FLOW MEASUREMENT IN AN IMPINGING JET CELL WITH 3-SEGMENT MICROELECTRODES

Three-dimensional flow close to the stagnation point of an impinging j et cell was studied by means of three-segment electrodiffusion probes. The total current and the directional characteristics providing the w all velocity gradient and the flow direction respectively were measure d at different distances from the stagnation point. The linear depende nce of the wall velocity gradient on this distance was confirmed in th e stagnation zone. The normal velocity component was evaluated from th e flatness of the directional characteristics. The values of the norma l velocity component were rather higher than those corresponding to th e linear change of the velocity gradient and the dimensionless ratio o f the probe radius to distance. The deviation appearing on the normal velocity component was explained by geometrical imperfections of the p robes due to the technology of fabrication.