11th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
In the last decades, turbocharger technology has enabled the improvement of automotive internal combustion engines through downsizing, which promotes an interest in enlarging surge limit to increase engine low end torque. However, the operation in these conditions can be noisy. The objective of the work is the aeroacustical and flow analysis of a vaneless diffuser compressor by means of transient CFD calculations validated with experiments. Detached-eddy simulations from best efficiency to near surge conditions are performed. In the experimental apparatus, the compressor is installed in an anechoic chamber where dynamic pressure sensors located in the pipes allow the estimation of incoming and outgoing pressure waves. The results show that CFD calculations predict some features of experimental pressure spectra, whereas others are not properly captured. The model is also used to describe time-averaged flow field at different operating conditions. Also, a periodic oscillation of the detached boundary layer at blades suction side for best efficiency working point is found.