Flow measurement in an impinging jet cell with three-segment microelectrocles

Three-dimensional flow close to the stagnation point of an impinging jet cell was studied by means of three-segment electrodiffusion probes. The total current and the directional characteristics providing the wall velocity gradient and the flow direction respectively were measured at different distances from the stagnation point. The linear dependence of the wall velocity gradient on this distance was confirmed in the stagnation zone. The normal velocity component was evaluated from the flatness of the directional characteristics. The values of the normal velocity component were rather higher than those corresponding to the linear change of the velocity gradient and the dimensionless ratio of the probe radius to distance. The deviation appearing on the normal velocity component was explained by geometrical imperfections of the probes due to the technology of fabrication.This work was supported by the grant no. 101(9511421 awarded by the Grant Agency of the Czech Republic.