Reduced order model to predict volute tongue-induced unsteady loading on a radial turbine blade*

Turbochargers (T/Cs) are extensively utilized in the automotive industry due to their ability to augment the output of an internal combustion engine without necessitating an increase in cylinder capacity. In aviation, turbochargers adapted from ground-based applications are frequently employed in intermittent combustion engines to enhance efficiency and performance. However, these turbochargers often operate under off-design conditions and are susceptible to blade failures caused by aerodynamic-induced resonances. In this study, a one-dimensional (1D) methodology is employed to model the T/C turbine, integrating a T/C dynamic model with a flow model to simulate unsteady loading within the turbine. The model resolves the turbine volute flow using 1D viscous equations, taking into account the volute curvature and the circumferentially continuous flow exiting at the volute outlet. The turbine rotor is modeled using a meanline approach. This model is adept at predicting tongue-induced unsteady loading and provides the necessary parameters for subsequent three-dimensional simulations. The 1D results are currently compared with those obtained from three-dimensional unsteady simulations. This comparison aims to validate the 1D model's capability in accurately predicting unsteady loading on the T/C radial turbine blade.