What Mach Number Means
适用场景
Use this guide when teams argue about whether incompressible assumptions are still valid at your velocities.
要使用的工具
Browser-based preliminary check for Mach Number Calculator — fast estimates, not code or stamped design output.
打开 Mach Number Calculator →步骤
- 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.
示例
- HVAC duct velocities vs compressibility (often negligible).
- Nozzle screening in propulsion coursework.
应避免
- 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.
相关工具
博客
工程 中的更多内容
常见问题
Humid air?
Humidity changes properties slightly; document whether you use dry-air approximations.
Liquid Mach?
Liquids have a sound speed too, but applications differ; context matters.