Description:
<jats:p>Flow pattern transition prediction models are presented for oil–water flow in horizontal pipes. The transition between stratified and nonstratified flow is predicted using Kelvin–Helmholtz (KH) stability analysis for long waves. New, simplified, and more practical physical mechanisms/mechanistic models are proposed for the prediction of the transition boundaries to semidispersed and to fully dispersed flow. The proposed flow pattern classification significantly simplifies the flow pattern map for liquid–liquid flow and agrees well with the experimental data.</jats:p>