The sensitivity study of a mechanical loss model in turbocharger system

Haizhu Wang, Richard Burke, Colin Copeland

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

Abstract

3D modelling can be a very useful tool for optimising the design of turbocharger turbines. However, it is difficult to achieve high levels of correlation with experimental data which can undermine confidence in the 3D model results. A key difference between modelling and experiments is the way turbine efficiency is estimated: in CFD this is estimated directly from the shaft torque created by the turbine, however in experiments this is usually estimated based on the enthalpy rise measured at the compressor. This means that there is an inherent offset between the two which is the mechanical losses of the bearing system used to support the connecting shaft. The accuracy of the mechanical loss estimate can therefore play a critical role in the correlation of 3D modelling with experiments. A 3D CFD model of a turbocharger turbine of a 1.5L gasoline engine has been coupled with a 0D mechanical losses model. The model comprises of seven parameters that characterise the bearing losses such as oil film thickness, bearing surface finish and clearances. A sensitivity study is conducted on these parameters to understand which are the critical aspects that should be parameterised and what relationship these parameters may have with the operating state of the turbocharger (shaft speed, shaft torque etc.). Experimental measurements were conducted for the same turbocharger to provide a baseline for assessing the impact of the mechanical losses model. These provide the boundary conditions to the CFD by ignoring the effects of heat transfer, and the results were compared to the 3D simulation results.

Original languageEnglish
Title of host publicationASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020
PublisherThe American Society of Mechanical Engineers(ASME)
ISBN (Electronic)9780791884034
DOIs
Publication statusE-pub ahead of print - 14 Dec 2020
EventASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020 - Virtual, Online
Duration: 4 Nov 20206 Nov 2020

Publication series

NameASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020

Conference

ConferenceASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020
CityVirtual, Online
Period4/11/206/11/20

ASJC Scopus subject areas

  • Fuel Technology
  • Automotive Engineering
  • Mechanical Engineering

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