The pressure–velocity correlation in oscillatory turbulent flow between a pair of bluff bodies

Turbulent flow measurements were conducted between two bluff bodies set in uniform flow in tandem arrangement. The velocity field obtained with PIV was averaged with respect to either time or phase of periodic pressure oscillation induced by vortex shedding from the bluff body, i.e., Reynolds decomposition or three-level decomposition. The Reynolds stresses caused by periodic fluid motion was found excessively large compared with those related to turbulent fluctuations in the entire flow field in observation. The PIV data were used to solve the discrete Poisson equation of instantaneous pressure. The effect of organized vortex motion caused strong correlations between velocity and pressure gradient when observed from the framework of the Reynolds averaging.