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Active control turbocharger for enhanced power recovery

Researchers from Universiti Teknologi Malaysia and Imperial College London have designed an active control turbocharger consisting of a mixed-flow turbine with pivoting nozzle vanes to adapt to the pulsating exhaust flow. In a paper published in the International Journal of Engine Research, they suggest that the turbocharger has strong potential to improve engine performance in parts of the operational envelope, which need to be further harnessed for real-life applications.

They tested the turbocharger at an equivalent speed of 48,000 rpm with inlet flow pulsation of 40 and 60 Hz, which corresponds to a four-stroke diesel engine speed of 1600 and 2400 r/min, respectively.

The nozzle vane operating schedules for each pulse period were evaluated experimentally in two general modes: natural opening and closing of the vanes due to the pulsating flow and the forced sinusoidal oscillation of the vanes to match the incoming pulsating flow.

Results of their study showed that engine power increased by between 3.58% and 7.76% between 800 and 1400 rpm.


  • Srithar Rajoo, Apostolos Pesiridis, Ricardo Martinez-Botas (2013) Novel Method to Improve Engine Exhaust Energy Extraction with Active Control Turbocharger. International Journal of Engine Research doi: 10.1177/1468087412472414


Trevor Carlson

Picture of CAD model of design available at -


Interesting but do the vanes always flutter (at ~ 100Hz), or only for acceleration?

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