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Discharge Coefficient
In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the ideal discharge,Sam Mannan, Frank P. Lee, ''Lee's Loss Prevention in the Process Industries: Hazard Identification, Assessment and Control'', Volume 1, Elsevier Butterworth Heinemann, 2005. (Google books)/ref> i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical working fluid from the same initial conditions to the same exit pressures. Mathematically the discharge coefficient may be related to the mass flow rate of a fluid through a straight tube of constant cross-sectional area through the following: : C_\text = \frac = \frac = \frac = \frac : C_\text = \frac Where: :C_\text, discharge coefficient through the constriction (dimensionless). :\dot, mass flow rate of fluid through constriction (mass per time). :\rho, density of fluid (mass per vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe (material), pipe. A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas). Nozzles are frequently used to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that emerges from them. In a nozzle, the velocity of fluid increases at the expense of its pressure energy. Types Jet A gas jet, fluid jet, or hydro jet is a nozzle intended to eject gas or fluid in a coherent stream into a surrounding medium. Gas jets are commonly found in gas stoves, ovens, or barbecues. Gas jets were commonly used for Gas lighting, light before the development of electric light. Other types of fluid jets are found in carburetors, where smooth calibrated orifices are used to regulate the flow of gasoline, fuel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Flow Rate
In physics and engineering, mass flow rate is the Temporal rate, rate at which mass of a substance changes over time. Its unit of measurement, unit is kilogram per second (kg/s) in SI units, and Slug (unit), slug per second or pound (mass), pound per second in US customary units. The common symbol is \dot (pronounced "m-dot"), although sometimes \mu (Greek language, Greek lowercase Mu (letter), mu) is used. Sometimes, mass flow rate as defined here is termed "mass flux" or "mass current". Confusingly, "mass flow" is also a term for mass flux, the rate of mass flow per unit of area. Formulation Mass flow rate is defined by the limit of a function, limit \dot = \lim_ \frac = \frac, i.e., the flow of mass \Delta m through a surface per time \Delta t. The overdot on \dot is Newton's notation for a time derivative. Since mass is a scalar (physics), scalar quantity, the mass flow rate (the time derivative of mass) is also a scalar quantity. The change in mass is the amount that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Working Fluid
For fluid power, a working fluid is a gas or liquid that primarily transfers force, motion, or mechanical energy. In hydraulics, water or hydraulic fluid transfers force between hydraulic components such as hydraulic pumps, hydraulic cylinders, and hydraulic motors that are assembled into hydraulic machinery, hydraulic drive systems, etc. In pneumatics, the working fluid is air or another gas which transfers force between pneumatic components such as compressors, vacuum pumps, pneumatic cylinders, and pneumatic motors. In pneumatic systems, the working gas also energy storage, stores energy because it is compressible. (Gases also heat up as they are compressed and cool as they expand. Some gases also condense into liquids as they are compressed and boil as pressure is reduced.) For passive heat transfer, a working fluid is a gas or liquid, usually called a coolant or heat transfer fluid, that primarily transfers heat into or out of a region of interest by conduction (heat), conduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Pressure
In fluid dynamics, dynamic pressure (denoted by or and sometimes called velocity pressure) is the quantity defined by:Clancy, L.J., ''Aerodynamics'', Section 3.5 :q = \frac\rho\, u^2 where (in SI units): * is the dynamic pressure in pascals (i.e., N/ m2), * (Greek letter rho) is the fluid mass density (e.g. in kg/m3), and * is the flow speed in m/s. It can be thought of as the fluid's kinetic energy per unit volume. For incompressible flow, the dynamic pressure of a fluid is the difference between its total pressure and static pressure. From Bernoulli's law, dynamic pressure is given by : p_0 - p_\text = \frac\rho\, u^2 where and are the total and static pressures, respectively. Physical meaning Dynamic pressure is the kinetic energy per unit volume of a fluid. Dynamic pressure is one of the terms of Bernoulli's equation, which can be derived from the conservation of energy for a fluid in motion. At a stagnation point the dynamic pressure is equal to the difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Coefficient
The flow coefficient of a device is a relative measure of its efficiency at allowing fluid flow. It describes the relationship between the pressure drop across an orifice valve or other assembly and the corresponding flow rate. A greater restriction in flow will create a larger pressure drop across a device and thus a smaller flow coefficient, conversely device with little restriction in flow will have a small pressure drop and a larger flow coefficient. For example, the flow coefficient of a 1" ball valve may be 80 while a similarly sized globe valve in the same application may be 10. Mathematically the flow coefficient (or flow-capacity rating of valve) can be expressed as C_\text = Q \sqrt, where, : is the rate of flow (expressed in US gallons per minute), : SG is the specific gravity of the fluid (for water = 1), : is the pressure drop across the valve (expressed in psi). In more practical terms, the ''flow coefficient'' is the volume (in US gallons) of water at that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orifice Plate
An orifice plate is a device used for measuring flow rate, reducing pressure or restricting flow (in the latter two cases it is often called a '). Description An orifice plate is a thin plate with a hole in it, which is usually placed in a pipe. When a fluid (whether liquid or gaseous) passes through the orifice, its pressure builds up slightly upstream of the orifice but as the fluid is forced to converge to pass through the hole, the velocity increases and the fluid pressure decreases. A little downstream of the orifice the flow reaches its point of maximum convergence, the ''vena contracta'' (see drawing to the right) where the velocity reaches its maximum and the pressure reaches its minimum. Beyond that, the flow expands, the velocity falls and the pressure increases. By measuring the difference in fluid pressure across tappings upstream and downstream of the plate, the flow rate can be obtained from Bernoulli's equation using coefficients established from extensive research. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
