Phase-Average Mean Flow and Turbulence Structure in a Staggered Cylinder Array Subjected to Pulsating Cross-Flow

Abstract

The unsteady turbulent flow field in a staggered array of cylinders with streamwise and transverse spacing to diameter ratios of 2.1 and 3.6, respectively, was studied experimentally by means of laser-Doppler anemometry for a Reynolds number of 2300. Flow pulsations in the streamwise direction were employed to control the frequency of vortex shedding in the array as has been previously demonstrated in Konstantinidis et al. [1]. Under these conditions, it was possible to obtain velocity measurements and for each velocity sample assign the phase-angle with respect to the pulsation cycle. This methodology allowed reconstruction of the unsteady (periodic) mean flow and random turbulence fields over an average vortex shedding cycle. The experimental data obtained are analyzed and the results offer a unique insight into the flow processes that take place inside the cylinder array.