ON THE STEADY-STATE PERFORMANCE OF NATURAL CIRCULATION LOOPS

This paper reports a comparison between natural and forced circulation data in a figure-of-eight loop relevant to a pressure tube type heavy water reactor. It is shown that both friction and heat transfer are affected by the presence of buoyancy induced secondary flows under steady-state natural circulation conditions. Several past proposals for correlating the overall hydraulic loss coefficient are reviewed and a generalized correlation is proposed that is non-loop specific. The correlation successfully predicts experimental data from three different loops. The experimental data, however, are generated with seven different geometric configurations of these three loops.