| How do I choose between polytropic efficiency and isentropic efficiency? |
| Other inputs included the degree of superheat and subcooling, isentropic efficiency of the compressor etc. |
| The isentropic surface varies in height from place to place over the Earth, the variation being indicated on the isentropic chart by isobars, lines showing the pressure at which the isentropic surface is found. |
| In the same way the critical point of the isentropic curves comes nearer to that of the isothermals. |
| The first and third legs are nearly isothermal, while the second and fourth legs are nearly isentropic. |
| Because air particles tend to flow along isentropic surfaces rather than at constant levels, the life history of air currents can be conveniently followed from day to day by means of isentropic charts. |
