Most of the large dams designed with complicated geometry in which physical models have been used extensively. Overflow design guidelines has been used for standard geometries, which are fairly simple. For more complex geometries, physical and numerical models studied here was helpful. The disadvantages with the physical models are high costs and that it can take fairly long time to get the results. In this paper we used a numeric method that is called volume of fluid (VOF) to calculate flow rates on three types of ogee spillways. The results were compared and these comparisons showed good proximity between numeric and experimental data. Results provided information on how accurately a commercially available computational fluid dynamic CFD model can predict the spillway flow rate. Ogee shape spillway was used to control the height and volume of water behind the dam. Geometrical properties affected hydraulic variables were investigated. The most common overflow hydraulic structure was analyzed for considering its optimal safety, cost of operation and maintenance. Based on analysis, geometry, the flow rate and construction cost was sensitive and affected hydraulic properties of the system. A numerical method volume of fluid (VOF) was considered for computational analysis of geometry and hydraulics variables for three types of spillways. Numerical results were compared with experimental observations and measurements provided verification of the model and coding performances. The comparison showed that numerical modeling were enhanced and accurately predicted the multi-variables and objective functions involved in a complicated hydraulic structure operation. Key words: Shape of spillway, numerical method, volume of fluid, optimized fl... ... middle of paper ... ...stem. Authors found this topic as an important subject of critical flow conditions in water resources systems analysis and design. Importance of engineering implementation and maintenance is considered. Spillway types used in this study In this study three types of spillway were used. Type I has low radius of curvature, type II has medium radius of curvature and type III has high radius of curvature. Three types of spillway are selected to investigate the geometry effects on discharge flow rates. In 2001 Savege & Johnson worked on type II numerically and experimentally and in this case their results are used [9]. Type I has low radius of curvature and needs less materials. So type II cheaper than others. But type II has high curvature and needs more materials and will be most expensive. In Table 1, three types of spillway and its height design (Hd) are presented.
There are three dams directly on the Genesee River, one at the south end of the park and two at the north end (Fish, n.d.). According to the Fish and Wildlife Service, the dam at the south end of the park is the Portageville Dam, which was built for irrigation and affects 45.16 miles of river. The Portageville Dam is not documented on the cu...
Grand Coulee Dam is a hydroelectric gravity dam on the Columbia River in Washington State, built by industrialist Henry J. Kaiser It is among the most famous dams in the United States. The reservoir it created is called the Franklin Delano Roosevelt Lake. The reservoir is named after the United States President who seemed to love dams and hydroelectric power and who was involved with the project through to the final completion of the dam. The dam was built as part of the Columbia Basin Project as a way to irrigate the desert areas of the Northwest United States. The dam started during the 1930s as a public works project and finished toward the beginning of World War Two. The initial construction plan was reconfigured during construction for more height. Its height was determined by the point at which the water from the reservoir began backing up into Canada. The scope and size of the dam is hard to comprehend. It is over a mile long and taller than the Great Pyramid of Giza, in fact, all the pyramids at Giza can fit within the base of the Grand Coulee Dam. The dam is so large that a truck at the base looks like a toy, this creates some perspective into the dam's true size. When the dam was completed in the early 1940s it was the largest dam in the world.
In the 1898 mayoral election, Frederick Eaton was elected as mayor of Los Angeles; and appointed his associate, William Mulholland- the superintendent of the newly created Los Angeles Department of Water and Power. Eaton and Mulholland envisioned a region of Los Angeles that would make Los Angeles become the turn of the century. The limiting factor of that regions growth was water supply. Eaton and Mulholland realized that the Owens Valley had a large amount of runoff from the Sierra Nevada, and a gravity-fed aqueduct that could deliver the Owens water to Los Angeles. During the early 1900’s the United States Bureau of Reclamation made plans to build an irrigation system to help the farmers of the Owens Valley. By 1905, through purchases, and alleged intimidation and bribery, Los Angeles purchased enough water rights to enable construction of the aqueduct.
Over the years Glen Canyon Dam has been the spark for hundreds of debates, rallies, and protests. These debates have been going on for almost forty years now. The fact is that the dam created a huge lake when it was built, this is what bothers environmentalists. This lake is called Lake Powell and thousands of people depend on its tourists for income. The lake also filled up a canyon called Glen Canyon, some people say it was the most beautiful place on earth. The anti-dam side of the debate has its basis in the fact that Lake Powell is currently covering Glen Canyon. It was very remote so few people got to witness its splendor. This is probably the reason the dam was built in the first place, ignorance.
Based on the events that lead to the devastating floods in Queensland and the eventual case that was brought against the engineers of the dam, there have been views from both sides of the divide as to whether or not the actions taken by the engineers were actually ethical or otherwise. We have explored this avenue and have found that both sides of the divide have good reasons to justify their actions. Firstly, we shall explore the avenue that the engineers decisions were appropriate and ethical. It can be said that the engineers did employ act utilitarianism in their decisions and actions, hence causing these decisions to be ethically correct. Act utilitarianism is essentially doing the right thing, which would benefit the majority of people, based on the situation that is currently taking place. One of the reasons that explains why the actions taken could be considered as ethically fine, was that if the dam was not opened, there would have been no other way to solve the increasing water levels in the dam. If no action was taken, there could have been seriously devastating effects, like the dam wall eroding due to water spilling over the dam wall, thus weakening the structure, or a loss of water flow control. Professor Hubert Chanson, a professor in hydraulic engineering in the University of Queensland, mentioned that the Wivenhoe Dam was actually designed as an embankment dam, hence it should not be overtopped, that is water should not be allowed to flow over the limits of the dam (Andersen 2011). Despite there being a secondary spillway, however it is recommended that spillway is not put to use, as the use of that spillway would mean that there would be a surge of water leaving the dam, and a loss of control of the water flow, w...
The dam itself spanned a gap of 918 feet across the valley and was 72 feet high. The primary materials used for the dam were rock and other earth. The dam started as 10 feet thick at the top of the structure and expanded to 220 feet at the base (NPS). As you can see in the image below of the dam there is a culvert that runs under the dam that was used to discharge water in the South Fork Creek that was then sent to a local canal. The flow of water was controlled by five 2ft diameter cast iron valves that were located in the tower to the left of the structure. In the event of an emergency were the culvert couldn't handle a large quantity of water an 85 ft wide spill-way was cut through the solid rock of the hillside near the eastern end of the dam (Jackson, Donald Dale).
In the late 1800’s and early 1900’s, John Muir, a naturalist, and Marsden Manson, an engineer for the city of San Francisco, engaged in a heated debate over the construction of a dam in Hetchy Hetchy Valley. Muir wanted to preserve nature for the future, so he objected to the dam because he felt it would destroy the beauty of the area. On the other hand, Manson believed building a dam would provide water and electricity to the thousands of people who lived in the city of San Francisco, and this would preserve the well being of the human race for the future. Both men had good points and arguments to support their views; however, in the end you have to look out for your own kind. If there is a choice about the well being of the human race or nature, I believe there is only once choice to be made – the future support of the human race.
A large issue we have that effects multiple different areas of our communities, are tragedy of the commons, which are actions that are rational but lead to irrational outcome. Government needs to take responsilbities to enforce rules for commons so they can diminish tragedy of the commons. Dams are a tragedy of the commons that only recently were come to the realisation of its more negatives effect they have on our world. Dams used to be seen as only positive, for their productful factors such as hydroelectricity and water supply. In this essay, I will argue that dams are an example of a tragedy of the commons proven by the documentary, Damnation, by the directors Travis Rummel and Ben Knight by describing that dams are highly subtractable
Never before has a dam of such magnitude ever been attempted in the world. The Three Gorges Dam will stretch 2-kilometers (1.3 miles) across the Yangtze River, tower 185 meters into the air (610 feet), and create a 600-kilometer (385 miles) reservoir behind it (Probe International). It will also be the most costly dam ever built once, and if, it is completed. "Estimated costs of...
Question: Discuss the importance of Relief Valves in the unit operations in detail, and give the design criteria/ parameters/ models available equations in the literature. Support your work by giving a typical example from the literature.
Wuerthner, George. North Idaho's Lake Country. Helena, MT: American & World Geographic Pub., 1995. Print.
Ubilla, Javier, Tarek Abdoun, Inthuorn Sasanakul, Michael Sharp, Scott Steedman, Wipawi Vanadit-Ellis, and Thomas Zimmie. "New Orleans Levee System Performance during Hurricane Katrina: London Avenue and Orleans Canal South." Geotechnical & Geoenvironmental Engineering (2008): n. pag. Academic Search Premier. Web. 12 Dec. 2013.
Grand Canyon Dam, moreover called Hualapai Dam, was a proposed dam in the lower Grand Canyon of the Colorado River, in northern Arizona in the United States. It would have been arranged close Bridge Canyon Rapids in a to an extraordinary degree extreme and disengaged bit of the chasm, 235 miles (378 km) downstream of Lee's Ferry and at the most noteworthy end of Lake Mead. At first proposed in the 1920s, the endeavor was really considered by the U.S. Power of Reclamation for a period of more than a quarter century the mid-1950s to 1968. In case collected, the dam would have stood 740 feet (230 m) high, molding a store broadening more than ninety miles (150 km) upstream, including thirteen miles (21 km) along the edge of Grand Canyon National
This chart shows the relationship between the fanning friction factor and the Reynolds number over a wide range of flow rates, from which the roughness parameter (e/D) for the piping system can be estimated.
A Flood Hydrograph and the Factors That Affect its Form A flood hydrograph is a graph of two axis, 'discharge' and 'time'. Plotted on the graph is the amount of discharge over a period of time. By looking at a hydrograph, a lot of information and data can be gathered about the river, the precipitation, the surrounding area and vegetation etc. The gradient, height and length of a line can tell you a lot of this information. There are many different factors that can affect the appearance and shape of a hydrograph.