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dillonmhudson
Oct6-10, 02:33 PM
Can you or can you not use specific volume to find quality? I know it can be found using mass but can you use specific volume?

brewnog
Oct6-10, 03:37 PM
Quality of what?

dillonmhudson
Oct6-10, 03:40 PM
Um THE quality:
http://www.engineersedge.com/thermodynamics/quality.htm

When given a mixture of water vapor and liquid water.

dillonmhudson
Oct6-10, 05:02 PM
Vapor quality according to wiki:
http://en.wikipedia.org/wiki/Vapor_quality

Q_Goest
Oct6-10, 06:30 PM
Can you or can you not use specific volume to find quality? I know it can be found using mass but can you use specific volume?
You could if you also know something else about the fluid. For example, pressure or temperature. You could also find it if you knew enthalpy, entropy, internal energy or some other state variable (http://www.physicsforums.com/showthread.php?t=54198). What you're trying to do is determine the state of the fluid, which you can't do with just one state variable (http://www.splung.com/content/sid/6/page/statevariables), you need 2.

For example, let's say we have steam with a specific volume of 0.0435 ft3/lbm. If that steam is at atmospheric pressure (saturation temperature 212 F), the quality is roughly 0.1%. But if the pressure is 1000 psig (saturation temperature 547 F), the quality is roughly 44%. You need a second state variable to pin down the physical state of the fluid.