Abstract:
Sound speeds in air are computed with the traditional method and compare with those obtained with a simplified method. Data for both methods are derived from the constituents of standard air. With the traditional method, the virial coefficients of the constituents of air and their temperature derivatives are utilized. For the simplified method, only the real-gas specific heats of the constituents at constant pressure are used. It can be shown that with the simplified method, the computed sound speeds for nitrogen which is the major constituent in air, are in better agreement with published nitrogen sound-speed experimental data. Uncertainties of both methods are discussed.