Assessment of the unsteady performance of a turbocharger radial turbine under pulsating flow conditions: Parametric study and modeling

A characteristic of radial turbines for turbocharger applications subject to pulsating flow is the deviation of the turbine performance compared with corresponding continuous flow conditions, typically associated with gas-stand experiments. The performance deviations under pulsating flow generate a hysteresis loop that encloses the performance line obtained in gas-stand conditions and their intensity is demonstrated to grow with increasing pulse amplitude and frequency. Predicting the performance deviations is of great interest to improve the predictive capabilities of reduced-order models and enhance engine-turbocharger matching.