This report deals with two types of experiment to investigate the effect of geometry on friction factor. One was performed by varying the rod distance ratio, P/D from 1.036 to 1.565. The other was performed by varying the peripheral rod circle radius, B. In this study, 7 rods were installed hexagonally in a circular tube.
The results of measurements of friction factor over a range of Reynolds number $Re=2.0＼times;10^{4}-1.5＼times;10^{5}$ were compared with the prediction calculated by the method which allows the prediction of friction factor for turbulent flow in non-circular channel if only laminar geometry factor is known.
It turns out from this investigation that for the turbulent flow, the variation of friction factor according to the variation of geometry is stolider than that for the laminar flow. It was also shown that as the Reynolds number increases, the distribution of friction factor against the location of the peripheral rods has a tendency to be uniform. Resuls of the experiment is well consistent with the prediction when P/D is above 1.2.
