Eckert number

The Eckert number (Ec) is a dimensionless number used in continuum mechanics. It expresses the relationship between a flow's kinetic energy and the boundary layer enthalpy difference, and is used to characterize heat transfer dissipation.[1] It is named after Ernst R. G. Eckert.

It is defined as


  • u is the local flow velocity of the continuum,
  • cp is the constant-pressure local specific heat of the continuum,
  • is the difference between wall temperature and local temperature.