Transcription of FLOW OF GASES THROUGH TUBES AND ORIFICES
{{id}} {{{paragraph}}}
Example: bankruptcy
FLOW OF GASES THROUGH TUBES AND ORIFICES
2 FLOW OF GASES THROUGH TUBES AND ORIFICES R. Gordon Livesey The nature of gas flow in pipes and ducts changes with the gas pressure and its description is generally divided into three parts or regimes. The flow dynamics are characterized by A, the molecular mean free path, in relation to some characteristic dimension such as the diameter of a pipe. The flow regime cannot be determined from the mean free path alone but only from the relation of this parameter to the characteristic dimension. The relation is known as the Knudsen number, defined as* 1 Kn=d' Three regimes are generally identified: ( ) 1. Free Molecular Flow. The mean free path is of the same order as, or greater than, the characteristic dimension (the range of relatively large Knudsen numbers)~ and gas dynamics are dominated by molecular collisions with the walls of the retaining vessel or pipe.
Applications of vacuum technology range from the lowest pressures attainable « 10-14 mbar) through to around atmospheric pressure, ... engineers and rough calculations are often sufficient, so that approximations will be given wherever possible. Equations for the molecular, continuum and transitional
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: