The Sensitivity Study of a Mechanical Loss Model in Turbocharger System

2020 ◽

Author(s):

Haizhu Wang ◽

Richard Burke ◽

Colin Copeland

Keyword(s):

Gasoline Engine ◽

Critical Role ◽

Sensitivity Study ◽

3D Modelling ◽

Mechanical Loss ◽

Turbine Efficiency ◽

Shaft Torque ◽

The Impact ◽

Loss Estimate ◽

Critical Aspects

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.

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Electrified Drive-Unit Parametric Mechanical-Loss Model Development and Calibration

10.4271/2019-01-1298 ◽

2019 ◽

Author(s):

Goro Tamai ◽

Sairanga Palaparthy ◽

Bruce Wang ◽

Ralph Ilunga

Keyword(s):

Model Development ◽

Mechanical Loss ◽

Drive Unit ◽

Loss Model

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Analytical Mechanical Loss Model for Planetary Gearset

10.4271/2015-01-1090 ◽

2015 ◽

Cited By ~ 1

Author(s):

Sachin Bhide

Keyword(s):

Mechanical Loss ◽

Loss Model

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Race Difference in Auditory Sensitivity

Journal of Speech and Hearing Research ◽

10.1044/jshr.0704.389 ◽

1964 ◽

Vol 7 (4) ◽

pp. 389-393 ◽

Cited By ~ 3

Author(s):

David C. Shepherd ◽

Robert Goldstein ◽

Benjamin Rosenblüt

Keyword(s):

White Women ◽

White Men ◽

Sensitivity Study ◽

Auditory Sensitivity ◽

Race Difference ◽

Men And Women ◽

Auditory Thresholds ◽

Békésy Audiometry ◽

Method Of Adjustment ◽

Better Than

Two separate studies investigated race and sex differences in normal auditory sensitivity. Study I measured thresholds at 500, 1000, and 2000 cps of 23 white men, 26 white women, 21 negro men, and 24 negro women using the method of limits. In Study II thresholds of 10 white men, 10 white women, 10 negro men, and 10 negro women were measured at 1000 cps using four different stimulus conditions and the method of adjustment by means of Bekesy audiometry. Results indicated that the white men and women in Study I heard significantly better than their negro counterparts at 1000 and 2000 cps. There were no significant differences between the average thresholds measured at 1000 cps of the white and negro men in Study II. White women produced better auditory thresholds with three stimulus conditions and significantly more sensitive thresholds with the slow pulsed stimulus than did the negro women in Study II.

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