Search results
Results from the WOW.Com Content Network
In thermodynamics, the Joule–Thomson effect (also known as the Joule–Kelvin effect or Kelvin–Joule effect) describes the temperature change of a real gas or liquid (as differentiated from an ideal gas) when it is expanding; typically caused by the pressure loss from flow through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment.
This temperature change is known as the Joule–Thomson effect, and is exploited in the liquefaction of gases. Inversion temperature depends on the nature of the gas. For a van der Waals gas we can calculate the enthalpy using statistical mechanics as
The Joule–Thomson effect, the temperature change of a gas when it is forced through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment. The Gough–Joule effect or the Gow–Joule effect, which is the tendency of elastomers to contract if heated while they are under tension.
The Joule-Thomson (JT) cooler was invented by Carl von Linde and William Hampson so it is also called the Linde-Hampson cooler. It is a simple type of cooler which is widely applied as cryocooler or as the (final stage) of coolants. It can easily be miniaturized, but it is also used on a very large scale in the liquefaction of natural gas.
Thomson collaborated with Joule, mainly by correspondence, Joule conducting experiments, Thomson analysing the results and suggesting further experiments. The collaboration lasted from 1852 to 1856. Its published results did much to bring about general acceptance of Joule's work and the kinetic theory.
Quantity (common name/s) (Common) symbol/s Defining equation SI unit Dimension Temperature gradient: No standard symbol K⋅m −1: ΘL −1: Thermal conduction rate, thermal current, thermal/heat flux, thermal power transfer
This is the definition declared in the modern International System of Units in 1960. [13] The definition of the joule as J = kg⋅m 2 ⋅s −2 has remained unchanged since 1946, but the joule as a derived unit has inherited changes in the definitions of the second (in 1960 and 1967), the metre (in 1983) and the kilogram . [14]
The Thomson effect is an extension of the Peltier–Seebeck model and is credited to Lord Kelvin. Joule heating, the heat that is generated whenever a current is passed through a conductive material, is not generally termed a thermoelectric effect.