The air flow around and above the metallic wire on the carding cylinder without any covering plate was simulated by water flow with the same Reynold's number in the tow-dimensional open channel around and above a transparent plastic model wire of twenty times large. Polystylene beads of 0.5_??_1.0mm dia, or aluminum flakes suspended in the water visualized the velocity distribution at various sections with the aid of photometry with a slit and a chopper. The techniques were almost the same as reported previously.
1)It was found that the flow became turbulent and the velocity distributions were formed as shown in Fig. 3 above the tip of the saw-toothed model wire or above the top hedge of the flat model wire, and that the flow was considered to be laminar and the velocity distributions were formed as shown in Fig. 6 and Fig. 7 under the tip or the top hedge of both model wires.
Friction coefficients calculated from these velocity distributions were 0.02 for the saw-toothed model wire and 0.009 for the flat model wire respectively. The difference in these values showed that the saw-toothed part of wire was efficiently resistant to the uniform flow.
Close agreement between our experimental results and other's about the velocity distribution was confirmatively shown in Fig. 10.
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