Limits for the pressure volume curve
Definition
These set the maximum values on the y-axis (pressure) and x-axis (volume). The mass of gas in the system is defined.
Where it occurs
During compression pressures can rise dramatically, typically from 1 to 20 bar in an Otto cycle. So make sure that your pressure and volume limits are appropriate.
Special features
None
How to define it
You can overwrite the default values of 3 litres (max volume), 5 bar (max pressure), and 0.0036kg (mass) that present in text boxes on a newly opened page. Maximum volume and pressure will become evident on the graph next time you click on it. It is best to set pressure, volume and mass before any work is done.
The theory
According to the state postulate the thermodynamic state of a simple system can be specified by any two independent properties plus mass. Specifying pressure, volume and mass allows us to compute all other thermodynamic properties.
Exercises
Set the maximum volume to 6 litres, the maximum pressure to 10 bar and the mass to 0.0072 kg. Click on the graph and check that the scales change. The correct mass should be shown in the table. Locate the POI at the four corners of the graph and sanity check the pressures/ volumes shown in the table.
Links
... to be added.