A plenum chamber is a pressurised housing containing a fluid (typically air) at positive pressure . One of its functions is to equalise pressure for more even distribution, compensating for irregular supply or demand. It is typically relatively large in volume and thus has relatively low velocity compared to the system's other components. In wind tunnels, rockets, and many flow applications, it is a chamber upstream on the fluid flow where the fluid initially resides (approximately at rest). It can also work as an acoustic silencer.
14-677: [REDACTED] Look up plenum in Wiktionary, the free dictionary. Plenum may refer to: Plenum chamber , a chamber intended to contain air, gas, or liquid at positive pressure Plenism, or Horror vacui (physics) the concept that "nature abhors a vacuum" Plenum (meeting) , a meeting of a deliberative assembly in which all members are present; contrast with quorum Plenum space , enclosed spaces (in buildings) used for airflow Plenum cable , electrical wire permitted in plenum spaces per building codes Plenum Publishing Corporation ,
28-405: A light water reactor. Airbox An airbox is an empty chamber on the inlet of most combustion engines. It collects air from outside and feeds it to the intake hoses of each cylinder. Older engines drew air directly from the surroundings into each individual carburetor . Modern engines instead draw air into an airbox, which is connected by individual hoses to each carburetor or directly to
42-433: A pressure raised slightly above atmospheric pressure, in contrast to the "vacuum system" which used a pressure below atmospheric. At a time when high pressure steam or hydraulic systems were well established, these were a distinct set of systems based on low pressure and high volume flows. Supercharged piston engines typically use many cylinders arranged in-line and one or two superchargers. Superchargers deliver air at
56-450: A publisher of scientific books and journals Plenum (physics) , a space completely filled with matter Undergravel filters , in aquarium filtration, an open space under a layer of gravel or sand Air-mixing plenum , a place where ducts meet See also [ edit ] Plenary (disambiguation) , the related adjective Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
70-419: A relatively constant rate, while cylinders demand it in a varying manner, as the valves open and as piston speed varies through the stroke . Simple direct ducting would give problems where the nearest cylinders received more airflow. The pulsating demand from the cylinders would also show problems of either pressure waves in the duct, or a shortage of inlet air towards the end of the inlet phase. The solution
84-445: Is to provide a large-volume plenum chamber between the inlet and the cylinders. This has two benefits: it evens out the difference in path restriction between cylinders (distribution across space), secondly it provides a large-volume buffer against pressure changes (distribution over time). For non-supercharged / normally aspirated engines see Airbox . The Norton Classic was a motorcycle whose air-cooled twin-rotor Wankel engine
98-438: The bike's semi-monocoque frame) enabled the transfer of much of the heat to the surrounding atmosphere. The carburation process further reduced temperatures via the heat of evaporation. Even so, at 50 °C the fuel-air mixture was still hotter than ideal, and the engine's volumetric efficiency remained somewhat impaired. The eccentric shaft's main bearings and the inlet manifolds were fed by oil-injection lubrication, and
112-469: The fuel-air mix also carried residual mist of oil from the interior of the rotors, which helped to lubricate the rotor tips. Practical hovercraft use a peripheral skirt system, where the air from the lift fans is routed to a narrow slot around the edge of the hull, and bound by a flexible skirt. Distribution of this air from the fans to the periphery is through a large-volume plenum chamber, so as to provide even distribution of airflow without sensitivity to
126-426: The intake ports in fuel-injected engines, thus avoiding an extra intake manifold. The airbox allows the use of one air filter instead of multiples, reducing complexity. Developments arising from concerns about engine emissions during the late 1970s allow the airbox to collect pump gases from the crankcase and the tank air vent and re-feed them to the engine. Since the 1990s, engine designers also sought to exploit
140-432: The length of the direct path. Molten salts consisting of chlorinated nuclear waste are contained in atomic fission reactor rods. This Alvin M. Weinberg et al design has a liquid fuel instead of a solid fuel. The gas plenum is above the fuel and below a diving bell style vent for the reaction products. This allows for convection currents and fluid flow eliminating the possibility for gas products to build up and rupture as in
154-654: The properties of oscillating gas to improve performance. Many high-performance motorcycles have the airbox fed from funnels in the front of the bike, where increased pressure forces more air into the intake and thus improves power. Examples of this ram-air intake construction are the SRAD models of the Suzuki GSX-R750 , the Kawasaki Ninja ZX-6R or the BMW S1000RR . Secondly, designers exploit
SECTION 10
#1732765608167168-517: The title Plenum . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Plenum&oldid=905172101 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Plenum chamber Examples of plenum chambers include those used with: The term "plenum"
182-509: Was coined in the 1670s, derived from Latin adjective plenus ("filled, full"). The usage originates from classical theories of physics and the notion that " nature abhors a vacuum ". These gave rise to the notion of 17th century 'plenum' as the opposite of vacuum , and all things "being either Plenum or Vacuum". By the 19th century, the development of mechanical fans and industrial machinery had provided another, more technical use. This referred to "a system of artificial ventilation", which used
196-419: Was developed by David Garside at BSA . Wankel engines run very hot, so Garside gave this air-cooled motor additional interior air-cooling. Air was drawn through a forward-facing filter situated to provide a ram air effect. This air passed through the interior of the rotors and then into a large pressed-steel plenum before entering the combustion chambers via twin carburettors. The plenum (which doubled as
#166833