Gas flow viscous

In experiments which are carried out under normal pressure, the gaseous products are taken from a modified, commercially available low temperature furnace. The gas flows viscously in the specially designed capillary through an intermediate volume to the peristaltic pump. Hereby the gas pressure in the intermediate volume is reduced to approx. 1 mm Hg. By means of a variable... 

Type of gas flow Viscous flow Knudsen flow Molecular flow Molecular flow... 

From values of / and c, the diffusion coefficient (D) and dynamic viscosity (q) can be calculated (Examples 1.16-1.19). Estimation of the Knudsen (H d) and Reynold s numbers defines the nature of gas flow (viscous, molecular, intermediate) in vacuum systems (Examples 1.20-1.22). 

Low-speed gas flows viscous dissipation and compressibility terms are negligible. Boundary-layer flows streamwise diffusion terms are negligible. 

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