Dynamical analysis of electrochemical wall shear rate measurements

The performance of a circular electrochemical wall shear rate probe under unsteady flow conditions is analysed through a combined ezxperimental, numerical and analytical approach. The experiments are performed with a ferri- and ferrocyanide redox couple and compared to finite element analysis of the two-dimensional time-dependent convection-diffusion equation. The results are related to the analytical Leveque solution for steady flow and for some cases to Pedley's model for heat transfer in reversing shear flow (Pedley 1976). The steady flow analyses showed that in our experiments axial diffusion is only of minor importance but that for the lower Peclet numbers