Speed of Sound in Water and Steam

Fig. 6. Speed of sound in water and steam as a function of temperature. Values given correspond to pressures in MPa. To convert MPa to psi, multiply by...

Transport Properties. Viscosity, themial conductivity, the speed of sound, and various combinations of these with other properties are called steam transport properties, which are important in engineering calculations. The speed of sound (Fig. 6) is important to choking phenomena, where the flow of steam is no longer simply related to the difference in pressure. Thermal conductivity (Fig. 7) is important to the design of heat-transfer apparatus (see HeaT-EXCHANGETECHNOLOGy). The viscosity, ie, the resistance to flow under pressure, is shown in Figure 8. The sharp declines evident in each of these properties occur at the transition from Hquid to gas phase, ie, from water to steam. The surface tension between water and steam is shown in Figure 9. 

These table snmmarize the thermophysical properties of water and steam at tem-peratnres up to 100°C (373.15 K) and pressure of 1 bar in liquid state. The tabulated properties are pressure (P), density (p), enthalpy (//), entropy (5), isochoric heat capacity (C,), isobaric heat capacity (Cp), speed of sound (m), viscosity (q), thermal conductivity (K), and static dielectric constant (D). 

The addition of carbon dioxide (up to 15% volume content) or water steam (up to 30% volume content) has little effect on the H2 + air mixture detonation velocity. The heat capacity ratio remains in the range of y = 1.36-1.4 and the sound speed -in the range of c = 320-350 m/s. 

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