Fluid flow in pipes of rectangular cross sections

Head loss due to fluid friction was measured in smooth conduits of rectangular cross section. The data covers the laminar and turbulent range. Results were compared with previous theoretical and empirical data. The customary practice of calculating head loss in non-circular conduits by use of the friction factor obtained on an “equivalent” circular pipe was discussed. It was found that this practice is successful in square cross sections undergoing turbulent flow. In laminar flow, however, this method is not accurate --Abstract, page ii