Sensitivity and optimization CFD analysis of a vane-type pipe separator based on the AIAD model

• VTPS Efficiency: The vane-type pipe separator (VTPS) is effective for compact, high-efficiency oil-water separation in constrained oilfield environments. • Advanced Modeling: A computational framework using the AIAD model within an Euler-Euler multiphase context is developed and experimentally validated. • Key Parameters Identified: Sensitivity analysis reveals guide vane angle and oil fraction as dominant factors affecting pressure drop and oil recovery. • Optimization Approach: Multi-objective optimization using SPEA2 and TOPSIS identifies the best trade-off between oil recovery and hydraulic loss. • Optimal Design Achieved: An optimal VTPS setup (25.4° vane angle, 3.57 m³/h flow rate, 18.4% oil fraction, 0.12 split ratio) achieves a 0.162 oil recovery factor at 2422 Pa pressure drop. Efficient oil-water separation is increasingly vital in mature oilfields, where enhanced water production challenges conventional downhole separation technologies. The vane-type pipe separator (VTPS) offers a promising solution due to its compact configuration and superior phase separation efficiency in constrained environments. However, the inherent complexities of swirling multiphase flow necessitate advanced modeling approaches for performance optimization. In this study, a comprehensive computational framework based on the Algebraic Interfacial Area Density (AIAD) model within an Euler-Euler multiphase context is developed and validated against benchmarked experimental data. Sensitivity analysis employing response surface methodology (RSM) and global-local indices quantifies the influence of key decision parameters, including guide vane installation angle, inlet flow rate, oil fraction, and split ratio, on separator performance. The study elucidates the parametric interplay affecting pressure drop and oil recovery, revealing guide vane angle and oil fraction as the dominant factors for hydraulic and separation performance, respectively. A multi-objective optimization is conducted using the Strength Pareto Evolutionary Algorithm 2 (SPEA2), with final selection by TOPSIS, to maximize oil recovery while minimizing hydraulic losses. The proposed methodology identifies an optimal configuration with a 25.4° vane angle, 3.57 m³/h flow rate, 18.4% oil fraction, and 0.12 split ratio, achieving a 0.162 oil recovery factor at a pressure drop of 2422 Pa. These findings provide actionable guidelines for VTPS design and operation, facilitating more efficient separation in oilfield applications and demonstrating the AIAD model's efficacy for industrial-scale multiphase flow optimization.