The state of a calorically-perfect gas is represented by a simple model. If the gas is accelerated to some speed without increasing its entropy, its thermodynamic energy is exchanged for kinetic energy. It is customary to characterize the state of such a moving gas in terms of its reservoir (aka stagnation, aka total) state.
This model converts between static and total states. It incorporates the usual isentropic relations; however, it makes no representations about the spatial scale of the flow or whether it is internal or external (so does not represent the spatial aspects of quasi-1D duct flows, for example the area ratio). Also this model solves some special situations where there is incomplete information about both states.
Press ⏎ to see the model. Try your own inputs or the examples below. Refresh your browser to clear results.
Mach number and static state
- Choose a Mach number of 0.5 M = 0.5 ⏎. The model infers temperature ratio, and other ratios if you assert that the state is not a vacuum (which can also be done by asserting pressure as below).
- Specify the static state with any two state variables, such as temperature T = 300 ⏎ and pressure P = 1E5 ⏎.
Key results are the total state Total ⏎ and the static state Static ⏎.