SONIC VELOCITY

SONIC VELOCITY (Speed of Sound in a Gas)

This calculator determines the sonic velocity of a gas, which represents the speed at which pressure waves travel through the fluid. Sonic velocity is a key reference in gas flow analysis, especially when checking whether flow conditions may approach choking or other compressibility-related behavior.

Inputs Used
  • Sonic Velocity (Vs) (ft/s) – Calculated output value
  • Absolute Temperature (T) (°R) – Gas temperature in absolute units
  • Ratio of Specific Heats (k) (typically 1.4) – Cp/Cv ratio for the gas
  • Acceleration by Gravity (g) (ft/s2) – Used for unit consistency
  • Universal Gas Constant (R) (1544 / mol·wt) – Gas constant in English units
How Sonic Velocity Is Calculated

Sonic velocity is computed using the standard thermodynamic relationship:

Vs = √(k · g · R · T)

Where Vs is in ft/s and T must be in °R.

Interpretation
  • Higher temperature (T) increases sonic velocity.
  • Higher k increases sonic velocity (pressure waves travel faster).
  • Sonic velocity is often used as a reference to assess whether gas flow velocity is approaching sonic / choked conditions.

Use this tool to quickly estimate gas sonic velocity and understand velocity limits under your operating conditions.

Speed of Sound in a Gas
Pressure wave propagation through sparse particles
T
°R
K
g
ft/(s^2)
R
/mol wt

Sonic Velocity (Vs): {{Sonic_velocity:Decimal;#,##0.00}} Ft/s

Disclaimer: The information provided by this calculator is intended for informational and educations purposes only. The default figures shown are hypothetical and may not be applicable to your individual situation. We are not responsible for the consequences of any decisions or actions taken in reliance upon or as a result of the information provided by this tool. We are not responsible for any human errors or omissions.