Turbulent Flow in Rod Bundles with Geometrical Disturbances

The results of measurements of shear stress distribution around wetted surfaces and velocity fields of turbulent flow in rod bundles with geometrical disturbances are presented. Experiments were performed on an aerodynamic model composed of 19 rods in a hexagonal arrangement 6 m long with an outside diameter of 120 mm and a pitch-to-diameter ratio of 1.17. The geometric disturbances were modeled by the displacement of the central rod from its regular position. An important influence of secondary flows on the velocity fields was revealed. From the experimental data, empirical formulas for shear stress distribution were derived.