ABSTRACT
One-dimensional (1D) modelling is important for turbocharger unsteady performance prediction and system response assessment of internal combustion engine. Two limbs of twin-entry turbines deliver pulsating unsteady flows with 180° phase difference leading to significant mixing at the rotor inlet. Such effects cannot be reproduced in classic 1D modelling and hence the predictions by the latter are less satisfactory in twin-entry turbines. To solve this problem, the paper proposes a novel 1D modelling (TURBODYNA) and applies it to a twin-entry turbocharger turbine. Instead of applying constant pressure assumption at the limbs junction, TURBODYNA solves conservation equations during the mixing process. Unsteady source terms described by dynamic equations are added into Euler equation to simulation rotor unsteady performance. By comparing TURBODYNA with validated CFD, TURBODYNA not only provides a great agreement on turbine performances, but also accurately captures unsteady features with increased pulsating frequency.
