Numerical Simulation of Effective Medium Approximation Using Monte Carlo Method and Its Experimental Evaluation

The phase fraction in the industrial multi-phase flows is a key factor affecting the process efficiency and safety. The capacitance and other impedance based sensors can be employed to estimate this parameter by resorting to the effective medium approximation (EMA) method, which describes the macroscopic properties of composite materials with analytical or theoretical modeling. The EMAs have been paid increasingly attentions in determining the phase fraction in the multi-phase flow. There exist several different EMA models that can be utilized for phase fraction measurement, i.e., Maxwell-Garnett, Bruggeman and Böttcher models. It is essential to evaluate feasibility of these EMA models in gas-solid two-phase flows with different flow regimes, i.e., the homogenous and laminar flows. A four-electrode capacitance sensor is evaluated to validate multiple EMA models for estimating the solid fraction by numerical simulations and static experiments. The numerical simulation work focuses on comparing the solid fraction results obtained from different EMA models by Monte Carlo method.