Three dimensional unsteady analysis of a miniaturized pressure probe for turbocharger applications

Abstract Downsizing and turbocharging are nowadays widely spread techniques in automotive small-size internal combustion engines aimed at reducing the specific fuel consumption without affecting power output. Due to device small dimensions high temperature of exhaust-gases feeding turbine, a relevant amount heat is customarily exchanged between turbine compressor so that classical adiabatic approach could lead an inaccurate estimation performance. This paper preliminary investigates feasibility experimental procedure computing work as variation angular momentum via three-hole probe located impeller outlet. Because very reduced machine dimensions, torque measurements be difficult, intrusive nature measurement significantly affect accuracy collected data. For this reason, influence finite-size onto flow field numerically analysed solving Unsteady Reynolds-Averaged Navier Stokes equations with installed diffuser inlet. The closed k − ω SST turbulence model, while density-based commercial CFD package used integrate governing equation. Finally, pressure distribution azimuthal direction assess effects which, proposed case, result 0.47% (resp. 0.69%) difference when miniaturized diameter 1mm 1.5 mm) employed.