# Stefan Number

## Description

Sensible heat is heat exchanged by a body or thermodynamic system that changes the temperature, and some macroscopic variables of the body, but leaves unchanged certain other macroscopic variables, such as volume or pressure. Latent heat is the energy released or absorbed by a body or a thermodynamic system during a constant-temperature process. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. The Stefan number (St or Ste) is defined as the ratio of sensible heat to latent heat.

It is a dimensionless parameter that is useful in analyzing a Stefan problem. The parameter was developed from Josef Stefan’s calculations of the rate of phase change of water into ice on the polar ice caps.

## Variables

Ste | Stefan number (dimensionless) |

c_{p} | specific heat (J/K*kg) |

ΔT | temperature difference between phases (sensible heat) (K) |

L | latent heat of melting (J/kg) |