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Evolution From Francis Turbine To Kaplan Turbine
Francis turbine converts energy at high pressure heads which are not easily available and hence a turbine was required to convert the energy at low pressure heads, given that the quantity of water was large enough. It was easy to convert high pressure heads to power easily but difficult to do so for low pressure heads. Therefore, an evolution took place that converted the Francis turbine to Kaplan turbine, which generated power at even low pressure heads efficiently. Changes Turbines are sometimes differentiated on the basis of the type of inlet flow, whether the inlet velocity is in axial direction, radial direction or a combination of both. Francis turbine is a mixed hydraulic turbine (the inlet velocity has Radial and Tangential Components) while the Kaplan turbine is an Axial hydraulic turbine(the inlet velocity has only Axial Velocity Component). The evolution consisted of the change in the inlet flow mainly. Nomenclature of a Velocity Triangle: A general velocity trian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francis Turbine
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. The process of arriving at 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 is seen when the head height is between . Penstock diameters are between . 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 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Speed
Specific speed ''N''''s'', is used to characterize turbomachinery speed. Common commercial and industrial practices use dimensioned versions which are of equal utility. Specific speed is most commonly used in pump applications to define the suction specific speed€”a quasi Dimensionless quantity, non-dimensional number that categorizes pump impellers as to their type and proportions. In Imperial units it is defined as the speed in revolutions per minute at which a geometrically similar impeller would operate if it were of such a size as to deliver one gallon per minute against one foot of hydraulic head. In metric units flow may be in l/s or m³/s and head in m, and care must be taken to state the units used. Performance is defined as the ratio of the pump or turbine against a reference pump or turbine, which divides the actual performance figure to provide a unitless figure of merit. The resulting figure would more descriptively be called the "ideal-reference-device-specific pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Turbines
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, they are mostly used for electric power generation. Water turbines are mostly found in dams to generate electric power from water potential energy. History Water wheels have been used for hundreds of years for industrial power. Their main shortcoming is size, which limits the flow rate and head that can be harnessed. The migration from water wheels to modern turbines took about one hundred years. Development occurred during the Industrial revolution, using scientific principles and methods. They also made extensive use of new materials and manufacturing methods developed at the time. Swirl The word turbine was introduced by the French engineer Claude Burdin in the early 19th century and is derived from the Greek word "Ï„ÏÏβη" f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-dimensional Losses And Correlation In Turbomachinery
Three-dimension losses and correlation in turbomachinery refers to the measurement of flow-fields in three dimensions, where measuring the loss of smoothness of flow, and resulting inefficiencies, becomes difficult, unlike two-dimensional losses where mathematical complexity is substantially less. Three-dimensionality takes into account large pressure gradients in every direction, design/curvature of blades, shock waves, heat transfer, cavitation, and viscous effects, which generate secondary flow, vortices, tip leakage vortices, and other effects that interrupt smooth flow and cause loss of efficiency. Viscous effects in turbomachinery block flow by the formation of viscous layers around blade profiles, which affects pressure rise and fall and reduces the effective area of a flow field. Interaction between these effects increases rotor instability and decreases the efficiency of turbomachinery. In calculating three-dimensional losses, every element affecting a flow path is taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velocity Triangle
In turbomachinery, a velocity triangle or a velocity diagram is a triangle representing the various components of velocities of the working fluid in a turbomachine. Velocity triangles may be drawn for both the inlet and outlet sections of any turbomachine. The vector nature of velocity is utilized in the triangles, and the most basic form of a velocity triangle consists of the tangential velocity, the absolute velocity and the relative velocity of the fluid making up three sides of the triangle. Velocities involved A general velocity triangle consists of the following vectors: *''V'' : Absolute velocity of the fluid. *''U'' : Blade Linear velocity. *''Vr'': Relative velocity of the fluid after contact with rotor Rotor may refer to: Science and technology Engineering *Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator * Helicopter rotor, the rotary wing(s) of a rotorcraft .... *''Vw'': Tangential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impeller
An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating component of a centrifugal pump that accelerates fluid outward from the center of rotation, thus transferring energy from the motor that drives the pump to the fluid being pumped. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. An impeller is usually a short cylinder with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or threaded bore to accept a drive shaft. It can be cheaper to cast an impeller and its spindle as one piece, rather than separately. This combination is sometimes referred to simply as the "rotor." Types Open impellers An open impeller has a hub with attached vanes and is mounted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runner
Running is a method of terrestrial locomotion allowing humans and other animals to move rapidly on foot. Running is a type of gait characterized by an aerial phase in which all feet are above the ground (though there are exceptions). This is in contrast to walking, where one foot is always in contact with the ground, the legs are kept mostly straight and the center of gravity vaults over the stance leg or legs in an inverted pendulum fashion.Biewener, A. A. 2003. Animal Locomotion. Oxford University Press, US. books.google.com/ref> A feature of a running body from the viewpoint of spring-mass mechanics is that changes in kinetic and potential energy within a stride occur simultaneously, with energy storage accomplished by springy tendons and passive muscle elasticity. The term running can refer to any of a variety of speeds ranging from jogging to sprinting. Running in humans is associated with improved health and life expectancy. It is assumed that the ancestors of humankin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impeller
An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating component of a centrifugal pump that accelerates fluid outward from the center of rotation, thus transferring energy from the motor that drives the pump to the fluid being pumped. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. An impeller is usually a short cylinder with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or threaded bore to accept a drive shaft. It can be cheaper to cast an impeller and its spindle as one piece, rather than separately. This combination is sometimes referred to simply as the "rotor." Types Open impellers An open impeller has a hub with attached vanes and is mounted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Velocity
In continuum mechanics the flow velocity in fluid dynamics, also macroscopic velocity in statistical mechanics, or drift velocity in electromagnetism, is a vector field used to mathematically describe the motion of a continuum. The length of the flow velocity vector is the flow speed and is a scalar. It is also called velocity field; when evaluated along a line, it is called a velocity profile (as in, e.g., law of the wall). Definition The flow velocity ''u'' of a fluid is a vector field : \mathbf=\mathbf(\mathbf,t), which gives the velocity of an '' element of fluid'' at a position \mathbf\, and time t.\, The flow speed ''q'' is the length of the flow velocity vector :q = \, \mathbf \, and is a scalar field. Uses The flow velocity of a fluid effectively describes everything about the motion of a fluid. Many physical properties of a fluid can be expressed mathematically in terms of the flow velocity. Some common examples follow: Steady flow The flow of a fluid is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotor (turbine)
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator.Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator.Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davangere
Davanagere is a city in the centre of the southern Indian state of Karnataka. It is the seventh largest city in the state, and the administrative headquarters of eponymous Davangere district. Hitherto being a cotton hub and hence popularly known before as ''the Manchester of Karnataka'', the commercial ventures of the city is now dominated by education and agro-processing industries. Davanagere became a separate district in 1997, when it was separated from the erstwhile undivided district of Chitradurga for administration conveniences. Davanagere is known for rich culinary traditions which encompass the diversity of entire Karnataka's dishes due to its geographical position in the state as its centre. Notable among them is its aromatic benne dosey/butter Dosa that is associated with the name of the city. Davanagere was selected as one of the hundred Indian cities to be developed as a smart city under Central government's Smart Cities Mission. It was among the first 20 towns to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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