Applied Mechanics and Materials Vols. 256-259

Abstract: Rouse equation, which was derived from the diffusion theory, is well known in the study of steady state suspended sediment transport over erodible beds. Although this equation being regarded as Rouse law could be applied effectively, it is unrealistic that the concentration at the free surface is always zero. In addition, for deriving the depth-averaged concentration, the numerical integration or the table lookup has to be performed. Bose and Dey[1] improved the Rouse equation using a modified sediment diffusivity in order to overcome the zero value concentration, but this equation can not be integrated analytically yet. In this paper, according to two equilibrium profiles respect to constant and linear diffusion coefficients, an approximate solution of the improved Rouse equation is given using a general weight-averaged method in order to be integrated analytically. Through verification with experimental data, the results show that the approximation of the improved Rouse equation behave generally better than itself, as well as the Rouse equation and van Rijn equation over the whole water depth. It is revealed that, nevertheless some empirical, this approximation is reasonable, and has higher accuracy. Moreover it can be integrated analytically.

Abstract: Environmental Fluid Dynamics Code (EFDC) was developed by Hamrick at Virginia Institute of Marine Science for estuarine and coastal applications. EFDC is a general-purpose modeling package for simulating three-dimensional flow, transport, and biogeochemical processes in surface water systems such as rivers, lakes, reservoirs, estuaries, wetlands and coastal regions. Use the 3-D numerical model EFDC simulated the density stratified flow in a slut. Compared the simulation and experimental data, the results showed that EFDC could accurately simulated the density stratified flow.

Abstract: This article discuss the hydrological and hydraulic calculation of the highway drainage, analyzing the formation mechanism and status of the highway stagnant water, by the analyzing of the functionality and the cost of engineering of linear drainage system, Pointing out the advantages of linear drainage.

Abstract: The present study make a deep analysis of the Chang TAN, Wu Yin, Tongshan Yuan,Wen Rui,Niu Tou mountain , Qian Tang River six large scale irrigation management status and conventional water distribution operation mode. We refer a promising method of optimal water allocation of irrigation canal system based on the former research.

Abstract: The background and principle of the annular flume technology were introduced. A complete literature review of the research progress by using the annular flume in China and other countries was presented including annular flume numerical simulation, experiments on the scene etc. On the basis of the existing progress, the potential application prospects of annular flume technology in the study of cohesive sediment characteristics are summarized briefly.

Abstract: In this paper, Steady-flow Integration Approach (SIA) and Volume of Fluid (VOF) method are both used to calculate the filling time of a ship lock. The values of filling time derived from these two different methods have the same order of magnitude. SIA is only used to give a quick but coarse estimation; however in the application of more time-consuming VOF approach, the fluctuations of water surface are additionally considered and computed, It provides a more precise estimation of the filling time and a more realizable details about the filling process. In practical engineering, the geometry of ship lock will be far more complex than here; the SIA is not enough to satisfy the demands for a desired design. The VOF method will be a nice choice and give reasonable predictions of filling time, water fluctuations and velocity fields in the ship lock.

Abstract: By using particle flow code (PFC2D), influence mechanism of isolation layer to granular media flow was studied by simulating two ore-drawing modes of filling mining method (working condition Ⅰ) and synchronous filling shrinkage method(working condition Ⅱ). After analyzed simulation results, some laws were gotten: (1) by the fitting process conducted on released volume and height, it is found that the relationship of released volume and height was power equation, which is same as the stochastic medium theory for ore-drawing; (2) The released volume, the size in most width of loosing body and the location of working condition Ⅱ was both bigger than those of working condition Ⅰ; (3) the radius of curvature of drawn-funnel of working conditionⅡ was bigger than those of working conditionⅠ, but the volume of residual ore was opposite. Analysis shows that the isolation layer reduced the contact force in ore drawing regional, made the porosity bigger, so as to improve liquidity. The results provide a theoretical reference for the changes in underground mining techniques and ore-drawing control.

Abstract: Hydraulic characteristics of orifice plates with multiple triangular holes in hydrodynamic cavitation reactor were experimentally investigated by use of three dimensional particle image velocimetry (PIV), high speed photography, electronic multi-pressure scanivalve and pressure data acquisition system, and numerically simulated by CFD software Flow 3D in this paper. Effects of number, arrangement and ratio of holes on hydraulic characteristics of the orifice plates were considered. Effects of arrangement and ratio of holes and flow velocity ahead of plate on cavitation number and velocity profile were compared. Distribution of turbulent kinetic energy and similarity of velocity profile were analyzed. And characteristics of cavitating flow downstream of the orifice plate were photographically observed by high speed camera. Also, a comparison with flow characteristics of orifice plate with hybrid holes (circle, square and triangle) was made.

Abstract: With regards to the characteristics of inter-basin water transfer projects, a 3d visual simulation (Three-Dimensional Visual Simulation, 3DVS) method for inter-basin water transfer project was proposed. A virtual reproduction of the entire project and its topography is achieved. The supplement of the three-dimensional topographic data was completed by Civil 3D combinedwith Google Earth. In this paper, the 3D digital model of inter-basin water transfer project is established using 3ds Max. Based on the established digital model, the simulation of channel water were realized .The Yuzhou section of South-to-North Water Transfer Project is taken as a case study. 3D visual simulation provides an effective way for the construction management and decision-making for inter-basin water diversion project.

Abstract: To explore the impact of changes in water quality of the Nanjing Inner Qinhuai River water system in different water diversion way and to assess the transfer effect, an one-dimensional hydrodynamic and water quality model for Inner Qinhuai River was established to simulate and analysis the responds of water quality on the different nutrient loading and different diverted water. Four different water discharges diverted from Xuanwu Lake and Exterior Qinhuai River and two loads including the present load and 50% reduction were considered. The result shows the water quality can be improved significantly only as enough water is diverted and the sewage is intercept in the Middle Reach of the Inner Qinhuai River.