Prediction of Erosion in Radial Turbine Components
Automotive radial turbines usually operate in extreme polluted environments, where the impingements of particles on blades cause erosion damage. This paper presents a numerical study of particle dynamics and erosion through the components of a radial inflow turbine based on a Lagrangian tracking in-house code. The particle trajectories, impacts and induced erosion were determined throughout the volute, vaneless nozzle and impeller. The number of particles, sizes and initial positions were known according to a specified concentration of sand particles AC-coarse (0–200 micron). The results of numerical simulations show that obtained trajectories are consistently different from those in axial flow turbines, owing to the nature of flow and direction of inward forces. Small size particles travel easily through the rotor passage, whereas large ones only cross a small part of the rotor then are centrifuged back to the volute till reducing in size by fragmentation. The maximum erosion wear is found on the rotor blade leading edge due to direct exposure to flux of particles at high velocities and incidences. Highly eroded area is observed on the blade suction side from the leading edge, due to particles consistently impacting this area. Several particles crossing through the rotor passage are found to impact the pressure surface only towards exducer. Small particles from pressure side crossing over the tip induce local erosion. The initial positions of blades are shown to have great effects on the rotor erosion patterns.