Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine

Samuel Lee, Simon Barrans, Martyn Jupp, Ambrose Nickson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. A turbocharger increases charge air density using a turbine to extract waste energy from the exhaust gas to drive a compressor.
Most turbocharger applications employ a radial inflow turbine. However, to ensure radial stacking of the blade fibers and avoid excessive blade stresses, the inlet blade angle must remain at zero degrees. Alternately, mixed flow turbines can offer non-zero blade angles while maintaining radial stacking of the blade fibers. The additional freedom to manipulate the blade leading edge and varying tip speed allow for varying leading edge incidence in the span-wise direction. Furthermore, the flow development in the volute does not necessarily lead to uniform inlet conditions.
The current paper investigates the performance of a mixed flow rotor passage under a range of span-wise flow distributions including that produced by a turbine volute. Initial unsteady pulsating simulations were conducted and the volute exit flows extracted. These distributions were then applied as boundary conditions to a single passage model. All simulations were carried out at a constant MFP and average leading edge relative flow angle.
It was observed that the different inlet flow distributions resulted in marked difference in passage flow characteristics. A 2.17% variation was observed between cases in the radial passage. A tilted passage was also included providing an increased axial flow component at the inlet. This passage was found to result in greater swallowing capacity when compared to that of the radial passage.
Original languageEnglish
Title of host publicationASME Turbo Expo 2018
Subtitle of host publicationTurbomachinery Technical Conference and Exposition
PublisherAmerican Society of Mechanical Engineers (ASME)
Number of pages12
Volume2B-2018
ISBN (Electronic)9780791851005
ISBN (Print)9780791851005
DOIs
Publication statusPublished - 11 Jun 2018
EventAmerican Society of Mechanical Engineers Turbo Expo: Turbomachinery Technical Conference & Exposition - Norway Exhibition and Convention Centre , Lillestrøm, Norway
Duration: 11 Jun 201815 Jun 2018
https://www.asme.org/events/turbo-expo?_ga=2.121019592.1354562119.1526998905-718050275.1526998905 (Link to Conference Website )

Conference

ConferenceAmerican Society of Mechanical Engineers Turbo Expo
CountryNorway
CityLillestrøm
Period11/06/1815/06/18
Internet address

Fingerprint

Turbines
Engines
Inlet flow
Fibers
Axial flow
Exhaust gases
Automotive industry
Turbomachine blades
Compressors
Rotors
Boundary conditions
Air

Cite this

Lee, S., Barrans, S., Jupp, M., & Nickson, A. (2018). Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine. In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition (Vol. 2B-2018). [GT2018-76992] American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/GT2018-76992
Lee, Samuel ; Barrans, Simon ; Jupp, Martyn ; Nickson, Ambrose. / Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine. ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. Vol. 2B-2018 American Society of Mechanical Engineers (ASME), 2018.
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title = "Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine",
abstract = "Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. A turbocharger increases charge air density using a turbine to extract waste energy from the exhaust gas to drive a compressor. Most turbocharger applications employ a radial inflow turbine. However, to ensure radial stacking of the blade fibers and avoid excessive blade stresses, the inlet blade angle must remain at zero degrees. Alternately, mixed flow turbines can offer non-zero blade angles while maintaining radial stacking of the blade fibers. The additional freedom to manipulate the blade leading edge and varying tip speed allow for varying leading edge incidence in the span-wise direction. Furthermore, the flow development in the volute does not necessarily lead to uniform inlet conditions. The current paper investigates the performance of a mixed flow rotor passage under a range of span-wise flow distributions including that produced by a turbine volute. Initial unsteady pulsating simulations were conducted and the volute exit flows extracted. These distributions were then applied as boundary conditions to a single passage model. All simulations were carried out at a constant MFP and average leading edge relative flow angle. It was observed that the different inlet flow distributions resulted in marked difference in passage flow characteristics. A 2.17{\%} variation was observed between cases in the radial passage. A tilted passage was also included providing an increased axial flow component at the inlet. This passage was found to result in greater swallowing capacity when compared to that of the radial passage.",
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Lee, S, Barrans, S, Jupp, M & Nickson, A 2018, Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine. in ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. vol. 2B-2018, GT2018-76992, American Society of Mechanical Engineers (ASME), American Society of Mechanical Engineers Turbo Expo, Lillestrøm, Norway, 11/06/18. https://doi.org/10.1115/GT2018-76992

Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine. / Lee, Samuel; Barrans, Simon; Jupp, Martyn; Nickson, Ambrose.

ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. Vol. 2B-2018 American Society of Mechanical Engineers (ASME), 2018. GT2018-76992.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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T1 - Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine

AU - Lee, Samuel

AU - Barrans, Simon

AU - Jupp, Martyn

AU - Nickson, Ambrose

PY - 2018/6/11

Y1 - 2018/6/11

N2 - Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. A turbocharger increases charge air density using a turbine to extract waste energy from the exhaust gas to drive a compressor. Most turbocharger applications employ a radial inflow turbine. However, to ensure radial stacking of the blade fibers and avoid excessive blade stresses, the inlet blade angle must remain at zero degrees. Alternately, mixed flow turbines can offer non-zero blade angles while maintaining radial stacking of the blade fibers. The additional freedom to manipulate the blade leading edge and varying tip speed allow for varying leading edge incidence in the span-wise direction. Furthermore, the flow development in the volute does not necessarily lead to uniform inlet conditions. The current paper investigates the performance of a mixed flow rotor passage under a range of span-wise flow distributions including that produced by a turbine volute. Initial unsteady pulsating simulations were conducted and the volute exit flows extracted. These distributions were then applied as boundary conditions to a single passage model. All simulations were carried out at a constant MFP and average leading edge relative flow angle. It was observed that the different inlet flow distributions resulted in marked difference in passage flow characteristics. A 2.17% variation was observed between cases in the radial passage. A tilted passage was also included providing an increased axial flow component at the inlet. This passage was found to result in greater swallowing capacity when compared to that of the radial passage.

AB - Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. A turbocharger increases charge air density using a turbine to extract waste energy from the exhaust gas to drive a compressor. Most turbocharger applications employ a radial inflow turbine. However, to ensure radial stacking of the blade fibers and avoid excessive blade stresses, the inlet blade angle must remain at zero degrees. Alternately, mixed flow turbines can offer non-zero blade angles while maintaining radial stacking of the blade fibers. The additional freedom to manipulate the blade leading edge and varying tip speed allow for varying leading edge incidence in the span-wise direction. Furthermore, the flow development in the volute does not necessarily lead to uniform inlet conditions. The current paper investigates the performance of a mixed flow rotor passage under a range of span-wise flow distributions including that produced by a turbine volute. Initial unsteady pulsating simulations were conducted and the volute exit flows extracted. These distributions were then applied as boundary conditions to a single passage model. All simulations were carried out at a constant MFP and average leading edge relative flow angle. It was observed that the different inlet flow distributions resulted in marked difference in passage flow characteristics. A 2.17% variation was observed between cases in the radial passage. A tilted passage was also included providing an increased axial flow component at the inlet. This passage was found to result in greater swallowing capacity when compared to that of the radial passage.

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DO - 10.1115/GT2018-76992

M3 - Conference contribution

SN - 9780791851005

VL - 2B-2018

BT - ASME Turbo Expo 2018

PB - American Society of Mechanical Engineers (ASME)

ER -

Lee S, Barrans S, Jupp M, Nickson A. Investigation into the impact of span-wise flow distribution on the performance of a mixed flow turbine. In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. Vol. 2B-2018. American Society of Mechanical Engineers (ASME). 2018. GT2018-76992 https://doi.org/10.1115/GT2018-76992