There are about 500 empirical correlations out there (o yeah the world is HUGE man! :mrgreen:) to predict the critical heat flux (CHF), one of the most widely used correlations is (was?) the Westinghouse-3 (W-3) correlation. For predicting the CHF condition in a non-uniform heat flux channel, we follow these two steps:
- The uniform critical heat flux is computed with the W-3 correlation
- The non-uniform critical heat flux distribution is then obtained by employing the so-called “F factor“.
For uniformly heated channels, the critical heat flux is given by:
The axially non-uniform heat flux is obtained by applying a corrective F factor to the uniform critical heat flux:
The correlation is valid in the ranges:
Source: N.E. Todreas and Mujid S. Kazimi, Nuclear Systems I – Thermal Hydraulic Fundamentals, Hemisphere Publishing Corporation, New York (1990), page 558.
- Material from MIT [quickview]
- Material from NCSU [quickview]
- Material from Forschungszentrum Karlsruhe [quickview]
A variation of this W-3 correlation is the so-called W-3L correlation, which employs a correction factor to take into account the effect from grid spacer and/or mixing vane.