An improved void fraction prediction model for gas-liquid two-phase flows in pipeline-riser systems

•The phase interface in the upstream horizontal section was reconstructed using ECVT.•Upstream interface drop and slugging are induced by the flow in the riser.•Lockhart-Martinelli model is found to be best and is used for improved correlation.•An improved void fraction prediction model is proposed for pipeline-riser systems.•This improved model leads to considerably reduced prediction errors.