Pressure drop in a pipe
Pressure drop in a pipe
(OP)
hi,
I am trying to evaluate pressure drop in an oil pipe. My problem is that I know that there is also air involved (~ 0.1%). The question is, how does the air influence the pressure drop? (notice i am talking about 0.1% air)
I heard opinions both ways (pressure drop shall fall/rise) but no solid explanation.
please enlighten me...
thanx
guy
I am trying to evaluate pressure drop in an oil pipe. My problem is that I know that there is also air involved (~ 0.1%). The question is, how does the air influence the pressure drop? (notice i am talking about 0.1% air)
I heard opinions both ways (pressure drop shall fall/rise) but no solid explanation.
please enlighten me...
thanx
guy





RE: Pressure drop in a pipe
RE: Pressure drop in a pipe
This would imply (although not ensure) that 0.1% v/v air at room conditions would stay dissolved in the oil and not appreciably affect the friction drop as long as pressure doesn't drop too much and the gas is released from solution.
Sometimes air is chemically absorbed by the oil (oxidation) further reducing its availability. The solubility doesn't change much until profound chemical changes warrant a new Ostwald number.
The -as published- effect of temperature, T (absolute) on the Ostwald coefficient Co (at 273 K), is as follows: