Flow transitions in a partially filled rotating inclined pipe with continuous flow

Flow transitions in a partially-filled, rotating inclined smooth pipe with axial liquid (water) flow are studied in this work. Different flow patterns are identified experimentally and reported. The effects of liquid flow rate, pipe inclination, diameter and length on the flow transitions are also investigated. A flow regime map is developed based on Reynolds number and Froude number to understand the parametric dependence responsible for fluid flow transitions. This study is expected to provide a basis for predicting critical rotational speeds for flow transitions in a partially filled rotating smooth pipe.