Meanline Modeling of Ported Shroud Turbocharger Compressor

Abstract

The requirements for higher fuel economy and better diesel and gasoline engines demand a wider range in turbocharger compressor operation. Ported shroud compressor housing is one of the most commonly used techniques for compressor map width enhancement. Although the general mechanism of such a flow feature is well understood, there are no readily available design tools to guide the engineers at the preliminary design stage. Designers have had to rely on three-dimensional (3D) CFD tools to sort out many design variables, but these tools can be prohibitively expensive. This paper explains how to develop a ported shroud compressor model on top of a commercial meanline compressor design program. The model considers some basic parameters, such as bleed location and geometry, which drive the recirculation or bypass flow through the bleed channel. The effects of the secondary flow on the compressor performance, such as pressure rise, efficiency, and stall and choke margins are also analyzed. The model prediction is validated with CFD simulation and test data.