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Rayleigh Flow Calculator — Heat-Addition Compressible Ratios
Calculate Rayleigh-line static and stagnation property ratios relative to sonic conditions for a perfect gas.
Last updated: September 17, 2026
Results
Formula, example and assumptions
P/P*=(γ+1)/(1+γM²); T/T*=[(γ+1)M/(1+γM²)]²; T0/T0*=2(γ+1)M²[1+(γ−1)M²/2]/(1+γM²)².
For air at M=0.5, the ratios quantify the heat-addition margin before thermal choking at M=1.
- Steady frictionless one-dimensional constant-area ideal-gas flow.
- No mass addition or shaft work; heat transfer drives the state along the Rayleigh line.
Frequently asked questions
What does this Rayleigh Flow Calculator solve?
Calculate Rayleigh-line static and stagnation property ratios relative to sonic conditions for a perfect gas.
Which units should I use?
Use the units printed beside each input. Dimensionless ratios need no conversion; pressure inputs used in gas equations are absolute unless the field explicitly says differential.
Is this suitable for final engineering design?
Use it for transparent first-pass calculations and cross-checks. Final design should verify gas or fluid properties, geometry, loss data, equipment curves and the applicable engineering standard.