Rayleigh Flow Calculator
Frictionless duct flow with heat addition. Type into any white box and both flows that this much heat can choke appear together, at any γ.
| Quantity | Subsonic heated up to sonic | Supersonic heated down to sonic |
|---|
Heat added, against Mach number
T₀/T₀*
supersonic floor
M = 1, choked
What this is computing
NOT WRITTEN YET — Iliya writes this, 300–500 words.
Deliberately loud so it cannot ship by accident. Worth covering:
- That heating drives both branches towards M = 1, and cooling drives them away — the same shape as Fanno, from a completely different mechanism.
- The static temperature peak. T/T* is largest at M = 1/√γ, below sonic, so between that point and choking you are adding heat and the gas is getting colder. Worth saying why: the kinetic energy is rising faster than the heat goes in.
- That this is why T/T* is shown here but cannot be typed in — it is not monotonic, so a value of it does not identify a state. Everything else on the page does.
- Thermal choking, and what happens if you add more heat than T₀/T₀* = 1 allows: the flow does not cross sonic, the inlet conditions change instead.
- Why the supersonic branch has a floor on how little heat it can carry, and what that means for a combustor running supersonically.