[하이플럭스 기술자료] 백프레셔 (Back Pressure) 정의

[하이플럭스 기술자료]

배압, 백프레셔 (Back Pressure) 정의

Back Pressure는 유동유체의 흐름이 방해를 받아 유체의 흐름방향과 반대방향으로 유체에 가해지는 압려을 말하는 것으로서, piping 또는 aire vent 내부의 이물질, elbow나 bend 등의 복잡한 배관구조에 의해 유체의 자연스로운 흐름이 방해를 받는 경우, 유체가 제대로 흐르지 못하여 흐름의 반대방향으로 생기는 반발력에 의해 반대흐름이 발생할 수도 있따. 이런 경우에 대비하여 butterfly valve 또는 check valve와 같은 non-return valve를 설치하여 반대흐름을 차단하다.

 

Back pressure 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 back pressure. Back pressure, in the exhaust sense of the term, of a four-stroke engine is usually termed as being a "bad thing" for performance however, in the interest of reducing exhaust sound to levels allowable by public noise ordinances, back pressure can be regulated using systems from simple butterfly valves to fully computer controlled units sensing pressure in the exhaust pipi itself.
in a two-stroke engine however, a certain amount of exhaust backpressure is needed to prevent unburned fuel/air mixture passing right through the cylinders into the exhaust.