Numerical and experimental study of oil droplet separation in a horizontal cascade impactor with a custom computational framework

This study introduces a novel Fluent & MATLAB-based computational framework for simulating oil droplet separation in a cascade impactor, validated through experimental testing. The impactor geometry was designed based on Marple’s theory, and flow dynamics were simulated to optimize efficiency. Due to the lack of specialized software for predicting liquid droplet separation, a custom numerical model was developed, enabling precise analysis of particle behavior under various aerodynamic forces. The proposed horizontal cascade impactor differs from conventional vertical designs by incorporating a pre-nozzle upstream of the main nozzle, strategically positioning the aggregation zone to minimize re-entrainment effects and improve measurement accuracy. Using a superposition method, the impact of each separation stage was quantified, and the optimal Stokes number was determined to maximize efficiency. Experimental validation was conducted by measuring the separated oil mass and comparing the results with numerical predictions. The findings demonstrate a high correlation between the computational and experimental results, with deviations analyzed in detail. This research provides a valuable tool for improving the design of separation systems, particularly in internal combustion engine emission control and aerosol studies.