Developed single-phase turbulent flow through a square-pitch rod cluster for an extended range of reynolds numbers.

Abstract

The mean velocity profiles wall shear stress distribution and all components of the Reynolds stress tensor have been determined from measurements for developed single-phase flow through a square-pitch rod cluster. For a rod pitch-to-diameter ratio of 1.107 four Reynolds numbers in the range 22.6 x 103 to 207.6 x 103 were investigated. The experimental technique which involved a rotatable inclined hot-wire anemometer probe allowed the measurement of secondary flow components of the order of 1 per cent of the local velocity. No evidence was found for secondary flows in the open rod gap area. The highly anisotropic nature of the turbulence particularly for the interconnecting rod gap region was shown by the level of the azimuthal turbulent shear stress. The mean velocity profiles were generally consistent with the logarithmic region of the universal velocity profile using the Patel values for the profile constants. The wall shear stress distribution measured by Preston tubes was shown to be symmetrical around the central rods of the array.