Isentropic Flow Calculator
Calculate compressible flow properties for supersonic and subsonic flows through nozzles and diffusers
Isentropic Flow Calculation
Ratio of flow velocity to speed of sound
Air: 1.4, Helium: 1.67, CO₂: 1.28
Example Calculation
Supersonic Nozzle Flow
Given:
• Mach number: M = 2.0
• Stagnation pressure: P₀ = 0.69 bar
• Stagnation temperature: T₀ = 310 K
• Throat area: A* = 0.1 m²
Results
Static pressure: 0.128 bar
Static temperature: 172.2 K
Area ratio A/A*: 1.687
Mach angle: 30.0°
Flow Regimes
Subsonic Flow
Velocity less than speed of sound
Converging nozzle accelerates flow
Sonic Flow
Velocity equals speed of sound
Occurs at nozzle throat
Supersonic Flow
Velocity greater than speed of sound
Diverging nozzle accelerates flow
Key Formulas
Mach Number
M = c/a
Flow velocity / speed of sound
Pressure Ratio
p/p₀ = (1 + (γ-1)/2·M²)^(-γ/(γ-1))
Static to stagnation pressure
Temperature Ratio
T/T₀ = 1/(1 + (γ-1)/2·M²)
Static to stagnation temperature
Mach Angle
μ = sin⁻¹(1/M)
For supersonic flow (M > 1)
Understanding Isentropic Flow
What is Isentropic Flow?
Isentropic flow is a thermodynamic process where entropy remains constant throughout the flow. This occurs when there is no heat addition or removal, and viscous effects are negligible. It's fundamental to understanding gas dynamics in nozzles, diffusers, and jet engines.
Applications
- •Jet engine nozzles and intakes
- •Rocket propulsion systems
- •Wind tunnel design
- •Gas turbine engines
Flow Conditions
Stagnation: Conditions at zero velocity
Static: Local flow conditions
Critical: Conditions at sonic point (M = 1)
Key Assumptions
- •No heat transfer (adiabatic)
- •No friction (inviscid)
- •Steady flow conditions
- •Perfect gas behavior