EXPERIMENTAL STUDY ON BED RESISTANCE CHARACTERISTICS OF NONUNIFORM SEDIMENT

1.　 INTRODUCTIONThe resistance characteristics of a fluvial river are in close relation with the dischargeand sediment-carrying capacity of the flow and it is a basic problem of river dynamics.Un-der natural circumstances,the bed of a fluvial river is composed of nonuniform sediment.Bed material size and nonuniform property are important factors affecting bed roughnesswhich is the most importantfactor of surface resistance.Early studieson bed resistance characteristicswasfocused on unifo…     

RESISTANCE OF FLOW OVER ROUGH BED

In this paper,the flow resistance in a flume with rough bed was studied,and the criteria of 2-dimensionalflow were obtained.The effects of bed roughness on Manning coefficient n and Chézy coefficient C were also dis-cussed,and the experimental results indicate that n and C can be taken as constants for small-scale roughness case.     

STUDY OF TRIMARAN WAVEMAKING RESISTANCE WITH NUMERICAL CALCULATION AND EXPERIMENTS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＯｎｅｏｆｔｈｅｍｏｓｔｓｉｇｎｉｆｉｃａｎｔｏｐｅｒａｔｉｎｇｃｏｓｔｓｏｆｖｅｓｓｅｌｓｉｓｔｈｅｆｕｅｌｒｅｑｕｉｒｅｍｅｎｔｆｏｒｐｒｏｐｕｌｓｉｏｎｓｏｔｈｅｒｅｉｓａｓｔｒｏｎｇｄｅｓｉｒｅｔｏｄｅｓｉｇｎｖｅｓｓ     

THEORETICAL AND EXPERIMENTAL STUDY ON THE CONICAL SWIRLING WATER JET FLOW

This paper is concerned with theoretical and experimental study on theconical swirling water jet flow.Based upon the theoretical analysis,the experiment on thestructural characteristics of swirling water jet flow including the velocity and pressure dis-tribution laws,on which the parameters of the jet,nozzle and directional blades havemore or less influence,was carried out in CSSRC by using a 3-D LDV in order to optimizea new high-efficiency jet instead of swirling drilling bit for rock-breaking and continuouslydrilling,and to meet the demand of radial horizontal drilling technology.Meanwhile basedon the experimental results,the numerical simulation was conducted for the conicalswirling water jet in the immersed well-bottom flow by solving the RANS equations in the3-D body-fitted coordinate system with the k-ε turbulence model.The numerical resultsare consistent with the experimental data,and lead to some conclusions which are impor-tant for applying the conical swirling water jet to the petroleum drill     

EXPERIMENTAL STUDY ON VELOCITY PROFILE OF SUBMERGED ABRASIVE SUSPENSION JET FLOW

1. INTRODUCTIONAbrasive Water Jet (AWJ), has been developed the into a remarkable and extensively used cutting technology in last two decades. In recent years, the polymer PAM has generally been applied to jetting fluid to further increase the abrasive ve…     

NUMERICAL SIMULATION OF THE EFFECT OF FILLET FORMS ON APPENDAGE－BODY JUNCTION FLOW

ＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＴＨＥＥＦＦＥＣＴＯＦＦＩＬＬＥＴＦＯＲＭＳＯＮＡＰＰＥＮＤＡＧＥ－ＢＯＤＹＪＵＮＣＴＩＯＮＦＬＯＷＬｉＤｉｎｇ；ＺｈｏｕＬｉａｎ－ｄｉ（ＣｈｉｎａＳｈｉｐＳｃｉｅｎｔｉｆｉｃＲｅｓｅａｒｃｈＣｅｎｔｅｒＰ．...     

ENERGY DISSIPATION AND CALCULATION OF RESISTANCE AND VELOCITY OF DEBRIS FLOW

ＥＮＥＲＧＹＤＩＳＳＩＰＡＴＩＯＮＡＮＤＣＡＬＣＵＬＡＴＩＯＮＯＦＲＥＳＩＳＴＡＮＣＥＡＮＤＶＥＬＯＣＩＴＹＯＦＤＥＢＲＩＳＦＬＯＷＦＥＩＸｉａｎｇｊｕｎ１ａｎｄＸＩＯＮＧＧａｎｇ２ＡＢＳＴＲＡＣＴＢｅｃａｕｓｅｏｆｔｈｅｈｉｇｈｃｏｎｃｅｎｔｒａｔ...     

PRELIMINARY STUDY ON CIRCULATION HEIGHT OF CIRCULATION FLOW WITH THE HORIZONTAL AXIS

1.　INTRODUCTIONCirculationflowisoneofcommonflowpatternsinnaturalrivers.Astherotationaxisishorizontal,andismainlyperpendiculartothemainstream,thiskindofcirculationflowisusuallycalledthehorizontalaxiscirculationflow(Zhang,1996).Itusuallyappearsinlocalareaswherebedboundarieschangesuddenly.Forexample,itexistsincross-riverchanneldugforsunkingpipe,anddownstreamofanapronextension,andsoon.Thehorizontalaxiscirculationareaisalwaystheimportantplacewheresedimentdepositsorerodesandtheerodingordeposi…     

STUDY ON SIMILARITY LAWS OF A DISTORTED RIVER MODEL WITH A MOVABLE BED

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓａｎｉｍｐｏｒｔａｎｔｓｕｂｊｅｃｔｉｎｒｉｖｅｒｍａｎａｇｅｍｅｎｔｔｏｐｒｅｄｉｃｔｔｈｅｂｅｄｄｅｆｏｒｍａｔｉｏｎｉｎａｌｌｕｖｉａｌｃｈａｎｎｅｌｓｉｎａｆｌｏｏｄ .Ｐｈｙｓｉｃａｌｍｏｄｅｌｓｈａｖｅｂｅｅｎｕｓｅｄｅｘｔｅｎｓｉｖｅｌｙａｓａｎｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄ .Ｐｈｙｓｉｃａｌｍｏｄｅｌｓ ｐｅｒｍｉｔｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｔｈｅｃｏｒｒｅｓｐｏｎｄｉｎｇ ｐｒｏｔｏｔｙｐｅｆｌｏｗｓａｎｄｂｅｄｄｅｆｏｒｍａｔｉｏｎ ｑｕａ…     

AN EXPERIMENTAL STUDY ON INCIPIENT CAVITATION EROSION OF FLOOD DISCHARGE TUNNEL WITH ORIFICE

Serial grades of cement mortar specimens have been tested on the model of con-crete-lining flood discharge tunnel with orifice,The results show that incipient cavitation erosionnumber is much smaller than incipient cavitation number.Based on the principle of bubble dy-namics,the flow speed effect on incipient cavitation erosion number for cement mortar is pre-sented.     

SIZE DISTRIBUTIONS OF COARSE SAND BED LOAD IN TURBULENT FLOW FIELD

ＳＩＺＥＤＩＳＴＲＩＢＵＴＩＯＮＳＯＦＣＯＡＲＳＥＳＡＮＤＢＥＤＬＯＡＤＩＮＴＵＲＢＵＬＥＮＴＦＬＯＷＦＩＥＬＤ￥ＺｈａｎｇＨｏｎｇ－ｗｕ；ＷａｎｇＳｈａｎ（ＩｎｓｔｉｔｕｔｅｏｆＨｙｄｒａｕｌｉｃＲｅｓｅａｒｃｈＹｅｌｌｏｗＲｉｖｅｒＣｏｎｓｅｒｖ...     

NUMERICAL STUDY ON EFFECT OF WAVING BED ON THE SURFACE WAVE

1. INTROUCTION There have been lot of researches on the effect of the bottom on the surface wave, in which, most of them involved the fixed bottom with concave, convex, or periodical shapes [1-3]. It seems that very few ones on waving bed are available up…     

NUMERICAL AND EXPERIMENTAL STUDY ON LIQUID-SOLID FLOW IN A HYDROCYCLONE

Hydrocyclones are widely used in industry, of which the geometrical design using CFD techniques is gaining more popularity in recent years. In this study, the Euler-Euler approach and the Reynolds stress model are applied to simulate the liquid-solid flowfield in a hydrocyclone. The methodology is validated by a good agreement between experimental data and numerical results. Within the research range, the simulation indicates that the liquid-solid separation mainly occurs in the conical segment, and increasing conical height or decreasing cylindrical height helps to improve the grade efficiencies of solid particles. Based on these results, two of the same hydrocyclones are designed and installed in series to establish a liquid-solid separation system. Many experiments are then conducted under different conditions, in which the effects of the water cut and the second hydrocyclone on the separation are investigated. The results also confirm that smaller solid particles are more susceptible to the inlet conditions, and the second hydrocyclone plays a more important role as the water cut reduces.     

EXPERIMENTAL RESEARCH ON AERODYNAMIC PERFORMANCE AND EXIT FLOW FIELD OF LOW PRESSURE AXIAL FLOW FAN WITH CIRCUMFERENTIAL SKEWED BLADES

In this article, the low pressure axial flow fan with circumferential skewed rotor blade, including the radial blade, the forward-skewed blade and the backward-skewed blade, was studied with experimental methods. The aerodynamic performance of the rotors was measured. At the design condition at outlet of the rotors, detailed flow measurements were performed with a five-hole probe and a Hot-Wire Anemometer (HWA). The results show that compared to the radial rotor, the forward-skewed rotor demonstrates a wider Stable Operating Range (SOR), is able to reduce the total pressure loss in the hub region and make main loading of blade accumulating in the mid-span region. There is a wider wake in the upper mid-span region of the forward-skewed rotor. Compared to the radial rotor, in the backward-skewed rotor there is higher total pressure loss near the hub and shroud regions and lower loss in the mid-span region. In addition, the velocity deficit in the wake is lower at mid-span of the backward-skewed rotor than the forward-skewed rotor.     

HORIZONTAL 2-D BASIC EQUATIONS AND SIMULATION OF INTERCHANGE BETWEEN SUSPENDED SEDIMENT AND BED MATERIALS IN ALLUVIAL RIVER

A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the interchange between suspended sediment and bed materials in the Lower Yellow River. This model was used to simulate the erosion and deposition processes caused by the interchange between suspended sediment and bed materials in a sketch channel. The results show that these equations are well consistent with the laws of interchange between suspended sediment and bed materials. Furthermore, compared with previous models, it has important practical value not only because of strong theoretical foundation, but also for smaller amount of calculating work and convenient application in practice.     

NUMERICAL SIMULATION AND EXPERIMENTAL INVESTIGATION OF THE GUIDE-VANE FLOW AND THE INFLUENCE FROM THE LEAKAGE FLOW

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｈｙ ｄｒａｕｌｉｃｔｕｒｂｉｎｅｉｓｆｏｒｔｈｅｂｅｓｔｈｙｄｒａｕｌｉｃｅｆｆｉｃｉｅｎｃｙａｎｄｓｔａｂｉｌｉｔｙｉｎｏｐｅｒａｔｉｏｎ .Ｔｈｅｓｔａｂｉｌｉｔｙｏｆｈｙ ｄｒａｕｌｉｃｔｕｒｂｉｎｅａｎｄｉｔｓ ｐｅｒｆｏｒｍａｎｃｅｏｆｃａｖｉｔａｔｉｏｎｅｒｏｓｉｏｎａｒｅｃｌｏｓｅｌｙｒｅｌａｔｅｄｔｏｔｈｅｆｌｕｉｄｆｌｏｗｉｎｔｕｒ ｂｉｎｅｃａｓｉｎｇ ,ｓｔａｙｖａｎｅａｎｄｇｕｉｄｅ…     

0HORIZONTAL 2-D BASIC EQUATIONS AND SIMULATION OF INTERCHANGE BETWEEN SUSPENDED SEDIMENT AND BED MATERIALS IN ALLUVIAL RIVER

A set of new 2-D equations of interchange between suspended sediment and bed materials was serived by theoretical deduction based on the systematic summarization and assessment the previous studies of simulating the interchange between suspended sediment and bed materials in the Lower Yellow River. This model was used to simulate the erosion and deposition processes caused by the interchange between suspended sediment and bed materials in a sketch channel. The results show that these equations are well consistent with the laws of interchange between suspended sediment and bed materials. Furthermore, compared with previous models, it has important practical value not only because of strong theoretical foundation, but also for smaller amount of calculating work and convenient application in practice.