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Axial turbine design 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 2B-2018.
Abstract

In the process of evaluating a parallel twin-turbine pulseturbocharged concept, the results considering the turbine operation clearly pointed towards an axial type of turbine. The radial turbine design first analyzed was seen to suffer from suboptimum values of flow coefficient, stage loading and blade-speed-ratio. Modifying the radial turbine by both assessing the influence of "trim" and inlet tip diameter all concluded that this type of turbine is limited for the concept. Mainly, the turbine stage was experiencing high values of flow coefficient, requiring a more high flowing type of turbine. Therefore, an axial turbine stage could be feasible as this type of turbine can handle significantly higher flow rates very efficiently. Also,... (More)

In the process of evaluating a parallel twin-turbine pulseturbocharged concept, the results considering the turbine operation clearly pointed towards an axial type of turbine. The radial turbine design first analyzed was seen to suffer from suboptimum values of flow coefficient, stage loading and blade-speed-ratio. Modifying the radial turbine by both assessing the influence of "trim" and inlet tip diameter all concluded that this type of turbine is limited for the concept. Mainly, the turbine stage was experiencing high values of flow coefficient, requiring a more high flowing type of turbine. Therefore, an axial turbine stage could be feasible as this type of turbine can handle significantly higher flow rates very efficiently. Also, the design spectrum is broader as the shape of the turbine blades is not restricted by a radially fibred geometry as in the radial turbine case. In this paper, a single stage axial turbine design is presented. As most turbocharger concepts for automotive and heavy-duty applications are dominated by radial turbines, the axial turbine is an interesting option to be evaluated for pulsecharged concepts. Values of crank-angle-resolved turbine and flow parameters from engine simulations are used as input to the design and subsequent analysis. The data provides a valuable insight into the fluctuating turbine operating conditions and is a necessity for matching a pulse-turbocharged system. Starting on a 1D-basis, the design process is followed through, resulting in a fully defined 3D-geometry. The 3Ddesign is evaluated both with respect to FEA and CFD as to confirm high performance and durability. Turbine maps were used as input to the engine simulation in order to assess this design with respect to "on-engine" conditions and to engine performance. The axial design shows clear advantages with regards to turbine parameters, efficiency and tip speed levels compared to a reference radial design. Improvement in turbine efficiency enhanced the engine performance significantly. The study concludes that the proposed single stage axial turbine stage design is viable for a pulse-turbocharged sixcylinder heavy-duty engine. Taking into account both turbine performance and durability aspects, validation in engine simulations, a highly efficient engine with a practical and realizable turbocharger concept resulted.

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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, Design, Turbine, Turbocharging
host publication
Turbomachinery
volume
2B-2018
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:85054062680
ISBN
9780791851005
DOI
10.1115/GT2018-75453
language
English
LU publication?
yes
id
be36b301-e5b1-48c7-a6ec-a441e18a2e20
date added to LUP
2018-10-24 08:49:13
date last changed
2019-02-20 11:33:10
@inproceedings{be36b301-e5b1-48c7-a6ec-a441e18a2e20,
  abstract     = {<p>In the process of evaluating a parallel twin-turbine pulseturbocharged concept, the results considering the turbine operation clearly pointed towards an axial type of turbine. The radial turbine design first analyzed was seen to suffer from suboptimum values of flow coefficient, stage loading and blade-speed-ratio. Modifying the radial turbine by both assessing the influence of "trim" and inlet tip diameter all concluded that this type of turbine is limited for the concept. Mainly, the turbine stage was experiencing high values of flow coefficient, requiring a more high flowing type of turbine. Therefore, an axial turbine stage could be feasible as this type of turbine can handle significantly higher flow rates very efficiently. Also, the design spectrum is broader as the shape of the turbine blades is not restricted by a radially fibred geometry as in the radial turbine case. In this paper, a single stage axial turbine design is presented. As most turbocharger concepts for automotive and heavy-duty applications are dominated by radial turbines, the axial turbine is an interesting option to be evaluated for pulsecharged concepts. Values of crank-angle-resolved turbine and flow parameters from engine simulations are used as input to the design and subsequent analysis. The data provides a valuable insight into the fluctuating turbine operating conditions and is a necessity for matching a pulse-turbocharged system. Starting on a 1D-basis, the design process is followed through, resulting in a fully defined 3D-geometry. The 3Ddesign is evaluated both with respect to FEA and CFD as to confirm high performance and durability. Turbine maps were used as input to the engine simulation in order to assess this design with respect to "on-engine" conditions and to engine performance. The axial design shows clear advantages with regards to turbine parameters, efficiency and tip speed levels compared to a reference radial design. Improvement in turbine efficiency enhanced the engine performance significantly. The study concludes that the proposed single stage axial turbine stage design is viable for a pulse-turbocharged sixcylinder heavy-duty engine. Taking into account both turbine performance and durability aspects, validation in engine simulations, a highly efficient engine with a practical and realizable turbocharger concept resulted.</p>},
  author       = {Anton, Nicholas and Genrup, Magnus and Fredriksson, Carl and Larsson, Per Inge and Christiansen-Erlandsson, Anders},
  isbn         = {9780791851005},
  keyword      = {Axial,Design,Turbine,Turbocharging},
  language     = {eng},
  location     = {Oslo, Norway},
  publisher    = {American Society of Mechanical Engineers(ASME)},
  title        = {Axial turbine design for a twin-turbine heavy-duty turbocharger concept},
  url          = {http://dx.doi.org/10.1115/GT2018-75453},
  volume       = {2B-2018},
  year         = {2018},
}