Criteria for the Onset of Mixed Convection and Onset of Recirculation in Vertical Rod Bundles

摘要

Criteria were developed for the onset of recirculation and onset of mixed convection in vertical rod bundles. It was concluded that the dominant mechanisms governing mixed convection in rod bundles are the frictional and buoyancy forces. By balancing these two terms, the key dimensionless parameters were identified as Re and B*. The criteria was expressed in terms of a flow regime map of Re versus B*. It was found that the onset of mixed convection could be predicted with forced convection input parameters, but for the onset of recirculation the effect of buoyancy on mixing was important. (ERA citation 09:007532)