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On the choice of turbine type for a twin-turbine heavy-duty turbocharger concept

Anton, Nicholas; Genrup, Magnus LU ; Fredriksson, Carl; Larsson, Per Inge and Christiansen-Erlandsson, Anders (2018) ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition, GT 2018 8.
Abstract

In this study, a fundamental approach to the choice of turbocharger turbine for a pulse-charged heavy-duty diesel engine is presented. A standard six-cylinder engine build with a production exhaust manifold and a Twin-scroll turbocharger is used as a baseline case. The engine exhaust configuration is redesigned and evaluated in engine simulations for a pulse-charged concept consisting of a parallel twin-turbine layout. This concept will allow for pulse separation with minimized exhaust pulse interference and low exhaust manifold volume. This turbocharger concept is uncommon, as most previous studies have considered two stage systems, various multiple entry turbine stages etc. Even more rare is the fundamental aspect regarding the choice... (More)

In this study, a fundamental approach to the choice of turbocharger turbine for a pulse-charged heavy-duty diesel engine is presented. A standard six-cylinder engine build with a production exhaust manifold and a Twin-scroll turbocharger is used as a baseline case. The engine exhaust configuration is redesigned and evaluated in engine simulations for a pulse-charged concept consisting of a parallel twin-turbine layout. This concept will allow for pulse separation with minimized exhaust pulse interference and low exhaust manifold volume. This turbocharger concept is uncommon, as most previous studies have considered two stage systems, various multiple entry turbine stages etc. Even more rare is the fundamental aspect regarding the choice of turbine type as most manufacturers tend to focus on radial turbines, which by far dominate the turbochargers of automotive and heavy-duty applications. By characterizing the turbine operation with regards to turbine parameters for optimum performance found in literature a better understanding of the limitations of turbine types can be achieved. A compact and low volume exhaust manifold design is constructed for the turbocharger concept and the reference radial turbine map is scaled in engine simulations to a pre-set AFRtarget at a low engine RPM. By obtaining crank-angle-resolved data from engine simulations, key turbine parameters are studied with regard to the engine exhaust pulse-train. At the energetic exhaust pressure pulse peak, the reference radial turbine is seen to operate with suboptimum values of Blade-Speed-Ratio, Stage Loading and Flow Coefficient. The study concludes that in order to achieve high turbine efficiency for this pulse-charged turbocharger concept, a turbine with efficiency optimum towards low Blade-Speed Ratios, high Stage Loading and high Flow Coefficient is required. An axial turbine of low degree of reaction-design could be viable in this respect.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Axial, Radial, Turbine, Turbocharging
host publication
ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition
volume
8
publisher
American Society of Mechanical Engineers(ASME)
conference name
ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition, GT 2018
conference location
Oslo, Norway
conference dates
2018-06-11 - 2018-06-15
external identifiers
  • scopus:85053929818
ISBN
9780791851173
DOI
10.1115/GT201875452
language
English
LU publication?
yes
id
2ed460d8-e44d-4362-9cc4-3e04a29050a4
date added to LUP
2018-10-24 09:06:58
date last changed
2019-01-06 14:12:03
@inproceedings{2ed460d8-e44d-4362-9cc4-3e04a29050a4,
  abstract     = {<p>In this study, a fundamental approach to the choice of turbocharger turbine for a pulse-charged heavy-duty diesel engine is presented. A standard six-cylinder engine build with a production exhaust manifold and a Twin-scroll turbocharger is used as a baseline case. The engine exhaust configuration is redesigned and evaluated in engine simulations for a pulse-charged concept consisting of a parallel twin-turbine layout. This concept will allow for pulse separation with minimized exhaust pulse interference and low exhaust manifold volume. This turbocharger concept is uncommon, as most previous studies have considered two stage systems, various multiple entry turbine stages etc. Even more rare is the fundamental aspect regarding the choice of turbine type as most manufacturers tend to focus on radial turbines, which by far dominate the turbochargers of automotive and heavy-duty applications. By characterizing the turbine operation with regards to turbine parameters for optimum performance found in literature a better understanding of the limitations of turbine types can be achieved. A compact and low volume exhaust manifold design is constructed for the turbocharger concept and the reference radial turbine map is scaled in engine simulations to a pre-set AFRtarget at a low engine RPM. By obtaining crank-angle-resolved data from engine simulations, key turbine parameters are studied with regard to the engine exhaust pulse-train. At the energetic exhaust pressure pulse peak, the reference radial turbine is seen to operate with suboptimum values of Blade-Speed-Ratio, Stage Loading and Flow Coefficient. The study concludes that in order to achieve high turbine efficiency for this pulse-charged turbocharger concept, a turbine with efficiency optimum towards low Blade-Speed Ratios, high Stage Loading and high Flow Coefficient is required. An axial turbine of low degree of reaction-design could be viable in this respect.</p>},
  author       = {Anton, Nicholas and Genrup, Magnus and Fredriksson, Carl and Larsson, Per Inge and Christiansen-Erlandsson, Anders},
  isbn         = {9780791851173},
  keyword      = {Axial,Radial,Turbine,Turbocharging},
  language     = {eng},
  location     = {Oslo, Norway},
  publisher    = {American Society of Mechanical Engineers(ASME)},
  title        = {On the choice of turbine type for a twin-turbine heavy-duty turbocharger concept},
  url          = {http://dx.doi.org/10.1115/GT201875452},
  volume       = {8},
  year         = {2018},
}