[an error occurred while processing this directive] next up previous contents
Next: Empirical Correlations Up: POST-CHF HEAT TRANSFER Previous: Introduction and Objectives

8.2. Post-CHF Heat Transfer Models and Correlations

Three types of modelling approaches have been attempted:

  1. Correlations of an empirical nature which made no assumption whatever about the mechanism involved in post-CHF heat transfer, but solely attempts a functional relationship between the heat transfer coefficient and the independent variables. This assumes that the vapor and liquid are at the saturation temperature and in thermodynamic equilibrium.
  2. Correlations which recognize that departure from thermodynamic equilibrium condition can occur and attempt to calculate the "true" vapor quality and vapor temperature, different from tex2html_wrap_inline4283 . A conventional single-phase heat transfer correlation for the vapor is then used to calculate the heated wall temperature.
  3. Semi-theoretical models where attempts have been made to examine and derive equations for the various individual hydrodynamic and heat transfer processes occurring in the heated channel and relate these to the wall temperature (or heat flux depending on the boundary conditions).

Groeneveld (1973) has compiled a bank of carefully selected data drawn from a variety of experimental post-dryout studies in tubular, annular and rod bundle geometries for steam/water flows.

All contents © Michael L. Corradini
Last Modified: Tue Sep 2 15:06:55 CDT 1997