Turbulent Wall-Pressure Fluctuations in the CICLoPE Facility

Wall-pressure spectra and coherence between wall-pressure and streamwise velocity in a turbulent pipe flow are presented. An experimental investigation was conducted in the CICLoPE long-pipe facility at friction Reynolds numbers in the range of 4700 less than or similar to Re-tau less than or similar to 46 000. Wall-pressure energy spectra reveal an alignment of the inner-spectral peak location in terms of lambda(+)(x) approximate to 250, as well as an increase in overall energy content with increasing Re-tau. Linear coherence spectra between wall-pressure and streamwise velocity in the logarithmic region follow a Reynolds-number-independent wall-scaling. Identification of such a universal scaling contributes to compelling evidence that wall-pressure sensing, as an input for real-time flow control, is a feasible approach for implementation in practical engineering systems.