uplift loading in saturated sand. The effects of external skirt dimensions on the uplift bearing capacity of MSCs were considered. In addition, the influences of the sealed top lid of the skirted structure on the uplift bearing capacity and the resulting passive suction of MSCs were also studied. It was found that the uplift bearing capacities of MSCs are 1.4-1.7 times that of RSCs. Moreover, test results in serviceable conditions show that the sealed external skirted structure of perspex-made suction caissons significantly contributed to the uplift bearing capacity as a result of passive suction. | Hanbo Zhai Dayong Li | 2017 | Transactions of Tianjin University2017，23，6： | 5 |
| 9 | Lateral Bearing Capacity of Modified Suction Caissons Determined by Using the Limit Equilibrium Method显示文摘The modified suction caisson(MSC) adds a short-skirted structure around the regular suction caissons to increase the lateral bearing capacity and limit the deflection. The MSC is suitable for acting as the offshore wind turbine foundation subjected to larger lateral loads compared with the imposed vertical loads. Determination of the lateral bearing capacity is a key issue for the MSC design. The formula estimating the lateral bearing capacity of the MSC was proposed in terms of the limit equilibrium method and was verified by the test results. Parametric studies on the lateral bearing capacity were also carried out. It was found that the lateral bearing capacity of the MSC increases with the increasing length and radius of the external skirt, and the lateral bearing capacity increases linearly with the increasing coefficient of subgrade reaction. The maximum lateral bearing capacity of the MSC is attained when the ratio of the radii of the internal compartment to the external skirt equals 0.82 and the ratio of the lengths of the external skirt to the internal compartment equals 0.48, provided that the steel usage of the MSC is kept constant. | LI Da-yong MA Shi-li ZHANG Yu-kun CHEN Fu-quan | 2018 | China Ocean Engineering2018，32，4： | 5 |
| 10 | SECONDARY INSTABILITY WITH RESPECT TO SPATIAL GROWING THREE-DIMENSIONAL SUBHARMONIC DISTURBANCES IN BOUNDARY LAYER FLOW WITH SUCTION显示文摘SECONDARYINSTABILITYWITHRESPECTTOSPATIALGROWINGTHREE-DIMENSIONALSUBHARMONICDISTURBANCESINBOUNDARYLAYERFLOWWITHSUCTION￥ZhaoGen... | Zhao, Gengfu | 1995 | Journal of Hydrodynamics1995，7，3： | 4 |
| 11 | Pulmonary artery sarcoma successfully treated by right pneumonectomy after definitive diagnosis显示文摘Pulmonary artery sarcoma(PAS)is a rare and lethal neoplasm that is usually diagnosed during surgery or autopsy.Early diagnosis and radical surgical resection offer the only chance for survival.However,making a preoperative histopathological diagnosis is quite difficult.We encountered a 57-year-old woman presenting a PAS that mimicked a pulmonary thromboembolism.After confirming a definitive diagnosis using a catheter suction biopsy,we successfully performed a right pneumonectomy via a median sternotomy without cardiopulmonary bypass.Eighteen months after surgery,no recurrence was observed. | Ryuta Fukai Kyu Rokkaku Yoshihito Irie Takao Imazeki Yoshiaki Katada Hiroyoshi Watanabe Yoshihiko Ueda Hideaki Miyamoto Masayuki Chida | 2013 | World Journal of Clinical Oncology2013，4，4： | 4 |
| 12 | Behavior of materials for earth and rockfill dams:Perspective from unsaturated soil mechanics显示文摘The basis of the design of earth and rockfill dams is focused on ensuring the stability of the structure under a set of conditions expected to occur during its life.Combined mechanical and hydraulic conditions must be considered since pore pressures develop during construction,after impoundment and in drawdown.Other instability phenomena caused by transient flow and internal erosion must be considered.The prediction of the hydromechanical behavior of traditional and non-traditional materials used in the construction of dams is therefore fundamental.The materials used for dam’s construction cover a wide range from clayey materials to rockfill.In a broad sense they are compacted materials and therefore unsaturated materials.A summary of the current level of knowledge on the behavior of traditional materials used in the construction of dams is presented in the paper.Regular compacted materials(with a significant clay fraction),rockfill and compacted soft rocks are studied with more detail.The latter are non-traditional materials.They are analysed because their use,as well as the use of mixtures of soil and rock,is becoming more necessary for sustainability reasons. | Eduardo E.ALONSO Rafaela CARDOSO | 2010 | Frontiers of Structural and Civil Engineering2010，4，1： | 3 |
| 13 | Review of methods for predicting in situ volume change movementof expansive soil over time显示文摘The soil movement information over time is required for the design of foundations placed in expansive soils. This information is also helpful for the assessment of pre-wetting and controlled wetting mitigation alternatives for expansive soils. Several researchers during the past fifteen years have proposed different methods for the prediction of the soil movements over time. The available methods can be categorized into(i) consolidation theory-based methods,(ii) water content-based methods, and(iii) suction-based methods. In this paper, a state-of-the-art of the prediction methods is succinctly summarized. The methods are critically reviewed in terms of their predictive capacity along with their strengths and limitations. The review highlights the need for prediction methods that are conceptually simple yet efficient for use in conventional engineering practice for different types of expansive soils. | Hana H. Adem Sai K. Vanapalli | 2015 | 岩石力学与工程学报2015，34，1： | 3 |
| 14 | Earth Pressure Distribution and Sand Deformation Around Modified Suction Caissons(MSCs) Under Monotonic Lateral Loading显示文摘The modified suction caisson(MSC) is a novel type of foundation for ocean engineering, consisting of a short external closed-top cylinder-shaped structure surrounding the upper part of the regular suction caisson(RSC). The MSC can provide larger lateral bearing capacity and limit the deflection compared with the RSC. Therefore, the MSC can be much more appropriate to use as an offshore wind turbine foundation. Model tests on the MSC in saturated sand subjected to monotonic lateral loading were carried out to investigate the effects of external structure sizes on the sand surface deformation and the earth pressure distribution along the embedded depth. Test results show that the deformation range of the sand surface increases with the increasing width and length of the external structure. The magnitude of sand upheaval around the MSC is smaller than that of the RSC and the sand upheaval value around the MSC in the loading direction decreases with the increasing external structure dimensions. The net earth pressure in the loading direction acting on the internal compartment of the MSC is smaller than that of the RSC at the same embedded depth. The maximum net earth pressure acting on the external structure outer wall in the loading direction is larger than that of the internal compartment, indicating that a considerable amount of the lateral load and moment is resisted by the external skirt structure. | LI Da-yong LI Shan-shan ZHANG Yu-kun CHEN Fu-quan | 2019 | China Ocean Engineering2019，33，2： | 2 |
| 15 | NUMERICAL STUDY ON THE FLOW AROUND A CIRCULAR CYLINDER WITH SURFACE SUCTION OR BLOWING USING VORTICITY-VELOCITY METHOD显示文摘A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LUdecomposition conjugate gradient scheme (MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too. | LING Guo-ping(凌国平) FANG Jian-wen(方健雯) | 2002 | Applied Mathematics and Mechanics(English Edition)2002，23，9： | 2 |
| 16 | Hydromechanical behavior of unsaturated expansive clay under repetitive loading显示文摘Compacted layers of expansive soils are used in different engineering projects,such as subgrades,engineered clay barriers,and buffers for radioactive waste disposal.These layers are exposed to a variety of stresses and wetting conditions during field serviceability.Coupling between hydraulic and mechanical repeated loading provides insight understanding to the induced progressive deformation of expansive clay.This study was conducted to investigate the hydromechanical behavior of unsaturated compacted expansive clay under repeated loadingeunloading(RLU)conditions.Two series of onedimensional(1D)oedometer tests were conducted under controlled matric suction up to 1500 kPa using the axis translation technique(Fredlund soil-water characteristic curve device,SWC-150).The first test series was carried out at different levels of controlled matric suction for non-repeated loading eunloading(NRLU)cycles.RLU cycles were applied in the second test series at different repetitivestress levels and under different levels of matric suction.The results indicated increasing axial wetting strainε_(a)(s),axial swell pressure ss(s),compression index C_(c)(s),and swell index C_(s)(s)with suction reduction.The estimated loadecollapse(LC)curves obtained from NRLU series(LCN)and RLU series(LCR)indicated increasing yield stress sy(s)with increasing suction.This is attributed to the developed apparent cohesion between soil particles,which in turn rigidifies the material response.Applying repetitive loading induced a notable reduction of compression index C_(c)(s)at the same level of suction,whereas swell index C_(s)(s)seems to be independent of repetitive loading.Finally,repetitive loading exceeding initial yield stresses results in plastic hardening and,hence,enlargement of yield stress locus(i.e.LCR curve). | Ahmed M.Al-Mahbashi Mosleh A.Al-Shamrani Mohammad F.Abbas | 2021 | Journal of Rock Mechanics and Geotechnical Engineering2021，13，5： | 2 |
| 17 | AN INVESTIGATION ON LIQUIDUS OF THE TERNARY SYSTEM NdCl_3-CaCl_2-LiCl显示文摘As one of a series of investigations carried out in our laboratory, the liquidus of the NdCl3-CaCl2-LiCl system which was determined by the DTA method is described here. So far as we know, this phase diagram is reported for the first time. | 郑朝贵 靳军 陈集林 叶于浦 | 1989 | Chinese Science Bulletin1989，34，14： | 1 |
| 18 | Magnetohydrodynamic stagnation-point flow of Sisko nanofluid over a stretching sheet with suction显示文摘A numerical investigation is presented to show the effects of thermo-diffusion on the hydromagnetic stagnation-point flow of Sisko nanofluid over a linearly stretching sheet by considering viscous dissipation and Joule heating with suction/injection.A suitable set of similarity transformations is considered in order to convert the basic partial differential equations into a set of coupled nonlinear ordinary differential equations.An efficient numerical method along with shooting technique is involved in older to solve the reduced governing basic equations.The influences of several emerging physical parameters of Sisko nanofluid on the profiles of velocity,temperature,solutal concentration,nanoparticle volume fraction,skin-friction coefficient,Nusselt number,and Sherwood number have been studied and analyzed in detail through graphs and tables.It is found that the skin friction coefficient decays more rapidly against the material parameter of Sisko fluid.ALso,it is noticed that the Brownian motion and thermophoresis parameter have the reverse effects on Sisko nanofluid Sherwood number.It is analyzed that the Nusselt number decreases with an increase in the values of thermophoresis parameter.Brownian motion parameter,and Eckert number,while its value increases with material parameter and Dufour solutal Lewis number.It is observed that the Sherwood number has ascending behavior for thermophoresis and.Brownian motion parameters,whereas nanofluid Sherwood number gets amplified with a hike in the nano Lewis number parameter for all the values of Brownian motion parameter. | Dulal Pal Gopinath Mandal | 2020 | Propulsion and Power Research2020，9，4： | 1 |
| 19 | EFFECTS OF TRANSVERSE OSCILLATIONS ON NATURAL CONVECTIVE FLOW INDUCED BY COMBINED THERMAL AND MASS DIFFUSIONS IN POROUS MEDIA显示文摘This paper studies the unsteady heat and mass natural convection in a highlyporous medium bounded by an infinite vertical porous wall. The unsteady sourceof the problem arises from the transverse oscillations in suction velocity offluids, The analytical results for the problem are obtained based on the methodof small parameter, and show that the natural circulation in the porous mediumis affected by this kind of oscillation. | WANG CHAOYANG TU CHUANJING, Department of Thermoscience and Engineering, Zhejiang University, Hangzhou, P. R. China | 1989 | Journal of Hydrodynamics1989，1，1： | 1 |
| 20 | Clinical application of flexible ureteroscopic sheath with controllable intraluminal pressure in treating ureteral stones显示文摘Objective:The purpose of the study was to assess the clinical efficacy and safety of a combined perfusion suction platform with pressure feedback control function and an ureteroscopic suction sheath that can measure the ureteropelvic pressure in implementing lithotripsies.Methods:Fifty-two patients who underwent lithotripsy under intelligent monitoring of ureteral intraluminal pressure from June 2016 to January 2018 were retrospectively recruited.The inclusion standard was stone diameter>1.5 cm but<2.5 cm.After the 12/14 Fr suction sheath was placed,manometer interface and suction interface of the sheath were connected to the platform via the pressure sensor and suction tube,respectively.The ureteroscope was connected to the platform perfusion pump,and the crushed stones were aspirated out under negative pressure.Results:According to the location of the stone,21(40.4%)cases were classified as upper ureteral stones,19(36.5%)were midureteral stones,and 12(23.1%)were lower ureteral stones.Forty-seven patients underwent successful primary sheath placement and lithotripsy with a mean operative time of 34.5(standard deviation 18.3)min.Retrograde stone migration did not occur.There were eight patients with hematuria postoperatively.Serious complication was 1.9% with one case of ureteral perforation.Stone clearance was 95.7% at Day 1e2 postoperatively,and 100% at Day 30 postoperatively.Conclusion:Ureteroscopic lithotripsy with intelligent pressure control using our device improved the efficiency of the lithotripsy and rate of stone clearance.The safety of the operation can be ensured.It is worth popularization and application in clinical practice. | Yuming Zhong Donghua Xie Chunxiang Luo Xiaohui Liao Tairong Liu Xiaoling Deng Lunfeng Zhu Leming Song | 2023 | Asian Journal of Urology2023，10，2： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员