Isochor
Definition
... a process at constant volume, denoted by a vertical line on a pV diagram and a curve on a Ts diagram.
Where it occurs.
In the theoretical Otto Cycle, heat is added and rejected at constant volume. In the theoretical Diesel Cycle, heat is rejected at constant volume. Constant volume heating/ cooling might also apply to fluid storage tanks.
Special features
If a the volume of a system is fixed, then the system can do no work.
How to draw it
Locate the POI and press the isochor button.
The theory
At (T,s) for a given POI, thepressure follows from, rearrangement and integration of the Gibbs Equation.
$$ p = 1.013 \, exp( s/R) (T/273.)^{(\gamma/(\gamma-1)} $$
From the Ideal Gas Law, specific volume follows
$$ v = V/m = RT/p $$
The calculations of ideal gas internal energy and enthalpy are explained in conjunction with
the point of interest.
Exercises
Click on the graph to get a POI and plot an isochor through it. Click along the isochor to set new POIs and note how temperature increases with pressure.
Links
... to follow.