The Westinghouse-3 (W-3 or W3) correlation for evaluation of critical heat flux (CHF)

One of the most widely used correlations for evaluation of critical heat flux (CHF) in PWR is the Westinghouse-3 (W-3) correlation. For predicting the CHF condition in a non-uniform heat flux channel, we use these two steps:

1. The uniform critical heat flux is computed with the W-3 correlation
2. The non-uniform critical heat flux distribution is then obtained by dividing the uniform critical heat flux  by the F factor.

For uniformly heated channels, the critical heat flux is given by:

Where:

The axially non-uniform heat flux is obtained by applying a corrective F factor to the uniform critical heat flux:

Where:

Source: N.E. Todreas and Mujid S. Kazimi, Nuclear Systems I – Thermal Hydraulic Fundamentals, Hemisphere Publishing Corporation, New York (1990), page 558.

Useful links:

• Material from MIT
• Material from NCSU