Measurement of fluid flow resistance for forced cooled underground transmission lines

Isothermal tests of a pipe type cable system were made in both the laminar and turbulent flow regimes. Transition to turbulent flow occurs at much lower Reynolds number than for bare pipes. The flow resistence is strongly influenced by skid wire geometry in the turbulent region and by cable configuration in the laminar region. Previous theoretical predictions for flow resistence in the laminar region are in error by twenty percent.