Laboratory tests were conducted to determine the head losses in wyes and manifolds of conventional type, both with and without an internal tie-rod at the theoretical centre of the wye. These wyes and manifolds, having 45°, 60° and 90° subtending angles of the wyes, were symmetrical about the longitudinal axis of the main pipe. The apparatus and method of testing used in the tests are described. The experiment spans a range of Reynold's numbers from 85,000 to 420,000 in the influent main pipe. The analysis of experimental data is based on the energy equation of Bernoulli for the one-dimensional condition. The results of the tests are given in both tabular and graphical form. It appears that the coefficient of the form loss (the ratio of the form loss of a wye or manifold to the velocity head in the main pipe) is a function of the proportional flow of water through the branches, the size of the tie-rod used and the subtending angle of the wye. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Tidal stream power generation offers the prospect of predictable, low-CO2 power at a number of locations around the UK and the world. Previous assessments of tidal energy resources have taken the form of desk studies based on simplified navigational data. Where numerical model data has been used it has been at too low a resolution to capture high velocity tidal flows constrained by coastal topography. Analytical solutions for maximum energy extraction in simple tidal channels have been produced, but they have not been extended to more complex open-boundary cases such as flow around headlands and islands. There is therefore a role for site-specific numerical modelling, which when validated, offers the twin advantages of a high-resolution picture of the resource and allowing simulation of momentum extraction within the model to take place. In order to parameterize the sub-grid-scale momentum extraction in such models, a new analytical model of the velocity reduction in a large array of tidal turbines has been derived. The model extends previous models of large wind turbine arrays and uses analogies with flow through submerged vegetation. It provides an equivalent added drag coefficient suitable for use in a 2-D coastal numerical model. A numerical model of the flows in the region of the Portland Bill headland has been produced, forced by tidal elevations at the free boundary. A site selection exercise was carried out for the Portland Bill location and an area of around 12 km2 was identified as having a high potential for development using mean cubed speed found through tidal analysis of model results without energy extraction. A large tidal stream generator array has also been simulated within the Portland Bill model—linked to the new model for momentum extraction—and was found to have a significant effect on the tidal parameters in the locality. This was the first time that a large tidal array has been simulated in a realistic coastal domain of large extent, with a parameterization that takes into account the interaction of the turbines with the rough-wall flow in the natural state. Results predict that there is a region downstream of the array extending approximately 5–10 km around the simulated tidal stream turbine array in which the tidal stream ellipse major axis is reduced by at least 5%. In the area of momentum extraction the principal semi-diurnal tidal stream ellipse major axis length was reduced by 10–15%.

North Dakota’s oil boom is aided by a new technology, fracking. But this technology implies large amounts of wastewater. The methods of dealing with this wastewater are now an issue. Currently, North Dakota locks it into deep injection wells in the Bakken formation. With the development of membrane technologies to treat wastewater, it may be feasible to treat the wastewater and reuse it. This study uses a mathematical programming model to minimize the total cost of dealing with wastewater using three methods - deep well injection, on-site treatment, and off-site treatment. The model results show it is cost-effective to use on-site and large capacity off-site treatment to treat the 20% of the wastewater that flows back within the first 30-60 days after a well is drilled.

This diploma thesis deals with the design of the hydraulic puller. Furthermore, the diploma thesis presents the analysis of possible design solutions. It includes processing the selected design of the hydraulic puller with parameters: maximum pushing force 50 kN, speed of work movement 0,05 m.s-1. The analysis by using finite element method (FEM) is made. The next part of thesis includes the design of hydraulic circuit of puller. In the last part of thesis there is the design for replacement of hydraulic puller by mechanical systems.

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Hydraulic steel structures (HSS) are key components of U.S. Army Corps of Engineers infrastructure and are subject to corrosive environments, unpredictable loadings, and extreme conditions. Corrosion can take many forms and can cause costly damage to HSS due to inadequate design of protective measures. There are numerous forms of corrosion that have a negative effect on HSS, as well as material properties that need consideration when design HSS preventive measures. Understanding corrosion and providing proper preventive measures is crucial for HSS. Proper maintenance and repair of these protection systems also play a significant part in corrosion control of HSS.

<p> The continuous control of hydraulic pressure as a predetermined function of an independent variable is considered for the cases of low, intermediate and high pressure levels. A simple control system for the continuous regulation of low pressure is briefly discussed, and a means of extending its working range to intermediate pressure levels is described. Systems of this type are particularly suitable for the control of commercial diamond synthesis presses, but may also be utilised for other processes.</p> <p> A more sophisticated approach to problems of pressure generation and control is discussed in detail, with particular reference to a high pressure isostatic press. Digital computer methods of optimising the parameters of the system and simulating its response are developed.</p> / Thesis / Master of Engineering (ME)

The hydraulic analysis of culverts is complicated when using hand calculations. Fortunately, several computer programs are available to assist in analyzing culvert hydraulics, some of which include HY-8, Fish X-ing, Broken-back Culvert Analysis Program (BCAP), Hydraflow Express, Culvert Master, Culvert, and Hydrologic Engineering Center River Analysis System (HEC-RAS). While all of these programs can simulate the behavior of flow through a culvert, slightly different methodologies are utilized among the programs to complete a full hydraulic analysis, resulting in different predictions for headwater depth, flow control, and outlet velocities. The purpose of this paper is to compare (1) the available hydraulic features and (2) the numerical solutions from the seven programs to manually computed values. Four test cases were developed to test the accuracy of program results. The headwater depths and outlet velocities were compared to those obtained through calculations based on culvert hydraulic theory outlined in the Federal Highway Administration publication, Hydraulic Design Series 5. Based on the results, Fish X-ing was unable to analyze culverts under inlet control, while Culvert incorrectly predicted inlet control headwater depths at low flow conditions. Hydraflow Express struggled to predict correct outlet control headwater depths while BCAP had difficulty analyzing straight barrel culverts acting under outlet control. Overall, HY-8, Culvert Master, and HEC-RAS produced accurate results most consistently.

Hydraulic structures with water level differences between upstream and downstream are subjected to seepage in foundation soils. Two sources of weakness are to be guarded against: (1) percolation or seepage may cause under-mining, resulting in the collapse of the whole structure, and (2) the floor of the apron may be forced upwards, owing to the upward pressure of water seeping through pervious soil under the structure. Many earlier failures of hydraulic structures have been reported due to these two reasons. The curves and charts prepared by Khosla, Bose, and Taylor still form the basis for the determination of uplift pressure and exit gradient for weir apron founded on pervious soil of infinite depth. However, in actual practice, the pervious medium may be of finite depth owing to the occurrence of a clay seam or hard strata at shallow depths in the river basin. Also, a general case of weir profile may consist of cutoffs, at the two ends of the weir apron. In addition to the cutoffs, pervious aprons are also provided at the downstream end in the form of (i) inverted filter, and (ii) launching apron. These pervious aprons may have a thickness of 2 to 5. In order to accommodate this thickness, the bed adjacent to the downstream side of downstream cutoff has to be excavated. This gives rise to the formation of step at the downstream end. Closed form theoretical solutions for the case of finite depth seepage below weir aprons with end cutoffs, with a step at the downstream side are obtained in this research. The parameters studied are : (i) finite depth of pervious medium, (ii) two cut offs at the ends, and (iii) a step at the downstream end. iv The resulting implicit equations, containing elliptic integrals of first and third kind, have been used to obtain various seepage characteristics. The results have been compared with existing solutions for some known boundary conditions. Design curves for uplift pressure at key points, exit gradient factor and seepage discharge factor have been presented in terms of nondimensional floor profile ratios. Publications resulting from the dissertation are: 1. Jain, Arun K. and Reddi, L. N. “Finite depth seepage below flat aprons with equal end cutoffs.” (Submitted to Journal of Hydraulic Engineering, ASCE, and reviewed). 2. Jain, Arun K. and Reddi, L. N. “Seepage below flat apron with end cutoffs founded on pervious medium of finite depth.” (Submitted to Journal of Irrigation & Drainage Engineering, ASCE). 3. Jain, Arun K. and Reddi, L. N. “Closed form theoretical solution for finite depth seepage below flat apron with equal end cutoffs and a downstream step.” (Submitted to Journal of Hydrologic Engineering, ASCE). 4. Jain, Arun K. and Reddi, L. N. “Closed form theoretical solution for finite depth seepage below flat apron with end cutoffs and a downstream step.” (Submitted to Journal of Engineering Mechanics, ASCE).

A model was developed to simulate the groundwater of 8,300 acres of the Northern Cities Management Area (NCMA), which encompasses the northern portion of the Arroyo Grande Watershed and a small subset of the Santa Maria Valley Groundwater Basin. This watershed and groundwater basin is located on the coast and contains Oceano and the Cities of Arroyo Grande, Grover Beach, Pismo Beach. Groundwater in the NCMA is used heavily for agricultural irrigation in the southern portion and municipal applications in the northern portion. Up to 18 of these municipal wells and over 50 irrigation wells are drawing groundwater at any time. Due to the critical nature of both uses, and location on the coastline, both supply and quality is a significant concern. The objective of this research was to improve an existing groundwater model with a longer model duration, a more detailed and discretized recharge estimation, and incorporation of addition municipal well data. Some data was preprocessed in ArcMap. Groundwater modeling was accomplished with Aquaveo GMS using MODFLOW-NWT upstream weighting package (UPW). Elevation, hydrologic soil conditions, stream gauge heights and flows, recharge rates, fault locations, well locations and pumping rates, and transient head boundaries were created via coverages in GMS and mapped to MODFLOW. The model was calibrated using Parameter Estimation (PEST) with Singular Value Decomposition-Assist (SVD-Assist) to observation data in six select monitoring wells and fifteen Sentry wells. The model showed outflow from the domain to the ocean with groundwater flows shifting to parallel the coast following dry periods and significant simulated drawdown from one particular municipal well. These trends can provide water purveyors in the area with additional information on groundwater trends and effects of pumping rates on formation drawdown.