2 replies to this topic

[ayan_dg]

Common literature states that for flow through pipe lines, if Reynold's number is less than 2100 then the flow is laminar. If it is greater than 2300 the flow is turbulent & between 2100 & 2300 it is on transition zone. I want to know whether the above statement is valid for both liquid & gaseous flow as well.

[latexman]

My literature references are somewhat different from those you stated. For flow through pipe lines, if Reynold's number is less than 2100, the flow is laminar. If it is greater than 4000, the flow is turbulent. Between 2100 & 4000, it is in transition zone. This is valid for both liquid & gaseous flow. The dimensionless Reynold's number may be considered to be the ratio of the dynamic forces of mass flow to the shear stress due to viscosity. If these forces were considered separately without taking a ratio, they would be quite different for gases versus liquids. However since these forces are in a ratio in the Reynold's number, the same limits apply to gases and liquids. It normalizes the differences in physical properties.

[ayan_dg]

Thanks a lot "latexman"