Aerodynamic Investigation in Small Turbocharger Centrifugal compressor, Using Laser Doppler Anemometry and Particle Image Velocimetry

摘要

In the purpose of increasing the engine specific power at constant rotational speed (Downsizing), The most commonly used method is the use of a turbocharger. Due to spatial restrictions to which turbocharged engines are submitted in passenger cars, the compressor entry often requires a 90° bend with other complex geometries which generate a non-uniform flow resulting in a modification of the swirl at the compressor inlet. Consequently the performance map will be affected. Geometric changes effects on turbochargers are not very known. The presented work is a part of a project whose purpose is to create and validate models able to predict the performance of turbochargers in its working environment. In this paper an extensive experimental study is described, whose main objective is to study the influence of aerodynamic conditions at the compressor inlet on the behaviour of the turbocharger. Laser Doppler anemometry [LDA] and Particle Image velocimetry [PIV] were used for flow investigation upstream of the compressor.