Effects of VNT and IGV association on turbocharger centrifugal compressor performances

Turbochargers are today widely used to improve performances of internal combustion engines. The compressor's characteristics are important because they govern the fresh air quantity introduced to engine cylinder and consequently determine the air/fuel ratio which governs the combustion quality. Generally, the best engine turbocharger matching is achieved by using the variable geometry technique. This paper studies the effects of VNT (Variable Nozzle Turbine) and IGV (Inlet Guide Vanes) combination on compressor's characteristics. However, except the industrial compressor cases, the flow direction adjustment at the entry of automotive compressor is not yet applied in spite of the high rotational speed. An experi mental investigation coupled with a numerical study is used to achieve this work. The IGV technique shows a real improvement of the compressor's characteristics over its whole operating range but without adjusting the look of the efficiency curve at large opening of turbine nozzle blades because power and diffuser loses remain important. http://dx.doi.org/10.5755/j01.mech.17.2.332

[1]  A. H. Abdullah,et al.  The Performance of a Centrifugal Compressor With High Inlet Prewhirl , 1998 .

[2]  Walter Knecht,et al.  Diesel engine development in view of reduced emission standards , 2008 .

[3]  H. Simon,et al.  Improvements in Performance Characteristics of Single-Stage and Multistage Centrifugal Compressors by Simultaneous Adjustments of Inlet Guide Vanes and Diffuser Vanes , 1987 .

[4]  I. Ariga,et al.  Inducer Stall in a Centrifugal Compressor With Inlet Distortion , 1987 .

[5]  F. J. Wallace,et al.  Experimental and Theoretical Performance of a Radial Flow Turbocharger Compressor with Inlet Prewhirl , 1975 .

[6]  Hiroshi Uchida,et al.  Effects of Variable Inlet Guide Vanes on Small Centrifugal Compressor Performance , 1999 .

[7]  C. Rodgers,et al.  Impeller Stalling as Influenced by Diffusion Limitations , 1977 .

[8]  Agostino Gambarotta,et al.  Variable Geometry and Waste-Gated Automotive Turbochargers: Measurements and Comparison of Turbine Performance , 1992 .

[9]  Sanford Fleeter,et al.  Off-Design Transonic Rotor-Inlet Guide Vane Unsteady Aerodynamic Interactions , 2005 .

[10]  Akinobu Kashimoto,et al.  Development of Wide Flow Range Compressor with Variable Inlet Guide Vane , 2006 .

[12]  Nicolas Binder,et al.  Influence of a variable guide vane nozzle on the design parameters of a radial turbine stage , 2005 .

[13]  Yousef S. H. Najjar,et al.  Effect of Prewhirl on the Performance of Centrifugal Compressors , 2002 .

[14]  C. Rodgers,et al.  A Diffusion Factor Correlation for Centrifugal Impeller Stalling , 1978 .