Physics
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Isentropic Flow Calculator.
Calculate ideal-gas stagnation temperature and pressure from static conditions, Mach number, and heat-capacity ratio.
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Educational model with every parameter shown. No material, weather, equipment, or safety defaults are inferred.
Use Cases
Aerodynamic design and analysis
Engineers use stagnation properties to evaluate flow conditions at stagnation points, such as on aircraft leading edges or in engine inlets, where the flow is brought to rest.
Example: For air at static temperature 300 K, pressure 101325 Pa, Mach 2, γ=1.4, find stagnation temperature and pressure.
Compressible flow education
Students and educators can quickly compute stagnation properties to understand the effects of Mach number and gas properties on flow behavior.
Example: Compare stagnation pressure for Mach 0.5 vs Mach 3 at same static conditions.
Frequently Asked Questions
- What does the isentropic flow calculator compute?
- It computes the stagnation temperature and stagnation pressure of an ideal gas given the static temperature, static pressure, Mach number, and heat-capacity ratio (γ). These are the conditions if the flow is brought to rest isentropically.
- What are the inputs and units?
- You need to enter static temperature in Kelvin (K), static pressure in Pascals (Pa), Mach number (dimensionless), and heat-capacity ratio γ (dimensionless). The calculator then outputs stagnation temperature and pressure in the same units.
- Why is the heat-capacity ratio important?
- The heat-capacity ratio (γ = Cp/Cv) affects the relationship between static and stagnation properties. For air, γ is typically 1.4. Different gases have different γ values, which changes the calculated stagnation conditions.
Tips & Common Mistakes
Tips
- Ensure static temperature is in Kelvin, not Celsius, for correct calculations.
- Use consistent units: static pressure in Pascals (Pa) to get stagnation pressure in Pa.
- For air, use γ = 1.4; for other gases, check the specific heat ratio.
- Mach number is dimensionless; enter it as a positive number (typically ≥0).
Common Mistakes to Avoid
- Entering temperature in Celsius instead of Kelvin, leading to incorrect stagnation temperature.
- Using pressure in bar or atm without converting to Pascals, causing unit mismatch.
- Assuming γ = 1.4 for all gases, which is only valid for diatomic gases like air at moderate temperatures.
Last updated: August 13, 2026