Isentropic Flow Calculator

Calculate thermodynamic properties across an isentropic flow. Isentropic flow is a flow process where entropy remains constant, which occurs in ideal compressible flow with no heat transfer or friction.

Isentropic Flow Results

Enter values and select calculation mode to compute isentropic flow properties.

Isentropic Flow Theory

What is Isentropic Flow?

Isentropic flow is a compressible fluid flow where entropy remains constant. This occurs when:

  • The flow is adiabatic (no heat transfer)
  • The flow is reversible (no viscous effects or friction)
  • No shock waves are present
  • The fluid can be modeled as a perfect gas

Key Properties and Terminology

  • Stagnation properties: Values when flow is brought to rest isentropically (denoted with subscript ₀)
  • Area ratio (A/A*): Ratio of local area to the critical area where M=1
  • Mach angle (μ): Angle of Mach waves in supersonic flow, calculated as sin⁻¹(1/M)
  • Prandtl-Meyer function (ν): Maximum angle through which supersonic flow can turn in expansion

Applications

Nozzle Design

Isentropic flow relations are used in designing rocket and jet engine nozzles to properly expand supersonic exhaust flow.

Wind Tunnel Testing

Used to calculate flow conditions in different parts of supersonic and hypersonic wind tunnels for aerodynamic testing.

Supersonic Inlets

For designing efficient inlets for supersonic aircraft that slow down air with minimum total pressure loss.