Thermodynamic Properties of Liquid Vapour Mixtures

Saturated liquid: Liquid just on the point of vapourising

Saturated vapour: Vapour just on the point of condensing (dry vapour)

Compressed liquid: Liquid at a temperature lower than saturation temperature

Superheated vapour: Vapour not on the point of condensing, and with a temperature higher than saturation temperature

Wet vapour: Mixture of saturated liquid and vapour

Quality / Dryness fraction: \( x = \frac{m_{vapour}}{m_{tot}} \)


For mixtures, ideal gas law does not apply. For isentropic processes, \( PV^\gamma = Const. \) does not apply. Gas constants as well as specific heat constants do not apply.


For properties of a liquid vapour mixture:

\( y_{AV} = y_f + x( y_g - y_f) \)

Where \( y \) is any consistent property. ( \(v, h, s ... \) )