What Mach Number Means

Quand cela s’applique

Use this guide when teams argue about whether incompressible assumptions are still valid at your velocities.

Browser-based preliminary check for Mach Number Calculator — fast estimates, not code or stamped design output.

1Compute local speed of sound from temperature and gas properties for your fluid.
2Divide flow speed by sound speed to get Mach number.
3Classify subsonic, transonic, and supersonic regimes for method selection.
4Revisit ideal gas assumptions when pressures or temperatures swing widely.
5Escalate to full compressible CFD when shocks and separation dominate.

Using sea-level sound speed at hot exhaust conditions.
Confusing mass-averaged vs area-averaged velocities in ducts.
Applying incompressible Bernoulli where Mach exceeds roughly 0.3 without checks.

Humidity changes properties slightly; document whether you use dry-air approximations.

Liquids have a sound speed too, but applications differ; context matters.

Use this guide when teams argue about whether incompressible assumptions are still valid at your velocities.

Browser-based preliminary check for Mach Number Calculator — fast estimates, not code or stamped design output.

1Compute local speed of sound from temperature and gas properties for your fluid.
2Divide flow speed by sound speed to get Mach number.
3Classify subsonic, transonic, and supersonic regimes for method selection.
4Revisit ideal gas assumptions when pressures or temperatures swing widely.
5Escalate to full compressible CFD when shocks and separation dominate.

Using sea-level sound speed at hot exhaust conditions.
Confusing mass-averaged vs area-averaged velocities in ducts.
Applying incompressible Bernoulli where Mach exceeds roughly 0.3 without checks.

Humidity changes properties slightly; document whether you use dry-air approximations.

Liquids have a sound speed too, but applications differ; context matters.