The Francis turbine is a type of water turbine . It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency.
63-625: San Luis Dam , also known as B.F. Sisk Dam , is a major earth-filled dam in Merced County, California , which forms San Luis Reservoir , the largest off-stream reservoir in the United States . The dam and reservoir are located in the Diablo Range to the east of Pacheco Pass and about 10 miles (16 km) west of Los Banos . San Luis Dam, a jointly-owned state and federal facility, stores more than 2 million acre feet (2.5 km) of water for
126-413: A bellwether county for presidential elections. Since 1916 , it has voted for the winner in each election except in 1956 when it voted for Adlai Stevenson II instead of Dwight D. Eisenhower , 1968 when it voted for Hubert Humphrey instead of Richard Nixon , and 2016 when it voted for Hillary Clinton instead of Donald Trump . In 2024 , Donald Trump won the county in a slim victory, continuing
189-471: A female householder with no husband present, and 22.0% were non-families. 17.7% of all households were made up of individuals, and 7.4% had someone living alone who was 65 years of age or older. The average household size was 3.25 and the average family size was 3.69. In the county, the population was spread out, with 34.5% under the age of 18, 10.3% from 18 to 24, 27.9% from 25 to 44, 17.8% from 45 to 64, and 9.5% who were 65 years of age or older. The median age
252-521: A majority in the county in both 2000 and 2004 . According to the California Secretary of State, as of October 20, 2008, there were 97,179 registered voters in Merced County. Of those, 44,704 (46.0%) are registered Democratic, 35,955 (37.0%) are registered Republican, 3,090 (3.2%) are registered with other political parties, and 13,430 (13.8%) declined to state a political party. Atwater and
315-850: A small reservoir located directly in front of San Luis Dam where the water is temporarily stored for distribution. Most CVP project water is dedicated to irrigation while the SWP water supply is split, with 30 percent going to agriculture and 70 percent to urban areas. The San Luis Pumping-Generating Plant (also known as the William R. Gianelli Power Plant) is situated between O'Neill and San Luis Reservoirs and can pump water uphill for storage in San Luis during period of low demand, and release it during periods of high demand. The plant has eight reversible Francis turbine units which can generate up to 424 megawatts when releasing water. The power consumption while pumping
378-428: A vertical shaft, to isolate water from the generator. This also facilitates installation and maintenance. Water wheels of different types have been used for more than 1,000 years to power mills of all types, but they were relatively inefficient. Nineteenth-century efficiency improvements of water turbines allowed them to replace nearly all water wheel applications and compete with steam engines wherever water power
441-436: A wide range of heads and flows. This versatility, along with their high efficiency, has made them the most widely used turbine in the world. Francis type units cover a head range from 40 to 600 m (130 to 2,000 ft), and their connected generator output power varies from just a few kilowatts up to 1000 MW. Large Francis turbines are individually designed for each site to operate with the given water flow and water head at
504-512: A year-round water supply, and began studies for this project in 1955. During the 1950s the State of California also began building its own water project, whose design also required an off-stream water storage reservoir. The state approached the federal government with an offer to design a joint-use facility; however it took several years for the Bureau of Reclamation to agree to the proposal. On May 16, 1960,
567-680: Is 376 megawatts. The maximum water flow while generating is 13,120 cubic feet per second (372 m/s), and maximum pumping is 11,000 cubic feet per second (310 m/s). The sale of peaking power lowers the overall cost of operating the State Water Project, particularly the giant electric pumps along the California Aqueduct. A short 230 kV power line heads eastward to deliver this electricity to Northern California 's electricity backbone, Path 15 . However, due to friction losses when pumping water uphill, only about 70 percent of
630-669: Is a county located in the northern San Joaquin Valley section of the Central Valley , in the U.S. state of California . As of the 2020 census , the population was 281,202. The county seat is Merced . The county is named after the Merced River . Merced County comprises the Merced, CA Metropolitan Statistical Area , which is included in the Modesto -Merced, CA Combined Statistical Area . It
693-404: Is a type of reaction turbine, a category of turbine in which the working fluid comes to the turbine under immense pressure and the energy is extracted by the turbine blades from the working fluid. A part of the energy is given up by the fluid because of pressure changes occurring on the blades of the turbine, quantified by the expression of degree of reaction , while the remaining part of the energy
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#1732859444804756-544: Is accomplished via a system of canals and pumping stations which divert water from the Delta and deliver it south to water users. The San Luis Dam, a zoned compacted earthfill structure, is one of the largest embankment dams in the United States, with a structural height of 382 feet (116 m), a length of 18,600 feet (5,700 m) and a structural volume of 77,656,000 cubic yards (59,372,000 m). When full, San Luis Reservoir
819-530: Is also used for urban and environmental uses. The dam was built between 1963 and 1968, and filled for the first time in 1969. It provides flexibility to the state water system by capturing, via pumps and canals, the wet season (November–April) runoff that would otherwise flow from the Sacramento–San Joaquin River Delta into the Pacific Ocean . It also generates hydroelectricity by releasing
882-472: Is equal to that at the inlet to the draft tube. Using the Euler turbine equation, E / m = e = V w1 U 1 , where e is the energy transfer to the rotor per unit mass of the fluid. From the inlet velocity triangle, and Therefore The loss of kinetic energy per unit mass at the outlet is V f2 /2 . Therefore, neglecting friction, the blade efficiency becomes i.e. Degree of reaction can be defined as
945-445: Is extracted by the volute casing of the turbine. At the exit, water acts on the spinning cup-shaped runner features, leaving at low velocity and low swirl with very little kinetic or potential energy left. The turbine's exit tube is shaped to help decelerate the water flow and recover the pressure. Usually the flow velocity (velocity perpendicular to the tangential direction) remains constant throughout, i.e. V f1 = V f2 and
1008-443: Is located along Highway 152. San Luis Reservoir is designed to capture excess runoff flowing out of the Sacramento–San Joaquin River Delta , the largest watershed of California, during the winter and spring rainy season so it can be used during the dry season. This water includes both natural river flows, and water that is evacuated from Shasta Lake , Lake Oroville , Folsom Lake and other reservoirs for flood control purposes. This
1071-643: Is located north of Fresno County and Fresno , and southeast of Santa Clara County and San Jose . The county derives its name from the Merced River , or El Río de Nuestra Señora de la Merced (River of Our Lady of Mercy), named in 1806 by an expedition headed by Gabriel Moraga , which came upon it at the end of a hot dusty ride on the El Camino Viejo across the San Joaquin Valley in Spanish colonial Las Californias Province. Between 1841 and 1844, during
1134-419: Is more than 300 feet (91 m) deep, covers 12,700 acres (5,100 ha), and contains 2,041,000 acre-feet (2.518 km) of water. The storage capacity of San Luis Reservoir is divided with 55 percent belonging to the state and 45 percent to the federal government. The Delta-Mendota Canal , originally built in 1951, carries irrigation water for the federal Central Valley Project (CVP) operated by
1197-455: Is necessary, as these are major parameters affecting power production. Draft tube : The draft tube is a conduit that connects the runner exit to the tail race where the water is discharged from the turbine. Its primary function is to reduce the velocity of discharged water to minimize the loss of kinetic energy at the outlet. This permits the turbine to be set above the tail water without appreciable drop of available head. The Francis turbine
1260-423: Is seen when the head height is between 100–300 metres (330–980 ft). Penstock diameters are between 1 and 10 m (3.3 and 32.8 ft). The speeds of different turbine units range from 70 to 1000 rpm . A wicket gate around the outside of the turbine's rotating runner controls the rate of water flow through the turbine for different power production rates. Francis turbines are usually mounted with
1323-539: Is to run California's water system based on good science, not intuition." In 2013, the Bureau of Reclamation proposed raising the BF Sisk Dam by 20 feet (6.1 m) to create about 130,000 acre-feet (160,000,000 m) of extra storage capacity. An expanded reservoir could store more water in wet years to compensate for less water being pumped in dry years due to environmental restrictions. The project would cost $ 360 million and would also involve seismic upgrades to protect
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#17328594448041386-645: The California State Water Project and the federal Central Valley Project . Although the dam is located in the valley of San Luis Creek , the majority of its water comes from man-made aqueducts which are supplied from other rivers in Northern California. San Luis provides water mainly for irrigation in the San Joaquin Valley , where it augments the supply for more than 1 million acres (400,000 ha) of agricultural land, although some water
1449-880: The Metropolitan Water District of Southern California (MWD) which is one of the primary providers of water for the Greater Los Angeles Area . This water reaches Southern California via the East and West Branches of the California Aqueduct. It also provides water for the Central Coast cities like San Luis Obispo and Santa Barbara via the Coastal Branch of the California Aqueduct. Local water agencies and irrigation districts are allowed to "bank" water in San Luis Reservoir for later use, by purchasing it during
1512-713: The Santa Clara Valley via the Pacheco Tunnel and Hollister Conduit, which travel under the Diablo Range. At the western end of the tunnel, the water is stored behind San Justo Dam , an earthfill dam completed in 1986. These facilities are all part of the San Felipe Division of the Central Valley Project. The San Luis & Delta-Mendota Water Authority represents the 29 federal water contractors served by
1575-636: The U.S. Bureau of Reclamation to supply San Joaquin Valley farms. The California Aqueduct was built in 1968 as part of the State Water Project (SWP), to deliver water to Los Angeles and other cities and farmlands in Southern California. Both canals begin at the Clifton Court Forebay near Tracy, California where the Jones and Banks Pumping Plants draw water from the Delta in order to deliver it south. The canals are linked to O'Neill Forebay ,
1638-625: The U.S. Census Bureau , the county has a total area of 1,979 square miles (5,130 km ), of which 1,935 square miles (5,010 km ) is land and 44 square miles (110 km ) (2.2%) is water. The 2010 United States Census reported that Merced County had a population of 255,793. The racial makeup of Merced County was 148,381 (58.0%) White , 9,926 (3.9%) African American , 3,473 (1.4%) Native American , 18,836 (7.4%) Asian , 583 (0.2%) Pacific Islander , 62,665 (24.5%) from other races , and 11,929 (4.7%) from two or more races. Hispanic or Latino of any race were 140,485 persons (54.9%). As of
1701-601: The United States House of Representatives , Merced County is in California's 13th congressional district , represented by Republican John Duarte . In the California State Legislature , Merced County is in the 27th Assembly District , represented by Democrat Esmeralda Soria , and the 14th Senate District , represented by Democrat Anna Caballero . Merced County has been somewhat of
1764-511: The census of 2000, there were 210,554 people, 63,815 households, and 49,775 families residing in the county. The population density was 109 people per square mile (42 people/km ). There were 68,373 housing units at an average density of 36 units per square mile (14 units/km ). The racial makeup of the county was 56.2% White , 3.8% Black or African American , 1.2% Native American , 6.8% Asian , 0.2% Pacific Islander , 26.1% from other races , and 5.7% from two or more races. 45.3% of
1827-608: The poverty line , including 28.4% of those under age 18 and 10.7% of those age 65 or over. As of 2008, according to the Lao Family Community, a nonprofit organization, about 8,000 Hmong lived in Merced County. Merced County is a California Constitution defined general law county and is governed by an elected Board of Supervisors. The Board consists of five members, elected by districts, who serve four-year staggered terms. The Merced County Sheriff's Office provides court protection, jail administration, and coroner service for
1890-542: The Delta into the Pacific instead of being pumped into San Luis Reservoir. In December 2016, Congress passed a bill allowing increased water pumping during times when fish are not at high risk. This generally allows more water to be stored at San Luis Reservoir. The bill requires daily monitoring of fish to ensure environmental laws are not violated, instead of relying on hard limits which may not match current conditions. California Senator Dianne Feinstein remarked that "the goal...
1953-603: The San Luis Unit, consisting of a combined 2,100,000-acre (850,000 ha) service area in the San Joaquin and Santa Clara Valleys. The Authority operates the Federally owned portion of the San Luis Reservoir and water supply infrastructure. Certain environmental restrictions have been in place since the 1990s to limit pumping during the spring Sacramento River chinook salmon run (March–April). Water pumping during certain times of
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2016-412: The area and greatly expanded the irrigated acreage. However, the lack of local water storage limited the system's flexibility. During the dry summer months when surface water was frequently unavailable, farmers pumped vast volumes of groundwater to irrigate their crops, considerably depleting the regional aquifer. The Bureau of Reclamation recognized the need for a large storage reservoir in order to provide
2079-586: The county include Castle Airport , Gustine Airport , and Los Banos Municipal Airport . The population ranking of the following table is based on the 2010 census of Merced County. † county seat School districts include: K-12: Secondary: Elementary: University of California Merced is in the county. The former Castle Air Force Base and the United States Penitentiary, Atwater are located in an unincorporated area near Atwater . Francis turbine The process of arriving at
2142-460: The county's bellwether county status. Trump 's win in Merced county made it one of eight counties to flip from Biden to Trump , as well as making Merced one of five counties to vote for the Republican presidential candidate for the first time since George W. Bush in 2004 . Democrat Barack Obama won a majority in the county in both 2008 and 2012. Before that, Republican George W. Bush won
2205-606: The county's unincorporated areas have Republican plurality registration advantages. All of the other cities and towns in the county have Democratic pluralities or majorities in voter registration. Merced County has seen a rightward tilt in recent years, voting "Yes" in the 2021 gubernatorial recall election despite voting for Governor Gavin Newsom by a margin of 4% in 2018 . The county then voted for Republican nominee Brian Dahle in 2022 over Newsom, as well as for all Republican nominees for statewide office. The following table includes
2268-699: The dam from earthquakes. The dam expansion is one of several major water projects that could be funded, in part, by a $ 2.7 billion bond measure approved by California voters in 2014. In 2023, the Department of the Interior and San Luis & Delta-Mendota Water Authority approved plans to raise the Dam by 10 feet to create 130,000 acre-feet of additional water storage. The $ 1 billion project is expected to be completed by 2032. Merced County, California Merced County ( / m ər ˈ s ɛ d / mər- SED )
2331-465: The dam itself was awarded to Morrison-Knudsen , Utah Construction & Mining Co. , and Brown & Root in 1963 for $ 85.9 million. Alfred M. Petrofsky held the role of chief engineer. Construction of San Luis Dam lasted from 1963 to early 1968. The dam was constructed in several zones with quarried local earth and rock averaging as much as 130,000 cubic yards (99,000 m) per day. The 100-ton Caterpillar dump trucks used during construction were, at
2394-414: The dam were completed by 1961 and the groundbreaking ceremony took place on August 18, 1962. In front of a crowd of 15,000 people, President John F. Kennedy and California Governor Pat Brown gave the signal to detonate the first explosive charges in the San Luis dam site. Work began the same month to reroute Pacheco Pass Highway (today's SR 152 ) around the future reservoir basin. The primary contract for
2457-406: The design of high-efficiency turbines to precisely match a site's water flow and pressure ( water head ). A Francis turbine consists of the following main parts: Spiral casing : The spiral casing around the runner of the turbine is known as the volute casing or scroll case. Throughout its length, it has numerous openings at regular intervals to allow the working fluid to impinge on the blades of
2520-532: The energy can be recouped when the water is discharged. The valley filled by the San Luis Reservoir was originally inhabited by the Yokuts people; during the early 19th century it was part of Rancho San Luis Gonzaga and small-scale agriculture began in the area, supplied by groundwater and canals from the San Joaquin River . The Central Valley Project was begun in the 1930s to provide an additional water supply to
2583-634: The entire county. It provides patrol, detective, and other police services for the unincorporated parts of the county. The main sheriff station and offices are at Merced. There are two sheriff's substations. A Grand Jury report in 2010 stated that the Sheriff processed 12,746 average jail bookings per year with an average daily jail population of 1,123. Municipal police departments in the county are: Merced, population 83,000; Los Banos, population 38,000; Atwater, population 30,000; Livingston, population 13,000; Gustine, population 6,000; Dos Palos, population 5,500. In
San Luis Dam - Misplaced Pages Continue
2646-436: The guide and stay vanes is to convert the pressure energy of the fluid into kinetic energy. It also serves to direct the flow at design angles to the runner blades. Runner blades : Runner blades are the heart of any turbine. These are the centers where the fluid strikes and the tangential force of the impact produces torque causing the shaft of the turbine to rotate. Close attention to design of blade angles at inlet and outlet
2709-506: The highest possible efficiency, typically over 90% (to 99% ). In contrast to the Pelton turbine , the Francis turbine operates at its best completely filled with water at all times. The turbine and the outlet channel may be placed lower than the lake or sea level outside, reducing the tendency for cavitation . In addition to electrical production , they may also be used for pumped storage , where
2772-467: The modern Francis runner design took from 1848 to approximately 1920. It became known as the Francis turbine around 1920, being named after British-American engineer James B. Francis who in 1848 created a new turbine design. Francis turbines are primarily used for producing electricity. The power output of the electric generators generally ranges from just a few kilowatts up to 1000 MW, though mini-hydro installations may be lower. The best performance
2835-560: The number of incidents reported and the rate per 1,000 persons for each type of offense. According to America's Labor Market Information System 2014 report, the companies with the largest employment in Merced are, in alphabetical order: Merced County grows 90% of California's sweet potato crop, due in part to the efforts of John Buttencourt Avila, called "the father of the sweet potato industry". Merced Regional Airport , located two miles (3.2 km) southwest of downtown Merced, provides passenger air service. General aviation airports in
2898-427: The period when Alta California was a territory of independent Mexico, four Mexican land grants were made in what became Merced County: Rancho Orestimba y Las Garzas , Rancho Panoche de San Juan y Los Carrisolitos , Rancho San Luis Gonzaga , and Rancho Sanjon de Santa Rita Merced County was formed in 1855 from parts of Mariposa County . Parts of its territory were given to Fresno County in 1856. According to
2961-410: The population were Hispanic or Latino of any race. 6.6% were of Portuguese and 6.0% German ancestry according to Census 2000 . 55.1% spoke English , 35.3% Spanish , 3.2% Hmong , 2.9% Portuguese and 1.0% Punjabi as their first language. There were 63,815 households, out of which 45.4% had children under the age of 18 living with them, 57.8% were married couples living together, 14.1% had
3024-468: The rainy season at lower prices when it is not immediately needed. Regulations only allow such carryover storage when San Luis is not full, since state and federal water takes priority. Once the reservoir fills, any carryover water that has not been used is effectively "lost", i.e. transferred to the CVP and SWP supplies. In addition to supplying the main CVP and SWP canals, San Luis Reservoir also supplies water to
3087-433: The ratio of pressure energy change in the blades to total energy change of the fluid. This means that it is a ratio indicating the fraction of total change in fluid pressure energy occurring in the blades of the turbine. The rest of the changes occur in the stator blades of the turbines and the volute casing as it has a varying cross-sectional area. For example, if the degree of reaction is given as 50%, that means that half of
3150-402: The reservoir was at a low level the dam was in no immediate danger of failure, however it could not be safely refilled until the damage was repaired. By August 1982, the area had been stabilized with 1,400,000 cubic yards (1,100,000 m) of additional fill (known as a "buttressing berm"), at a cost of $ 6.1 million. In July 1984 another crack appeared in the dam, but it soon stabilized. Most of
3213-400: The runner. These openings convert the pressure energy of the fluid into kinetic energy just before the fluid impinges on the blades. This maintains a constant velocity despite the fact that numerous openings have been provided for the fluid to enter the blades, as the cross-sectional area of this casing decreases uniformly along the circumference. Guide and stay vanes : The primary function of
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#17328594448043276-602: The same principles. S. B. Howd obtained a US patent in 1838 for a similar design. In 1848 James B. Francis , while working as head engineer of the Locks and Canals company in the water wheel-powered textile factory city of Lowell, Massachusetts , improved on these designs to create more efficient turbines. He applied scientific principles and testing methods to produce a very efficient turbine design. More importantly, his mathematical and graphical calculation methods improved turbine design and engineering. His analytical methods allowed
3339-403: The sea. The restrictions have led to frequent low water levels at San Luis Reservoir; in late summer 2016 it fell to 10 percent of capacity, the lowest since 1991. These restrictions have been criticized by water agencies as too stringent, especially when California is in a long-term drought. During winter 2016 at least 180,000 acre-feet (220,000,000 m) of water was allowed to drain from
3402-537: The state and the Bureau of Reclamation signed a "coordinated operation" agreement which laid out plans for the construction of joint-use facilities, including the San Luis Dam and Power Plant. The state government was to cover 55 percent of the cost with the federal government providing the rest. On June 3, 1960, President Dwight D. Eisenhower signed an act authorizing the San Luis Unit Project. Plans for
3465-544: The time, the largest in the US. The construction of the four water intake towers, each 284 feet (87 m) high, involved the first use of tower cranes in the US. The work force peaked at 2,304 in October 1965 and declined thereafter; in January 1968, with construction almost completed, the first water was delivered through the California Aqueduct to begin filling the giant reservoir. The dam
3528-876: The total energy change of the fluid is taking place in the rotor blades and the other half is occurring in the stator blades. If the degree of reaction is zero it means that the energy changes due to the rotor blades is zero, leading to a different turbine design called the Pelton Turbine . The second equality above holds, since discharge is radial in a Francis turbine. Now, putting in the value of 'e' from above and using V 1 2 − V f 2 2 = V f 1 2 cot α 2 {\displaystyle V_{1}^{2}-V_{f2}^{2}=V_{f1}^{2}\cot \alpha _{2}} (as V f 2 = V f 1 {\displaystyle V_{f2}=V_{f1}} ) Francis turbines may be designed for
3591-628: The water stored behind San Luis Dam is used for irrigation. The CVP share of the water is released down the Delta-Mendota Canal into the San Joaquin River, which provides water for 380,000 acres (150,000 ha) of farmland in the central part of the San Joaquin Valley. Parts of the CVP and SWP water supply the Westlands Water District of Fresno and Kings Counties, which irrigates up to 735,000 acres (297,000 ha) of land on
3654-474: The water when it is needed. However, it has indirectly impacted the environment by enabling increased water diversion from sensitive estuary regions. In recent years, a combination of drought and pumping restrictions enacted to protect endangered fish have contributed to low water levels at the San Luis Reservoir. The dam and reservoir are visible from the Romero Overlook Visitors Center, which
3717-702: The west side of the San Joaquin Valley. Prior to the construction of San Luis Dam and the joint use portion of the California Aqueduct (the San Luis Canal) this area depended entirely on groundwater. In 2016 the main crops grown here were almonds, tomatoes, pistachios and wheat. Most of the Westlands district consists of large corporate farms totaling hundreds if not thousands of acres. The SWP also provides more than 980,000 acre-feet (1.21 km) of water per year for farmers in Kern County. San Luis Reservoir stores water for
3780-426: The winter and early spring interferes with fish migration. The pumping changes the primary direction of water flow in the Delta from east–west to north–south, confusing the fish. Before San Luis Dam was built, most of the pumping from the Delta occurred during the summer when there is high demand for irrigation. The construction of San Luis Dam enabled the additional capture of winter flows that would otherwise be lost to
3843-411: Was 29 years. For every 100 females there were 99.3 males. For every 100 females age 18 and over, there were 96.6 males. The median income for a household in the county was $ 35,532, and the median income for a family was $ 38,009. Males had a median income of $ 31,721 versus $ 23,911 for females. The per capita income for the county was $ 14,257. About 16.9% of families and 21.7% of the population were below
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#17328594448043906-516: Was available. After electric generators were developed in the late 1800s, turbines were a natural source of generator power where potential hydropower sources existed. In 1826 the French engineer Benoit Fourneyron developed a high-efficiency (80%) outward-flow water turbine. Water was directed tangentially through the turbine runner, causing it to spin. Another French engineer, Jean-Victor Poncelet , designed an inward-flow turbine in about 1820 that used
3969-463: Was officially dedicated on April 20, 1968, by Secretary of the Interior Stewart L. Udall . On May 31, 1969, the San Luis Reservoir filled for the first time. In 1981, during low water conditions in San Luis Reservoir, a 1,100-foot (340 m) long segment of the upstream face of the dam partially collapsed, causing 400,000 cubic yards (310,000 m) of material to fall into the reservoir. Since
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