Ported Shroud Flow Processes and Their Effect on Turbocharger Compressor Operation

Sidharath Sharma, Martyn Jupp, Ambrose Nickson, John Allport

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

8 Citations (Scopus)

Abstract

The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of the surge by enhancing the aerodynamic stability of the turbocharger compressor. The increase in the stable operation region of the turbocharger compressor is achieved by recirculating the low momentum fluid that blocks the blade passage to the compressor inlet through a ported shroud cavity. While the ported shroud design delays surge, it comes with a small penalty in efficiency.
This work presents an investigation of the flow processes associated with a ported shroud compressor and quantifies the effect of these flow mechanisms on the compressor operation. The full compressor stage is numerically modelled using a Reynolds Averaged Navier-Stokes (RANS) approach employing the shear stress transport (SST) turbulence model for steady state simulations at the design and near surge conditions. The wheel rotation is modelled using a multiple reference frame (MRF) approach. The results show that the flow exits the PS cavity at the near surge condition in the form of three jet-like structures of varying velocity amplitudes. Net entropy generation in the compressor model is used to assess the influence of the ported shroud design on the compressor losses, and the results indicate a small Inlet-PS mixing region is the primary source of entropy generation in the near surge conditions. The analysis also explores the trends of entropy generation at the design and the near surge condition across the different speed lines. The results show that the primary source of entropy generation is the impeller region for the design condition and the inlet-PS cavity region for the near surge condition.
Original languageEnglish
Title of host publicationASME Turbo Expo 2017
Subtitle of host publicationTurbomachinery Technical Conference and Exposition
PublisherAmerican Society of Mechanical Engineers (ASME)
Number of pages13
Volume2C: Turbomachinery
ISBN (Print)9780791850800
DOIs
Publication statusPublished - 2017
EventAmerican Society of Engineers Turbo-Expo: Turbomachinery Technical Conference & Exposition - Charlotte, United States
Duration: 26 Jun 201730 Jun 2017

Conference

ConferenceAmerican Society of Engineers Turbo-Expo
Abbreviated titleASME
CountryUnited States
CityCharlotte
Period26/06/1730/06/17

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Sharma, S., Jupp, M., Nickson, A., & Allport, J. (2017). Ported Shroud Flow Processes and Their Effect on Turbocharger Compressor Operation. In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition (Vol. 2C: Turbomachinery). [V02CT44A017] American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/GT2017-63678