# Mollier Diagrams

## Mollier Diagrams

There are six interrelated properties that define the state of steam: Temperature Pressure Dryness Fraction (within the saturated zone) Enthalpy Internal energy Entropy Fixing the value of any two properties defines the value of all the others. Thus fixing the values of Enthalpy and Entropy is sufficient to define Temperature, Pressure and Internal Energy of […]

## Steam Tables

Steam Tables Steam tables used to be (and may still be) published in the form of a small booklet listing values of steam temperature, pressure, specific volume (i.e. the volume of 1kg of steam at a given temperature and pressure), specific entropy, specific enthalpy against various input values, separate sets of tables being provided for […]

## Thermodynamic Anomalies

Anomalies in Thermodynamics Draft Text Only – Readers’ suggestions and inputs are welcome Thermodynamics is not an easy subject to master and there are many instances where it defies intuitive judgement. The following examples are offered by way of enlightenment and perhaps education: Steam viscosity increases with temperature Whilst it is intuitive that liquids become […]

## Enthalpy

Enthalpy is a “term of convenience” that is useful in the interpretation and application of Thermodynamics. Enthalpy is basically a measure of energy, but its main function is in the calculation and measurement of “flow energy” or gaseous energy (e.g. steam energy). [Note (borrowed from mathpages.com): Enthalpy is not a specific form of energy. It […]

## Entropy

Entropy Draft Text Only – Readers’ suggestions and inputs are welcome When a car or locomotive runs or brakes, we say that the heat escaping from it is “lost”. The Second Law of Thermodynamics explains this by saying that “energy will tend to dissipate from a hot or high energy body to a cold or […]

## Thermodynamic Equations

Page Under Development This page is still “under development”. Please contact the webmaster@advanced-steam.org if you would like to help by contributing text to this or any other page. Thermodynamics Nomenclature: T = temperature (oK) V = volume of system (cubic metres) P or p = pressure at the boundary of the system and its environment, […]

## Thermodynamics

Draft Text Only – Readers’ suggestions and inputs are welcome Introduction Oliver Bullied, disciple of Gresley and famously progressive CME of the Southern Railway, is often quoted as saying “Thermodynamics never sold a single locomotive” (or words to that effect) when commenting on Chapelon’s contemporary locomotive developments in France. Whether true or apocryphal, the remark […]

## Thermodynamic Definitions

Page Under Development This page is still “under development”. Please contact the webmaster@advanced-steam.org if you would like to help by contributing text to this or any other page. Definitions of thermodynamic concepts such as Entropy and Enthalpy are provided on separate pages of this website. Numerous useful (and often diverse) definitions of these and other […]