Mechanisms underlying transitional and turbulent boundary layer (TBL) flow-induced noise in underwater acoustics (II)

Abstract
This research applies dynamical system methods (i.e., Chaos Theory) to the processing of time sequences of transitional and turbulent wall-pressures impinging on the face of station probes mounted along the wall of an axisymmetric body of revolution during a buoyant ascent from the bottom of a deep water test basin. It is demonstrated that the turbulent pressure fluctuations for this experiment can be described as a dynamical system of sufficiently low order (i.e., less than ten degrees of freedom). This opens up several possibilities for the control of turbulence. In underwater acoustics this translates to flow noise reduction in sonar applications and to drag reduction in ship dynamics. Other potential commercial applications include control of flow through pipelines, and aerodynamic design.