Design optimization of ribbed fluidic oscillator using integrated CFD-Taguchi-GRA method

Abstract

This study aims to optimize the flow performance of a double-feedback fluidic oscillator through an enhanced Coanda surface design. The focus is on improving oscillation frequency and jet deflection angle while reducing pressure drop, which are critical parameters in certain fluidic oscillator applications. An integrated approach using computational fluid dynamics modeling with the Taguchi-Grey relational analysis methodology is proposed. Three design factors; aspect ratio, number of ribs, and angle of ribs are analyzed, each for three levels: 0.64, 1.00, and 1.56; 4, 6, and 8; and 0°, −18.5°, and + 18.5° respectively. A two-dimensional CFD model is employed for simulations, and a Taguchi orthogonal array L9(3 ³) is used to investigate the influence of design variables on single and multiple responses. Weighted Grey Relational Analysis, supported by the Analytical Hierarchy Process, is utilized for multi-objective optimization, and analysis of variance to evaluate the significance of design factors. The results identified the number of ribs as the most dominant factor influencing the oscillation frequency and overall performance of the oscillator. The rib angle had a higher impact on the jet deflection angle, while the aspect ratio played a significant role in minimizing pressure drop. The optimized design achieved a 19.9 % increase in oscillation frequency, a 39.7 % enhancement in jet deflection angle, and a 17.6 % reduction in pressure drop. This study highlights key understandings of integrating CFD modeling with Taguchi-Grey relational analysis for multi-objective optimization of fluidic oscillators. Moreover, it also facilitates future advancements in fluidic oscillator performance.