A widely used dimensionless plot representing two-phase flow in pipes (see Fig. 6). Published by O. Baker in 1954 using experimental data for water, various flow (p. 26) regimes can be distinguished such as annular, bubbly, froth, plug, slug, stratified, and wavy flow. Corrections are made for two-phase flow mixtures with other densities and viscosities. Improved plots have subsequently been developed by other researchers.

Fig. 6