Phase-isolation is a novel ever-increasing multiphase separation technology, which can facilitate the multiphase fluid flowing concurrently with a substantially clear interface between two phases, and the phenomenon is promisingly employed for the separation and measurement of multiphase flows. Phase-isolation can be implemented by different kinds of lateral forces, of which the centrifugal force induced by the swirlers is the most convenient method. The radial pressure drop between pipe wall and pipe center, and the axial pressure drop along the pipe wall occurs at the downstream of the swirler. In the paper, the coupling model of dual differential pressure (DDP) including the radial-axial differential pressure and radial-radial differential pressure was built employing centrifugal phase-isolation for oil-water two-phase flow, and the theoretical measurement models were validated by our experimental data. At certain cross sections downstream of the swirler, the deviations between theoretical and experimental result of the volumetric oil fraction λ_o and mass flowrate Q_m were below ±7.16% and ±1.14% respectively when the radial-axial differential pressure was adopted, while the deviations between theoretical and experimental result of λ_o and Q_m were below ±6.91% and ±1.13% respectively using the radial-radial differential pressure. The acceptable deviation indicates that the DDP model can be the reference for the analysis and application of two-phase flow in the academic research and practical engineering.

相隔离是一种新型的不断增加的多相分离技术，它可以促进多相流体同时流动，两相之间的界面基本清晰，这种现象有望用于多相流的分离和测量。相隔离可以通过不同类型的侧向力来实现，其中旋流器引起的离心力是最方便的方法。管壁与管心之间的径向压降和沿管壁的轴向压降发生在旋流器的下游。本文采用离心相隔离法建立了油水两相流的径向-轴向压差和径向-径向压差的双压差(DDP)耦合模型，并且我们的实验数据验证了理论测量模型。在旋流器下游的某些横截面，体积油分的理论和实验结果之间的偏差采用径向-轴向压差时，λ _o和质量流量Q _m分别低于±7.16%和±1.14%，而λ _o和Q _{m 的}理论与实验结果偏差低于±6.91%和±1.13%分别使用径向-径向压差。可接受的偏差表明DDP模型可以作为学术研究和实际工程中两相流分析和应用的参考。