tnhrbtnhb - 9-4-2007 at 08:50
Does anyone know how, if at all, the viscosity of a gas changes with pressure?
I want to calculate the volume of water vapor that will flow through a 1 1/8 inch (2.86 cm) pipe at 15 torr difference between ends and 30 torr
absolute pressure at the input.
Water is boiling in one vessel at low pressure and flowing through the tube to condense in the other.
[Edited on 9-4-2007 by tnhrbtnhb]
Magpie - 9-4-2007 at 13:13
I can't offhand tell you the effect of pressure on the viscosity of steam, but:
From "Flow of Fluids through Valves, Fittings & Pipe" - Crane Technical Paper 410, I find that the viscosity of saturated steam at 1 psia is 0.010
centipoise (cP), at 2 psia = 0.010 cP, at 5 psia = 0.011 cP. So at 30 torr (0.59 psia) and 45 torr I would think it would also be darn close to 0.010
cP.
tnhrbtnhb - 10-4-2007 at 16:02
Thanks.
Yeah, I figured it would be close, just from looking at the viscosity of other gasses at various pressures.... just wanted to make sure before I build
:-).