Hydraulic nonuniformities and ''secondary flows'' in a model of tube-casing heat exchanger

The aerodynamic experiment is carried out on the model of an intermediate heat exchanger of a fast reactor NPP. The feature of such heat exchanger is lateral inflow and outflow of coolant of the intertube space. The tube bundle spread over the concentric circles. The testing has been carried out at Re being (16-32)x103, the inlet of air into the model has been performed from the damping chamber. A considerable hydraulic nonuniformity of the gas flow distribution over the apparatus cross section is observed. The following reasons of nonuniformities are shown: the difference in form factors in friction laws for various channels peripheral and central bundle channels, the display of ''secondary flow'' in the complex cross section box, loosely filled by the tube bundle