Turbulent boundary layers on axially inclined cylinders. Part 1. Surface-pressure/velocity correlations

Abstract

The boundary layer on a cylinder with its axis at small inclinations of 0–6° to the freestream (an idealisation of `streamers' used in underwater seismic surveys) has been studied experimentally by measurements involving surface pressure fluctuations and their correlation with the axial velocity. There is no evidence of vortex shedding at Reynolds numbers typical of streamers at operating conditions. The behaviour of the wall-pressure field is substantially altered by small incidence: correlation length scales decrease on the upstream side, but remain relatively unaltered on the downstream side. Attention is also paid to the axisymmetry of the flow by reference to axial velocity statistics of up to fourth order.