View source for Isochore (volume)

[[Category:Done 2021-10-29]] 
[[File:Isochore.png|thumb|500px|right|Figure 1. The [[PV diagram]] of an isochoric process]]
An '''isochore''' in the context of [[thermodynamics]] refers to any process in which the [[system]] remains at a constant (unchanging) volume. An isochoric process is modeled on a [[pressure volume diagram]] (PV diagram) as seen in Figure 1. For this process to be possible, the [[ideal gas law|ideal gas]] must be in a rigid container that doesn't change in volume or let any [[molecule]]s escape. 


During an isochoric process, if [[heat]] is added to the system it will be absorbed as internal energy. The ideal gas law <math>pV=nRT</math> states that increasing the internal energy (also known as [[temperature]]) will increase the pressure. If heat is removed from the system, the internal energy will decrease, and thus the pressure will decrease. 


Since the [[volume]] of the system is not changing, no pressure-volume [[work]] is done by or on the system.<ref>R. Knight, Physics for scientists and engineers. Boston, Mass.: Addison-Wesley, 2012, p. 474</ref>  This can be seen visually on the [[pressure]]-[[volume]] diagram (figure 1), as there is no area under the curve (since work is found by calculating the area under the curve). 


<math>W = 0</math> when the volume of the system is constant. 


One mechanism that uses the isochoric process is in [[heat engine]]s that use diesel and gasoline. The waste [[heat]] is expelled right after the vehicle or machine receives power from [[combustion]], but since the piston is not moving, the volume of the chamber is unchanging and the pressure drops. The process a gasoline engine undergoes is modeled by the [[Otto cycle]] (Figure 2) and diesel engines are modeled by the [[Diesel cycle]] (figure 3). 

An isochoric process is seen in steps 2 to 3 and steps 4 to 1 in a [[Otto cycle]], and in steps 4 to 1 in the [[Diesel cycle]]. 



<gallery caption= "Applications of the Isochore" mode=packed heights=260px>
File:P-V_Otto_cycle.png|Figure 2. The PV diagram of the Otto Cycle<ref>Wikimedia Commons [Online], Available: https://en.wikipedia.org/wiki/Otto_cycle#/media/File:P-V_Otto_cycle.svg</ref>
File:diesel cycle.jpg|Figure 3. The PV diagram of the Diesel Cycle<ref>"File:Grafico p-v.JPG - Wikimedia Commons", Commons.wikimedia.org, 2018. [Online]. Available: https://commons.wikimedia.org/wiki/File:Grafico_p-v.JPG. [Accessed: 10- Jul- 2018].</ref>
</gallery>

==For Further Reading==
*[[Pressure volume diagram]]
*[[Heat]]
*[[Temperature]]
*[[Ideal gas law]]
*[[Isobar]]
*[[Isothermal]]
*[[Adiabatic]]
*Or explore a [[Special:Random| random page]]

==References==
{{reflist}}