Vortex flowmeters for simultaneous gas flow rate and particle loading measurement in dilute two-phase flows: CFD analysis of T-shaped bluff body

Real-time monitoring of particle loading in gas-solid two-phase flows is essential for process design, control, and optimization. This study introduces a new correlation to estimate both particle concentration and gas flow rate in dilute gas-particle flows using a vortex flow meter. It employs the Eulerian-Eulerian approach to investigate the particles’ effect on vortex shedding in a vortex flowmeter with a hybrid triangular T bluff body. The impacts of volume fraction, particle size, and Reynolds number on turbulence, pressure oscillation, and Strouhal number were analyzed. Particle loading decreased the shedding frequency by 28%–61% for 0.01% particle volume fraction. Unlike in single-phase flows, the Strouhal number varies with Reynolds number and declines in two-phase flow due to interphase momentum exchange and turbulence suppression. Analysis of parameters along the flowmeter’s centerline showed a reduction in lateral velocity and turbulence kinetic energy. A new empirical correlation was proposed to estimate the particle mass fraction (Yp) based on the normalized pressure drop relative to the single-phase baseline, incorporating a hydrodynamic correction factor to account for particle-fluid interactions. The study was conducted over a Reynolds number range of 39,334–191,000, and Stokes numbers from 0.4 to 1.8. The particle mass fraction (Yp) can be predicted with errors of less than 7%, over the particle volume fraction range of 0.01% to 0.075%, across the studied Reynolds number range. These findings support using a vortex flowmeter for simultaneous flow rate measurement and particle concentration monitoring in dilute two-phase flows.