Design Optimization of a Vortex Chamber for Erosion Mitigation in 90° Elbow Using the Taguchi Method

Severe localized erosion in 90-degree elbows is a critical issue in gas-solid two-phase flow pipeline systems. To mitigate this problem, this study proposes a novel elbow structure equipped with a vortex chamber. Computational Fluid Dynamics (CFD) coupled with the Taguchi orthogonal experimental design was utilized to optimize three core geometric parameters: vortex chamber radius (r), truncation angle (alpha) and horizontal offset distance (h). The Reynolds Stress Model (RSM) and Discrete Phase Model (DPM) combined with the Oka erosion model were employed to investigate the flow field, particle dynamics, and erosion characteristics. The results of detailed statistical analysis revealed that the vortex chamber radius has the most significant impact on erosion intensity. Through a multi-index comprehensive evaluation balancing erosion resistance and pressure drop, the optimal structural combination was determined as r of 60 mm, alpha of 0 degrees, and h of-6 mm. Compared with the standard elbow, this optimal configuration reduces the maximum erosion intensity by approximately 46.5% while maintaining pressure drop within an controllable range. The anti-erosion mechanism is primarily attributed to the chamber's ability to capture high-speed particles and generate a stable recirculating vortex, which dissipates particle kinetic energy and shifts the high-shear zone away from the outer wall.