Aspiration
The Roots blower is commonly used on the two stroke diesel engine, which requires some form of forced induction. In this application, the blower does not provide significant boost and these engines are considered naturally aspirated with the blower providing just slightly more than positive pressure as the device is acting as a positive displacement pump; turbochargers are generally used when significant boost is needed. In small engines, a conventional turbo will be followed by the blower. In large engines, particularly in railroad, marine or stationary services, the turbo is a combination turbo-compressor, with the compressor being driven by the crankshaft through an overrunning clutch during starting and at low rpms, and by the turbine with the clutch being disconnected when the exhaust gasses have reached sufficient temperature.
Read more about this topic: Two-stroke Diesel Engine
Famous quotes containing the word aspiration:
“I should think the American admiration of five-minute tourists has done more to kill the sacredness of old European beauty and aspiration than multitudes of bombs would have done.”
—D.H. (David Herbert)
“My aspiration now is to get by luck what I could not get by merit.”
—Mason Cooley (b. 1927)
“When delicate and feeling souls are separated, there is not a feature in the sky, not a movement of the elements, not an aspiration of the breeze, but hints some cause for a lover’s apprehension.”
—Richard Brinsley Sheridan (1751–1816)