Fatigue Analysis and Solid Particle Erosion Behavior of Nozzle Ring for Marine Turbocharger

This study investigates the degradation characteristics of turbocharger nozzle rings in marine diesel engines by conducting numerical analysis and solid particle erosion (SPE) tests to examine their structural stability and morphological surface damage trends. The fatigue analysis was conducted under a load condition corresponding to 100% output of the main engine, using ANSYS software. The SPE test was conducted in accordance with ASTM G76-05 standards, and the weight loss and erosion rate were calculated. Surface damage was closely examined through 3D analysis and scanning electron microscopy (SEM). The flow analysis revealed that the loads were highly concentrated at the nozzle ring inlet and the leading edge of the blades, with a maximum pressure coefficient of 0.07678 MPa. The load decreased toward the trailing edge of the nozzle ring, and the surface pressure coefficients of the flange, inner hoop, and outer hoop—where the nozzle ring blades are fixed—were found to be nearly identical. The fatigue life of the nozzle ring under 100% engine load was calculated as 1.377e⁺⁷ cycles, with a fatigue damage value of 1.32e⁺³². Notably, the fatigue life in the regions near the inner and outer hoops of the nozzle ring approached zero. The results of the SPE test using spherical SiO₂ particles confirmed that the surface damage of the nozzle ring material, 316L stainless steel, followed a typical ductile material damage mechanism. In addition, the surface damage characteristics were significantly influenced by SPE test parameters such as the shape of solid particles, nozzle diameter, and impact angle.