Back pressure
From Wikipedia, the free encyclopedia
Backpressure usually refers to the pressure exerted on a moving fluid by obstructions or tight bends in the confinement vessel along which it is moving, such as piping or air vents, against its direction of flow. For example, an automotive exhaust muffler with a particularly high number of twists, bends, turns and right angles could be described as having particularly high backpressure [1]. Back Pressure in the exhaust sense of the term, is usually termed as being a "bad thing" for performance, however in the ever increasing vigilance of the law, back pressure can be regulated to keep exhaust noise down using systems from simple butterfly valves to fully computer controlled units sensing pressure in the exhaust pipe itself.
The term is also used analogously in the field of information technology to describe the build-up of data behind an I/O switch if the buffers are full and incapable of receiving any more data; the transmitting device halts the sending of data packets until the buffers have been emptied and are once more capable of storing information [2].
