Quantifying Local Wall Shear Stresses in the Rotated Cage

Abstract In a cooperative project between industry and research institutes, local wall shear stresses at corrosion coupons tested in rotated cages were quantified for the first time via electrochemical measurements at microelectrodes flush-mounted in dummy coupons at characteristic surface sites (leading edge, trailing edge, outside surface). The tracer system was the hexacyanoferrate(II/III) redox couple. Besides geometric parameters the influence of medium parameters (density, viscosity) was investigated. It is now possible to link cage test data to actual service flow conditions and make application-specific use of the advantages of rotated cage experiments.