Analysis of Inverse Method Applied on Sandwich Probes

Abstract

Parallel plate disks (PPD) are often used for analyzing the effect of small amplitude oscillations with different frequencies. These devices allow the imposing of a well-known flow kinematics. Mass transfer problems and, particularly, convection-diffusion problems relating wall shear rate to mass transfer can thus be studied. Mass transfer signals can be determined from a sandwich electrodiffusion (ED) sensor frequency response. The experimental database constructed was used to check the inverse method. Indeed, the inverse method (Rehimi et al., 2006, “Inverse Method for Electrochemical Diagnostics of Flows,” Int. J. Heat Mass Transfer, 49, pp. 1242–1254) applied on a sandwich ED sensor was analyzed by comparing its instantaneous numerical wall shear rates to the known local and instantaneous experimental wall shear rate. Oscillatory flows amplitudes, frequencies effects, and flow direction effect have been studied in order to test the robustness of the inverse method to such effects. The little difference between experimental and numerical results is probably caused by the sensitivity of the sandwich sensor to such flow directions or to the neglecting of the insulating gap effect on the inverse method.