HEAT TRANSFER BETWEEN SUBCHANNELS IN A ROD BUNDLE
In designing fuel elements for nuclear reactors it is important to know the intersubchannel mixing. The mixing reduces the temperature differences in the fluid and makes it possible to increase the power for a given maximum surface temperature.
Several methods for prediction of mixing have been proposed but none of them seem to work for a general case.
This study was started with an experimental investigation, in which two configurations, pitch to diameter ratio 1.62 respectively 1.1, were tested.
On the basis of these experiments and other available data, it was possible to develop a calculation method which could predict mixing with reasonable accuracy for various channel geometries.