Design optimization of guide vane for mitigating elbow erosion using computational fluid dynamics and response surface methodology

•A 90̊ elbow equipped with guide vane was developed to reduce elbow erosion.•Response R1 shows a quadratic perturbation with the change of structure factors.•Response R2 has a linear relationship with the selected structure factors.•The optimal geometry was obtained by using a desirability function approach.•The modified elbow has a larger low-speed region and a lower DPM concentration.