The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications

Sam Lee, Ahmed Rezk, Mrtin Jupp, Keith Nickson

Research output: Contribution to journalArticle

Abstract

Engine downsizing allows automotive manufactures to achieve improved efficiency and reduce emissions. Turbocharging can increase the power density of the engine, and therefore plays a vital role in downsizing. Due to the nature of the reciprocating engine, a turbocharger turbine operates in a highly unsteady environment. This paper presents a computational investigation looking at the impact of pulse shape on the performance of a mixed flow turbine for turbocharger applications. While the impact of pulse frequency and amplitude on turbine unsteady performance has received significant attention in the past, little work has been done on the impact of the pulse shape. In the current study, four inlet pulse shapes have been investigated and shown to have a significant impact on turbine instantaneous performance, where efficiency and mass flow hysteresis varied significantly between test cases. This result shows for in-depth analyses of turbine flow physics and loss mechanisms, accurately modelling the inlet pulse shape is vital. The square pulse showed the most distinct impact with normalized cycle average efficiency decreasing by 1.37% and a 2.23% reduction in normalized stage MFP when compared to the sinusoidal wave. The variation in normalized cycle averaged stage efficiency was found to be less than 0.25% for the remaining three wave forms and the variation in normalized cycle averaged MFP less than 0.5%. This finding suggests that a simple sinusoidal wave form can be used for the majority of cycle-averaged performance comparisons.
Original languageEnglish
Pages (from-to)136-142
Number of pages7
JournalInternational Journal of Mechanical Engineering and Robotics Research
Volume7
Issue number2
DOIs
Publication statusPublished - 1 Mar 2018

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Turbines
Engines
Hysteresis
Physics

Bibliographical note

Copyright © 2016-2017 International Journal of Mechanical Engineering and Robotics Research, All Rights Reserved

Keywords

  • pulsating turbine flow
  • CFD
  • pulse shape

Cite this

Lee, S., Rezk, A., Jupp, M., & Nickson, K. (2018). The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications. International Journal of Mechanical Engineering and Robotics Research, 7(2), 136-142. https://doi.org/10.18178/ijmerr.7.2.136-142
Lee, Sam ; Rezk, Ahmed ; Jupp, Mrtin ; Nickson, Keith. / The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications. In: International Journal of Mechanical Engineering and Robotics Research. 2018 ; Vol. 7, No. 2. pp. 136-142.
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abstract = "Engine downsizing allows automotive manufactures to achieve improved efficiency and reduce emissions. Turbocharging can increase the power density of the engine, and therefore plays a vital role in downsizing. Due to the nature of the reciprocating engine, a turbocharger turbine operates in a highly unsteady environment. This paper presents a computational investigation looking at the impact of pulse shape on the performance of a mixed flow turbine for turbocharger applications. While the impact of pulse frequency and amplitude on turbine unsteady performance has received significant attention in the past, little work has been done on the impact of the pulse shape. In the current study, four inlet pulse shapes have been investigated and shown to have a significant impact on turbine instantaneous performance, where efficiency and mass flow hysteresis varied significantly between test cases. This result shows for in-depth analyses of turbine flow physics and loss mechanisms, accurately modelling the inlet pulse shape is vital. The square pulse showed the most distinct impact with normalized cycle average efficiency decreasing by 1.37{\%} and a 2.23{\%} reduction in normalized stage MFP when compared to the sinusoidal wave. The variation in normalized cycle averaged stage efficiency was found to be less than 0.25{\%} for the remaining three wave forms and the variation in normalized cycle averaged MFP less than 0.5{\%}. This finding suggests that a simple sinusoidal wave form can be used for the majority of cycle-averaged performance comparisons.",
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Lee, S, Rezk, A, Jupp, M & Nickson, K 2018, 'The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications', International Journal of Mechanical Engineering and Robotics Research, vol. 7, no. 2, pp. 136-142. https://doi.org/10.18178/ijmerr.7.2.136-142

The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications. / Lee, Sam; Rezk, Ahmed; Jupp, Mrtin; Nickson, Keith.

In: International Journal of Mechanical Engineering and Robotics Research, Vol. 7, No. 2, 01.03.2018, p. 136-142.

Research output: Contribution to journalArticle

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T1 - The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications

AU - Lee, Sam

AU - Rezk, Ahmed

AU - Jupp, Mrtin

AU - Nickson, Keith

N1 - Copyright © 2016-2017 International Journal of Mechanical Engineering and Robotics Research, All Rights Reserved

PY - 2018/3/1

Y1 - 2018/3/1

N2 - Engine downsizing allows automotive manufactures to achieve improved efficiency and reduce emissions. Turbocharging can increase the power density of the engine, and therefore plays a vital role in downsizing. Due to the nature of the reciprocating engine, a turbocharger turbine operates in a highly unsteady environment. This paper presents a computational investigation looking at the impact of pulse shape on the performance of a mixed flow turbine for turbocharger applications. While the impact of pulse frequency and amplitude on turbine unsteady performance has received significant attention in the past, little work has been done on the impact of the pulse shape. In the current study, four inlet pulse shapes have been investigated and shown to have a significant impact on turbine instantaneous performance, where efficiency and mass flow hysteresis varied significantly between test cases. This result shows for in-depth analyses of turbine flow physics and loss mechanisms, accurately modelling the inlet pulse shape is vital. The square pulse showed the most distinct impact with normalized cycle average efficiency decreasing by 1.37% and a 2.23% reduction in normalized stage MFP when compared to the sinusoidal wave. The variation in normalized cycle averaged stage efficiency was found to be less than 0.25% for the remaining three wave forms and the variation in normalized cycle averaged MFP less than 0.5%. This finding suggests that a simple sinusoidal wave form can be used for the majority of cycle-averaged performance comparisons.

AB - Engine downsizing allows automotive manufactures to achieve improved efficiency and reduce emissions. Turbocharging can increase the power density of the engine, and therefore plays a vital role in downsizing. Due to the nature of the reciprocating engine, a turbocharger turbine operates in a highly unsteady environment. This paper presents a computational investigation looking at the impact of pulse shape on the performance of a mixed flow turbine for turbocharger applications. While the impact of pulse frequency and amplitude on turbine unsteady performance has received significant attention in the past, little work has been done on the impact of the pulse shape. In the current study, four inlet pulse shapes have been investigated and shown to have a significant impact on turbine instantaneous performance, where efficiency and mass flow hysteresis varied significantly between test cases. This result shows for in-depth analyses of turbine flow physics and loss mechanisms, accurately modelling the inlet pulse shape is vital. The square pulse showed the most distinct impact with normalized cycle average efficiency decreasing by 1.37% and a 2.23% reduction in normalized stage MFP when compared to the sinusoidal wave. The variation in normalized cycle averaged stage efficiency was found to be less than 0.25% for the remaining three wave forms and the variation in normalized cycle averaged MFP less than 0.5%. This finding suggests that a simple sinusoidal wave form can be used for the majority of cycle-averaged performance comparisons.

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Lee S, Rezk A, Jupp M, Nickson K. The Influence of Pulse Shape on the Performance of a Mixed Flow Turbine for Turbocharger Applications. International Journal of Mechanical Engineering and Robotics Research. 2018 Mar 1;7(2):136-142. https://doi.org/10.18178/ijmerr.7.2.136-142