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Orifice
{{Disambiguation ...
An orifice is any opening, mouth, hole or vent, as in a pipe, a plate, or a body * Body orifice, any opening in the body of a human or animal *Orifice plate, a restriction used to measure flow or to control pressure or flow, sometimes given specialised names: ** Calibrated orifice, used to control pressure or flow ** Restrictive flow orifice, used to control flow ** Miss Shilling's orifice, used to control flow in the engines of early Spitfire and Hurricane fighter aeroplanes * Back Orifice, a controversial computer program designed for remote system administration See also * Choked flow * Needle valve * Nozzle * Venturi effect * Flow measurement Flow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. The common types of flowmeters with industrial applications are listed below: * a) Obstruction type (differential pressure or variable area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back Orifice
Back Orifice (often shortened to BO) is a computer program designed for remote system administration. It enables a user to control a computer running the Microsoft Windows operating system from a remote location.Richtel, Matt.Hacker Group Says Program Can Exploit Microsoft Security Hole" ''The New York Times'' August 4, 1998. Retrieved April 24, 2007. The name is a play on words on Microsoft BackOffice Server software. It can also control multiple computers at the same time using imaging. Back Orifice has a client–server architecture. A small and unobtrusive server program is on one machine, which is remotely manipulated by a client program with a graphical user interface on another computer system. The two components communicate with one another using the TCP and/or UDP network protocols. In reference to the Leet phenomenon, this program commonly runs on port 31337. The program debuted at DEF CON 6 on August 1, 1998 and was the brainchild of Sir Dystic, a member of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orifice Plate
An orifice plate is a device used for measuring flow rate, for reducing pressure or for 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 r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calibrated Orifice
An orifice plate is a device used for measuring flow rate, for reducing pressure or for 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 r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restrictive Flow Orifice
A Restrictive Flow Orifice (RFO) is a type of orifice plate. They are used to limit the potential danger, damage, or wastage of an uncontrolled flow from, for example, a compressed gas cylinder They are generally not limiting the flow during normal operation but if a fault or failure occurs causing uncontrolled flow the orifice will present a restriction, limiting the flow. It may be used to limit the accidental release of a hazardous gas (flammable, toxic, etc.) resulting from regulator or other component failure, restricting flow in a system in order to assure adequate pressure relief valve sizing and system over pressure protection, or restricting flow from bulk sources such as a water main.Gas Flow Characterization of Restrictive Flow Orifice Devices, Sandia REPORT SAND97-1670, Jul. 1997 Predicting Flow Correlations assist in predicting the flow of a particular gas or gas mixture through a RFO. This is done by first determining the flow through the same RFO at the required pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choked Flow
Choked flow is a compressible flow effect. The parameter that becomes "choked" or "limited" is the fluid velocity. Choked flow is a fluid dynamic condition associated with the venturi effect. When a flowing fluid at a given pressure and temperature passes through a constriction (such as the throat of a convergent-divergent nozzle or a valve in a pipe) into a lower pressure environment the fluid velocity increases. At initially subsonic upstream conditions, the conservation of energy principle requires the fluid velocity to increase as it flows through the smaller cross-sectional area of the constriction. At the same time, the venturi effect causes the static pressure, and therefore the density, to decrease at the constriction. Choked flow is a limiting condition where the mass flow will not increase with a further decrease in the downstream pressure environment for a fixed upstream pressure and temperature. For homogeneous fluids, the physical point at which the choking occurs f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venturi Effect
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista Venturi. Background In inviscid fluid dynamics, an incompressible fluid's velocity must ''increase'' as it passes through a constriction in accord with the principle of mass continuity, while its static pressure must ''decrease'' in accord with the principle of conservation of mechanical energy (Bernoulli's principle). Thus, any gain in kinetic energy a fluid may attain by its increased velocity through a constriction is balanced by a drop in pressure. By measuring pressure, the flow rate can be determined, as in various flow measurement devices such as Venturi meters, Venturi nozzles and orifice plates. Referring to the adjacent diagram, using Bernoulli's equation in the special case of steady, incompressible, inviscid flows (such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Orifice
A body orifice is any opening in the body of an animal. External In a typical mammalian body such as the human body, the external body orifices are: * The nostrils, for breathing and the associated sense of smell * The mouth, for eating, breathing, and vocalizations such as speech * The ear canals, for the sense of hearing * The nasolacrimal ducts, to carry tears from the lacrimal sac into the nasal cavity * The anus, for defecation * In males, the urinary meatus, for urination and ejaculation * In females, the urinary meatus, for urination * In females, the vagina, for menstruation, sexual intercourse and childbirth * The nipple orifices Other animals may have some other body orifices: * cloaca, in birds, reptiles, amphibians, and some other animals * siphon in mollusk, arthropods, and some other animals Internal Internal orifices include the orifices of the outflow tracts of the heart, between the heart valves. See also *Internal urethral orifice * Mucosa * Muco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on the outside by the lips and inside by the pharynx. In tetrapods, it contains the tongue and, except for some like birds, teeth. This cavity is also known as the buccal cavity, from the Latin ''bucca'' ("cheek"). Some animal phyla, including arthropods, molluscs and chordates, have a complete digestive system, with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes. Development In the first multicellular animals, there was probably no mouth or gut and food particles were engulfed by the cells on the exterior surface by a process known as endocytosis. The particles became enclosed in vacuoles into which enzymes were secr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miss Shilling's Orifice
Miss Shilling's orifice was a very simple technical device made to counter engine cut-out in early Spitfire and Hurricane fighter aeroplanes during the Battle of Britain. While it was officially called the R.A.E. restrictor, it was referred to under various names, such as Miss Tilly's diaphragm or the Tilly orifice in reference to its inventor, Beatrice "Tilly" Shilling. Engine cut-out problems Early versions of the Rolls-Royce Merlin engine came equipped with an SU carburettor. When an aeroplane equipped with such an engine performed a negative G force manoeuvre (pitching the nose hard down), fuel was forced up to the top of the carburettor's float chamber rather than down into the engine, leading to loss of power. If the negative G continued, fuel collecting in the float chamber would force the float to the floor of the chamber. Since this float controlled the needle valve that regulated fuel intake, the carburettor would flood and drown the supercharger with an over-rich m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Needle Valve
A needle valve is a type of valve with a small port and a threaded, needle-shaped plunger. It allows precise regulation of flow, although it is generally only capable of relatively low flow rates. Construction and operation An instrument needle valve uses a tapered pin to gradually open a space for fine control of flow. The flow can be controlled and regulated with the use of a spindle. A needle valve has a relatively small orifice with a long, tapered seat, and a needle-shaped plunger on the end of a screw, which exactly fits the seat. As the screw is turned and the plunger retracted, flow between the seat and the plunger is possible; however, until the plunger is completely retracted, the fluid flow is significantly impeded. Since it takes many turns of the fine-threaded screw to retract the plunger, precise regulation of the flow rate is easily possible. The virtue of the needle valve is from the vernier effect of the ratio between the needle's length and its diameter ... [...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. 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 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 fuel into an engine, and in jacuzzis or spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
