Dryness Fraction Definition
The dryness fraction, denoted by the symbol $x$, is a property used for saturated liquid-vapour mixtures. It represents the fraction of the total mass that is vapour.
Mathematically, it's defined as:
$x = \frac{m_{vapour}}{m_{total}} = \frac{m_{vapour}}{m_{liquid} + m_{vapour}}$
Interpreting Dryness Fraction Values
- A dryness fraction of $x = 0$ indicates that the substance is entirely in the saturated liquid state (100% liquid).
- A dryness fraction of $x = 1$ indicates that the substance is entirely in the saturated vapour state (100% vapour).
- Values between 0 and 1 ($0 < x < 1$) represent a mixture of saturated liquid and saturated vapour.
Dryness Fraction for Saturated Liquid
The question specifically asks for the dryness fraction of a saturated liquid. By definition, a saturated liquid contains no vapour. This means the mass of the vapour component is zero ($m_{vapour} = 0$).
Applying this to the formula:
$x = \frac{0}{m_{liquid} + 0} = 0$
Therefore, the dryness fraction of a saturated liquid is 0.
Important Questions from Thermodynamic Properties of Steam & Steam Tables
Vaporization refers to the change in state of matter from
- The properties of water are arranged in the steam tables as a functions of
Fill in the blank with the appropriate word(s) from the options.
In a steam table, the data always refers to the properties of steam at its _________.
The critical point of water is
The amount of water evaporated from and at 100 °C into dry saturated steam at atmospheric pressure is called
