Section summary |
---|

1. Definition of the
sound velocity |

2. How to calculate
the sound velocity |

3. References of
speed of sound in air |

4. Excel calculation tool for sound
velocity |

The sound velocity, sometimes also called the speed of sound, is
the distance traveled by a sound wave in a gas during a unit of
time. It is generally expressed in m/s and is used in many process
engineering calculations.

The following formula can be used to calculate the speed of sound in an ideal gas :

With :

a = speed of sound in m/s

k = specific
heat ratio or isentropic coefficient

R = perfect gas constant = 8314

T = gas temperature in K

M = molecular
weight in g/mol

Gas |
Speed of sound in m/s |

Air 20c | 343 m/s |

Air 100c | 386 m/s |

Air 150c | 410 m/s |

The following Excel calculation tool will allow you to calculate
the sound velocity for ideal gas : link
to Excel calculation tool