Mixed Convection and High-Pressure Low-Flow Steam Cooling Data from a 64-Rod Bundle

摘要

Heat transfer data were obtained from low flow steam cooling experiments in a partially uncovered 64-rod bundle. These tests indicated that free convection effects were superimposed on the laminar and turbulent forced convection heat transfer. This paper describes the influence of buoyancy on laminar and turbulent forced convection heat transfer coefficients. Mechanisms due to buoyancy which alter the local heat transfer are summarized. Criteria indicating the importance of buoyancy on laminar and turbulent upflow in a vertical pipe were developed and compared to other criteria found in the literature. These criteria were used to determine the steam cooling data with significant buoyancy influence. Data with buoyancy influence were compared to mixed convection correlations and to a numerical study for rod bundles. (ERA citation 09:047837)