CFD modeling of pressure drop, pressure drop fluctuations and flow regimes in horizontal pneumatic conveying at low velocities using a two-fluid model

For optimizing pneumatic conveying systems, it is essential to determine the velocity range at which the minimum pressure drop occurs. Computational fluid dynamics (CFD), particularly using the Eulerian two-fluid model, provides effective means of simulating the pneumatic conveying of fine granular materials, regardless of particle count. In this study, OpenFOAM's transient twoPhaseEulerFoam solver is used to simulate horizontal pneumatic conveying at a range of velocities, including low speeds. Material related parameters were calibrated to match the pressure drop values obtained from experimental data in literature. Initially, the specularity coefficient was calibrated while maintaining a constant particle-particle restitution coefficient, and this calibration was applied to explore various particle-particle restitution coefficients. Pressure drop, pressure fluctuations, and flow regimes were then analyzed across different gas velocities and solid mass flow rates. The simulations predict pressure drop and flow regimes with good accuracy. Although simulated pressure drop fluctuations qualitatively match experimental results, they differ quantitatively. • Dense flow pneumatic conveying is modeled by the two-fluid model (TFM). • Calibration of particle-particle restitution and specularity coefficient. • Pressure drop well predicted for different flow regimes. • Pressure drop fluctuations show qualitatively reasonable results. • Flow regimes are predicted mostly correctly, with certain deviations.