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381.
阐述了新型SXD水力旋流沉淀器的工作原理及结构特点,并从理论和实际应用两方面分析了影响水力旋流器处理效果的因素,评价了其在精对苯二甲酸废水处理中的性能。 相似文献
382.
383.
Michael F. Merigliano 《Journal of the American Water Resources Association》1997,33(6):1327-1336
ABSTRACT: The at-a-station hydraulic geometry of stream channels can serve as a predictor of alluvial stream channel behavior. This geometry is the empirical relations describing changes in water surface width, mean depth, and mean velocity with changing discharge. The exponent values are correlated with channel morphology and behavior such as scour and fill, flow resistance, bank resistance, and competence. Channel behavior and morphology are apparently related, but some causes for effects are uncertain. Several studies, using empirical and theoretical bases, are reviewed here to illustrate the relation between hydraulic geometry and channel behavior, but the relations are not always consistent. Hydraulic geometry variables are easy to measure and readily available, but they do not always reflect what may be more important ones such as turbulence, the velocity distribution profile, and distribution and cohesion of sediment particles. This paper illustrates some of these problems, provides some solutions, and addresses need for more work to better predict stream channel behavior from hydraulic geometry 相似文献
384.
L. M. Risse B. Y. Liu M. A. Nearing 《Journal of the American Water Resources Association》1995,31(1):147-159
ABSTRACT: Since the trend in infiltration modeling is currently toward process-based approaches such as the Green-Ampt equation, more emphasis is being placed on methods of determining appropriate parameters for this approach. The SCS curve number method is an accepted and commonly used empirical approach for estimating surface runoff, and is based on numerous data from a variety of sources. The time and expense of calibrating process-based infiltration parameters to measured data are often prohibitive. This study uses curve number predictions of runoff to develop equations to estimate the “baseline” hydraulic conductivities (Kb) for use in the Green-Ampt equation. Curve number predictions of runoff were made for 43 soils. Kb values in the Water Erosion Prediction Project (WEPP) model were then calibrated so that the annual runoff predicted by WEPP was equal to the curve number predictions. These calibrated values were used to derive an equation that estimated Kb based on the percent sand, percent clay, and cation exchange capacity of the soil. Estimated values of Kb from this equation compared favorably with measured values and values calibrated to measured natural runoff plot data. WEPP predictions of runoff using both optimized and estimated values of Kb were compared to curve number predictions of runoff and the measured values. The WEPP predictions using the optimized values of Kb were the best in terms of both average error and model efficiency. WEPP predictions using estimated values of Kb were shown to be superior to predictions obtained from the curve number method. The runoff predictions all tended to be biased high for small events and low for larger events when compared to the measured data. Confidence intervals for runoff predictions on both an annual and event basis were also developed for the WEPP model. 相似文献
385.
Mariano Guardo Richard S. Tomasello 《Journal of the American Water Resources Association》1995,31(4):687-701
ABSTRACT: This paper describes the application of the SHEET2D model to the Florida's Everglades Nutrient Removal (ENR) Project. The ENR Project is a 3815 acre (1545 ha) pilot project, located in Palm Beach County. The operation of the treatment system will be used to demonstrate the performance of larger scale constructed wetland systems for removal of phosphorus from Everglades Agricultural Area (EAA) stormwater runoff. It is currently the largest stormwater wetland treatment system in the world. The SHEET2D model was used to analyze the performance of the ENR Project. SHEET2D is a two-dimensional, depth-averaged hydrodynamic model that is applicable to shallow water flow conditions. Subsequently, results from SHEET2D simulations were used to develop the ENEMOD model. ENRMOD is a lumped parameter box water quality model that can be used to analyze the long term performance of the ENR project with respect to hydrology and phosphorus uptake. Localized short-circuiting in the agricultural ditches within the project area was analyzed by using the RBFVM-2D model, which is a finite volume hydrodynamic model that is also applicable to shallow water flow conditions. The SHEET2D model was employed to simulate the hydraulics of the structures between cells and the hydrodynamics of the sheet-flow moving across the buffer cell and treatment cells. Collection, distribution, and larger discharge canals within the project were simulated by means of the MultiBasin Routing (MBR) model features that are built into the SHEET2D model. Constant inflows (75 to 600 cfs [2.1 to 17 m3/s]) were used in all runs to simulate the discharge of the ENR Project based on the proposed operating schedule for the outflow pump station. The model simulated 30 days to reach steady state conditions. Under steady state conditions, the hydraulic retention times were computed for the project and the split of flow between the two treatment trains of the entire project from the common buffer cell. Additionally, design components such as height of the levees, capacity of the structures, and hydrographs at specified grids were obtained. 相似文献
386.
S. J. Riley 《Journal of the American Water Resources Association》1978,14(1):1-11
ABSTRACT: While minimum variance theory appears to offer an explanation for the hydraulic behaviour and regularity among channel systems it is not entirely successful in predicting the regime of a channel system. In the case of the Namoi-Gwydir river system the hydraulic variables velocity, depth, width, slope, friction, and shear appear to govern the behaviour and, hence regime of the channels. The significance of sediment load in determining regime could not be assessed. 相似文献
387.
ABSTRACT: The National Regulatory Research Institute has recommended the merger of small rural water districts in the United States. Success at bringing about merger of these districts, which contain fewer than 3,500 customers, has been highly limited. The subject of this paper is a demonstration project that may act as a catalyst to achieve the desired goal of regionalization. A computerized hydraulic data management program (CHDMP) was developed for a case study in Nelson County, Kentucky. University professors, graduate students, and two water utilities’ staffs cooperated in network analysis employing computer hardware and software. The utilities’ staffs were taught the science and technology of hydraulic model preparation, simulation, and analysis for the case study distribution systems. As an integrated system, the model contained 294 pipes, 234 nodes, six pumps, and 11 tanks. Each utility's problem areas were identified and some of the individual and mutual benefits of hydraulic planning were illustrated. A dialogue resulted between the managers. Each manager described his goals and agreed that, although political merger was not feasible at the present time, future economic factors could be a definite influence in reversing that decision. 相似文献
388.
389.
本文介绍了二氧化碳致裂技术的主要装置特点及其工作原理,并以152掘进巷道作为主要的研究对象,针对巷道的掘进消突中二氧化碳致裂技术的应用进行探讨。结果表明:基于二氧化碳气体相变原理致裂爆破技术方式,在致裂期间不会产生火花,同时具有运输安全和操作方便等优点,有利于降低安全风险,提升煤矿的安全生产水平。 相似文献
390.
采用硬化河道水力跌水复氧小试装置,研究了跌水高度、跌水流量、跌水深度、进水DO浓度等因素对硬化河道水力跌水复氧效果的影响。试验结果表明,跌水高度为0.6 m条件下水力跌水对硬化河道水体的复氧效果,优于跌水高度为0.2 m和0.4 m时的复氧效果;跌水流量为150 L/h条件下水力跌水复氧效果,优于跌水流量为50 L/h和100 L/h时的复氧效果;跌水深度为0.4 m条件下水力跌水复氧效果优于跌水深度为0.2 m时的复氧效果。水力跌水措施对硬化河道水体的复氧效果整体上与跌水高度、跌水流量、跌水深度呈正相关,与进水DO浓度呈负相关。 相似文献