Applied Mechanics and Materials Vols. 744-746

Abstract: Navigation task of water conservancy when the over-current buildings are in runtime often affect the flow regime lock approach, endangers the ship navigation safety. In engineering we often set up guide wall protection approaches between approaches and flow buildings. By means of numerical simulation, the guide wall shape optimization study, and combining with the engineering practice, this paper proposes a microbend flood guide wall of new type. The results show that this new type of guide wall can in a variety of flow circumstances change such flow structure, reduce the horizontal speed of the approaches, is a simple and effective engineering measures.

Abstract: A one-dimensional numerical model was developed for unsteady-flow in a large-scale conveyance channel with complex inner boundary conditions. Using Taylor expansion and finite difference method, this model incorporated three types of inner boundary conditions, including regulators, inverted siphons, and flumes with parallel connections. It can facilitate continuous simulation with large-amplitude variations in water level and flow discharge during the flow transitions. Transition flows were simulated by this model, which were caused by the operation of a single gate of the Middle Route of the South-to-North Water Diversion Project. The discharges of simulation were consistent with the discharges of formulas calculation, and the water level variations accords with hydraulic law. The results indicate its efficiency and applicability on simulating hydraulic response of large-scale conveyance channels with complex inner boundary conditions.

Abstract: Taking Derisubaoleng Reservoir as an example, the experiment is mainly based on physical model and numerical simulation to study the effect of sediment control and discharge of the sediment retaining weir. With the help of the reservoir terrain a sediment retaining weir is built to form a“ deputy reservoir” ,which makes the sediment passing road more narrow, As a result, the ability of sluicing sediment is stronger than before. The purpose of this paper is to search a new idea to solve sediment problem in lake-type reservoir on sediment-laden river. The study result indicates that the sediment retaining weir both can prevent sediment being deposited in north “deputy reservoir” and can enhance the ability of sediment discharge in south “main reservoir” . Thus ,the sediment retaining weir is a effective engineering measure to solve sediment problem in lake-type reservoir.

Abstract: This experiment used SODO^TM ozone catalytic oxidation technology treated MBR effluent of a advanced treatment project of water treatment company in pilot scale test, which studied the effect of SODO^TM oxidation and resolved the problem of MBR effluent drainage system can not meet the standards of "Discharge standard of pollutants for municipal wastewater treatment plant " (GB18918-2002). Operating parameters of the test device: Ozone dosage was 200mg/L•h, system contact oxidation time was 4h, the average of effluent COD_Cr was about 100mg/L by controlled the dosage and other parameters at the economical operating conditions.

Abstract: ANSYS is an engineering analysis software with a multiple analysis ability.It can be used to solve the structure, fluid, electric, electromagnetic fields and collision problems and so on.So it has been widely used in varied fields.Circular culvert is commonly used for water hydraulic structure in hydraulic engineering.The paper focuses on the study of culvert soil pressure at the top of the circle under the sand in the northern of China by using the Ansys finite element analysis software.Research shows that:When the elastic modulus and Poisson's ratio changes,the soil pressure distribution shape doesn’t obviously change;While the soil pressure and the relative height of precipitation have a certain relationship with the two indicators.

Abstract: It is incapable for current method to establish the diversion standard when two hydropower stations are constructed synchronously. Hence this paper studied it from the perspective of harmonious allocation with considering the balance between economy and safety. Firstly, the risk estimation model of each diversion system under such condition was established in which the composition theory of regional flood was introduced to calculate the changed flood and the Copula function was adopted to construct its probability distribution. On this basis, with treating the adjacent diversion system as a whole, the allocation model of the diversion standard was established in which the life cycle cost (LCC) was proposed as the evaluation index. Aimed at the minimum of the LCC of the serial diversion system, the optimum diversion standard combination was ascertained. Finally, an engineering case was presented to validate the feasibility and effectiveness of the proposed model. And the study can offer the theoretical basis and technical reference for the control of the construction flood in the development of the cascade hydropower station.

Abstract: In order to research the influence rule of the spacing distance between orifice plates to the local resistance coefficient and total local water head losses , carried out the experiment research through set the two different relative distance of orifice plates in the pressure delivery pipeline. The experimental results showed that: When the relative distance, the results of total local water head losses calculated by the traditional hydraulics formula with the real measured data, the maximal relative error was less than 3%. This shown that when the relative distance was big, it was no necessary to consider the influence of the relative distance between orifice plates. However, when the relative distance, the real measured data of the total local water losses was much smaller than the calculated data by the traditional calculation formula, the maximal relative error was reached 239.5%. It was explained that when the relative distance was relative small, existed the adjoining influence between orifice plates, so the total local water losses by the multi-orifice plates was not equal to the sum of each water head loss by the single orifice plate, and the total local head loss was not necessarily increased with the number of orifice plates increasing. Whether or not the increasing total local water head losses was closely related with the relative distance of the orifice plates. The traditional local water head loss calculation formula in the hydraulics should be corrected and modified.

Abstract: As a long-term source of contaminant solutes, the flow of water within a waste rock pile containing reactive sulfide minerals significantly contributes to the solutes transportation. In this paper, a waste rock pile with the internal structures and grain size distribution from a typical waste dump is introduced as the geometric configuration. A numerical model is then applied to simulate unsaturated flow within a waste rock pile constructed with two primary materials. The simulations results show that the water movement within heterogeneous pile mainly depended on the internal structures. The flow of water can be controlled by the fine material layers within the coarse materials. These fine material layers form a capillary barrier which preventing the water infiltrate towards the centre of the pile. They can retain more water than coarse materials and form a ponding effect and/or percolation points within the pile.

Abstract: This paper study on PAC-UF process for treatment of micro surface polluted water, found that PAC-UF process can effectively remove 83% COD_cr, 55% NH₃-N and 81% UV₂₅₄, it shown that PAC-UF process had good treatment effect to micro surface polluted water, thus adding PAC can improve the treatment effect and alleviate membrane fouling. The material and influence of hydrophobic were analyzed and found that PVDF membrane had better performance.

Abstract: In this study, infiltration experiment and survey on specific penetration resistance for the topsoil were conducted for five land use patterns at the Liudaogou Catchment on the northern Loess Plateau. A simple infiltration model has been developed based on water balance principle combined with theory of steady infiltration. The mean unsaturated infiltration rate of topsoil was estimated based on the results of infiltration experiment and survey on specific penetration resistance combined with model calculation. The results indicated that determination coefficient of relation curve between mean unsaturated infiltration rate and the topsoil specific penetration resistance is higher than 0.93; order of the mean unsaturated infiltration rate of topsoil was 10-5 m/s during the research period; sequence of the mean unsaturated infiltration rate of the five land use patterns is Alfalfa (on slope land) < Grassland (on slope land) < Grassland (on alluvial plain) < Farmland (on alluvial plain) < Sandy loess (bare land); mean unsaturated infiltration rate of alfalfa (on slope land) and grassland (on slope land) was obviously lower than that of the mean of the five land use patterns, and mean unsaturated infiltration rate of sandy loess (bare land) was significantly higher than that of the mean of the five land use patterns.