Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Estimation Methodology for Automotive Turbochargers Speed Fluctuations Due to Pulsating Flows

[+] Author and Article Information
Fabrizio Ponti

Department of Industrial Engineering,
University of Bologna,
Via Fontanelle 40,
Forlì 47121, Italy
e-mail: fabrizio.ponti@unibo.it

Vittorio Ravaglioli

Department of Industrial Engineering,
University of Bologna,
Via Fontanelle 40,
Forlì 47121, Italy
e-mail: vittorio.ravaglioli2@unibo.it

Matteo De Cesare

Magneti Marelli Powertrain S.p.A.,
via del Timavo 33,
Bologna 40131, Italy
e-mail: matteo.decesare@magnetimarelli.com

1Corresponding author.

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received May 4, 2015; final manuscript received May 19, 2015; published online July 7, 2015. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(12), 121507 (Jul 07, 2015) (7 pages) Paper No: GTP-15-1155; doi: 10.1115/1.4030839 History: Received May 04, 2015

Turbocharging technique, together with engine downsizing, will play a fundamental role in the near future as a way to reach the required maximum performance while reducing engine displacement and, consequently, CO2 emissions. However, performing an optimal control of the turbocharging system is very difficult, especially for small engines fitted with a low number of cylinders. This is mainly due to the high turbocharger operating range and to the fact that the flow through compressor and turbine is highly unsteady, while only steady-flow maps are usually provided by the manufacturer. In addition, in passenger cars applications, it is usually difficult to optimize turbocharger operating conditions because of the lack of information about pressure/temperature in turbine upstream/downstream circuits and turbocharger rotational speed. This work presents a methodology suitable for instantaneous turbocharger rotational speed determination through a proper processing of the signal coming from an accelerometer mounted on the compressor diffuser or a microphone faced to the compressor. The presented approach can be used to evaluate turbocharger speed mean value and turbocharger speed fluctuation (due to unsteady flow in turbine upstream and downstream circuits), which can be correlated to the power delivered by the turbine. The whole estimation algorithm has been developed and validated for a light-duty turbocharged common-rail diesel engine mounted in a test cell. Nevertheless, the developed methodology is general and can be applied to different turbochargers, both for spark ignited and diesel applications.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.


Bozza, F. , De Bellis, V. , Marelli, S. , and Capobianco, M. , 2011, “1D Simulation and Experimental Analysis of a Turbocharger Compressor for Automotive Engines Under Unsteady Flow Conditions,” SAE Int. J. Engines, 4(1), pp. 1365–1384. [CrossRef]
El Hadef, J. , Colin, G. , Chamaillard, Y. , and Talon, V. , 2012, “Physical-Based Algorithms for Interpolation and Extrapolation of Turbocharger Data Maps,” SAE Int. J. Engines, 5(2), pp. 363–378. [CrossRef]
Marelli, S. , Carraro, C. , and Capobianco, M. , 2012, “Effect of Pulsating Flow Characteristics on Performance and Surge Limit of Automotive Turbocharger Compressors,” SAE Int. J. Engines, 5(2), pp. 596–601. [CrossRef]
Pedersen, T. , Herlufsen, H. , and Hansen, H. , 2005, “Order Tracking in Vibro-Acoustic Measurements: A Novel Approach Eliminating the Tacho Probe,” SAE Technical Paper No. 2005-01-2266.
Cavina, N. , Moro, D. , De Cesare, M. , and Serra, G. , 2008, “Exhaust Gas Turbocharger Speed Measurement Via Acoustic Emission Analysis,” SAE Technical Paper No. 2008-01-1007.
Dehner, R. , Figurella, N. , Selamet, A. , Keller, P. , Becker, M. , Tallio, K. , Miazgowicz, K. , and Wade, R. , 2013, “Instabilities at the Low-Flow Range of a Turbocharger Compressor,” SAE Int. J. Engines, 6(2), pp. 1356–1367. [CrossRef]
Moro, D. , Corti, E. , De Cesare, M. , and Serra, G. , 2009, “Upgrade of a Turbocharger Speed Measurement Algorithm Based on Acoustic Emission,” SAE Technical Paper No. 2009-01-1022.
Ponti, F. , Ravaglioli, V. , Serra, G. , and Stola, F. , 2010, “Instantaneous Engine Speed Measurement and Processing for MFB50 Evaluation,” SAE Int. J. Engines, 2(2), pp. 235–244. [CrossRef]
Ponti, F. , Ravaglioli, V. , Moro, D. , and Serra, G. , 2013, “MFB50 On-Board Estimation Methodology for Combustion Control,” Control Eng. Pract., 21(12), pp. 1821–1829. [CrossRef]


Grahic Jump Location
Fig. 3

Amplitude of turbocharger speed fluctuation for tests run at 2000 rpm and different loads (evaluated using the eddy-current speed sensor)

Grahic Jump Location
Fig. 2

Turbocharger instantaneous speed measured using the eddy-current sensor during a test run at 2000 rpm and bmep = 20 bar

Grahic Jump Location
Fig. 1

Location of the installed sensors

Grahic Jump Location
Fig. 6

Comparison between accelerometer (top plot) and acoustic emission (bottom plot) frequency spectra

Grahic Jump Location
Fig. 7

Compressor characteristic map

Grahic Jump Location
Fig. 8

Inverted compressor map for rough turbo speed estimation

Grahic Jump Location
Fig. 4

Correlations between turbine power and turbocharger rotational speed

Grahic Jump Location
Fig. 5

Correlation between normalized turbine power and the product between the amplitude of turbocharger speed fluctuation and turbo speed mean value

Grahic Jump Location
Fig. 9

Filtered accelerometer spectra for acceleration (top plot) and audio signal (bottom plot)

Grahic Jump Location
Fig. 10

Comparison between measured turbocharger speed (using the eddy-current sensor, blue line) and turbo speed estimated via accelerometer (black line) and audio signal (red dashed line) processing

Grahic Jump Location
Fig. 11

Detailed view of the comparison between measured turbocharger speed (using the eddy-current sensor) and turbo speed estimated via accelerometer (black line) and audio signal (red dashed line) processing

Grahic Jump Location
Fig. 12

Comparison between acquired and filtered accelerometer signal (the selective filter based on fB estimation via spectral analysis has been applied)

Grahic Jump Location
Fig. 13

Falling zero-crossing positions detected (circles) for the filtered accelerometer signal

Grahic Jump Location
Fig. 14

Comparison between measured and estimated instantaneous turbo speed

Grahic Jump Location
Fig. 15

Scheme of the complete instantaneous turbo speed estimation methodology



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In