Eric S. Winkel

Bubble friction drag reduction in a high-Reynolds-number flat-plate turbulent boundary layer

Turbulent boundary layer skin friction in liquid flows may be reduced when bubbles are present near the surface on which the boundary layer forms. Prior experimental studies of this phenomenon reached downstream-distance-based Reynolds numbers (

Bubble-induced skin-friction drag reduction and the abrupt transition to air-layer drag reduction

Re_{x}

Using cross correlations of turbulent flow-induced ambient vibrations to estimate the structural impulse response. Application to structural health monitoring

) of several million, but potential applications may occur at

High-Reynolds-number turbulent boundary layer friction drag reduction from wall-injected polymer solutions

Re_{x}

The mean velocity profile of a smooth-flat-plate turbulent boundary layer at high Reynolds number

orders of magnitude higher. This paper presents results for

High-Reynolds-number turbulent-boundary-layer wall-pressure fluctuations with dilute polymer solutions

Re_{x}

High-Reynolds-Number Turbulent-Boundary-Layer Surface Pressure Fluctuations with Bubble or Polymer Additives

as high as 210 million from skin-friction drag-reduction experiments conducted in the USA Navys William B. Morgan Large Cavitation Channel (LCC). Here, a near-zero-pressure-gradient flat-plate turbulent boundary layer was generated on a 12.9 m long hydraulically smooth flat plate that spanned the 3 m wide test section. The test surface faced downward and air was injected at volumetric rates as high as 0.38 m

Turbulent boundary layer pressure fluctuations at large scales

^{3}

Structural monitoring from noise cross correlation

s

Bubble-size distributions produced by wall injection of air into flowing freshwater, saltwater and surfactant solutions

^{-1}