Measurement of transition boiling boundaries in forced convective flow

An investigation was carried out to determine whether, during the quenching of a hot-surface e.g. during emergency core cooling of a nuclear reactor, 1) the minimum heat flux corresponds to the initiation of liquid contact on a surface and 2) whether the critical heat flux corresponds to the initiation of continuous liquid contact. The test section, probe, thermocouple, and probe circuit are described and results are given. The experiment showed that an electric resistance probe can be used to detect changes in cooling modes on a heated surface under forced convective conditions. (U.K.)