Pressure gradient calculation for air–water heterogeneous mixture flow in a small square horizontal channel based on the in situ parameters and flow pattern coefficient

The present understanding of even fully developed turbulent flow of a single-phase component in closed channels is not completely satisfactory. In the two-phase or multiphase flow of heterogeneous mixtures like gas–liquids many more independent parameters are involved, thereby making this process more complicated and less amenable to understanding, mathematical modeling and simulating or calculation of such parameter as the length pressure gradient. This paper presents an approach to incorporate flow pattern phenomena into a two-phase flow calculation model by (1) developing a mathematical model for pressure losses in two-phase flow based on in situ parameters, (2) developing and defining a flow pattern coefficient, which incorporates the flow pattern phenomena; and (3) present the developed mathematical model with the incorporation of flow patterns, which demonstrates a significant increase of accuracy of calculations for air–water two-phase mixture flow in a horizontal small square channel.