# Ammonia - Prandtl Number

## Figures and table showing changes in Prandtl number for ammonia with changes in temperature and pressure

**The Prandtl Number** - Pr - is a *dimensionless number* approximating the ratio of *momentum diffusivity* (kinematic viscosity) to *thermal diffusivity* - and is often used in heat transfer and free and forced convection calculations.

The Prandtl number can for calculations be expressed as

Pr = μ C

_{p}/ k (1)where

μ = absolute or dynamic viscosity (kg/m s, lb_{m}/(ft h))

C_{p}= specific heat (J/kg K, Btu/(lb_{m}^{o}F))

k = thermal conductivity (W/m K, Btu/(h ft^{2}^{o}F/ft))

Below, Prandtl numbers for **ammonia** at varying temperatures and pressures are given in figures and table.

See also** ammonia: **Thermophysical properties, Properties at gas-liquid equilibrium conditions and Density and specific weight, Specific heat, Viscosity, and Thermal conductivity at varying temperature and pressure, as well as **Prandtl number** of air, carbon dioxide, methane and water.** **

Ammonia Prandtl number at gas-liquid equilibrium pressure, temperature given as °C or °F:

Ammonia Prandtl number at atmospheric pressure, temperature given as °C:

Ammonia Prandtl number at varying temperatures at given constant pressures, SI and Imperial units:

Back to top

Ammonia Prandtl number at given temperatures and 1, 10, 50 and 100 bara presure:

Temperature | Prandtl number at given pressures | |||||

[K] | [°C] | [°F] | 1 bara | 10 bara | 50 bara | 100 bara |

200 | -73.2 | -8.6 | 2.67 | 2.67 | 2.69 | 2.72 |

239.56 | -33.6 | 13.3 | 1.71(liq) | |||

239.56 | -33.6 | 13.3 | 0.881(g) | |||

298.05 | 24.9 | 45.8 | 1.30 (liq) | |||

298.05 | 24.9 | 45.8 | 1.18 (g) | |||

300 | 26.9 | 46.9 | 0.876 | 1.16 | 1.29 | 1.29 |

362.03 | 88.9 | 81.4 | 1.41 (liq) | |||

362.03 | 88.9 | 81.4 | 1.84 (g) | |||

398.32 | 125 | 102 | 3.59 (liq) | |||

398.32 | 125 | 102 | 4.85 (g) | |||

400 | 127 | 102 | 0.857 | 0.894 | 1.11 | 3.24 |

500 | 227 | 158 | 0.835 | 0.846 | 0.903 | 0.998 |

600 | 327 | 214 | 0.855 | 0.860 | 0.883 | 0.913 |

700 | 427 | 269 | 0.952 | 0.955 | 0.965 | 0.976 |

## Related Topics

## Related Documents

## Tag Search

- en: ammonia prandtl number viscosity heat capacity thermal conductivity