Introduction

This thesis offers new insights into the fluid flow behavior of automotive centrifugal compressors operating under near-stall conditions. Firstly it discusses the validation of three-dimensional computational fluid dynamics (CFD) unsteady simulations against acoustic experimental measurements using an original procedure based on plane wave pressure decomposition.

CFD Case Configuration

It then examines the configuration of the CFD cases, highlighting the key parameters needed for a successful calculation.

Flow Field Analysis

Moreover, it describes both the compressor mean and unsteady flow field from best-efficiency to near-surge operating points.

Phenomena at Reduced Flow Rates

Lastly, it provides readers with explanations of the various phenomena that arise when the mass flow rate is reduced and the compressor is driven to poor and noisy performance.

Target Audience and Practical Insights

Written for students, researchers and professionals who want to improve their understanding of the complex fluid flow behavior in centrifugal compressors, the thesis offers valuable practical insights into reducing the acoustic emissions of turbochargers.