Local shear stress measurements with microelectrodes in turbulent flow of drag reducing surfactant solutions

The local wall shear stress, in turbulent flow of drag reducing and corrosion inhibiting surfactant solutions, was measured from polarographic mass transfer experiments using microelectrodes. A good agreement was observed between these values and those obtained by pressure drop measurements in a rectangular channel of high aspect ratio (10:1). Irreversible degradation was not observed in these systems at variance with polymer solutions