Olivier Orfila: Senior researcher, IFSTTAR, France


One month in China as Invited professor

O. Orfila

Accompanied by his famous colleague J. Ehrlich and boss D. Gruyer, I will work on an important chinese project at the Shanghai TongJi University for whole month of September.

My last publication

Experimental testing and simulations of speed variations impact on fuel consumption of conventional gasoline passenger cars

Transportation Research Part D: Transport and Environment

C. Freitas Salgueiredo, O. Orfila, G. Saint Pierre, P. Doublet, S. Glaser S. Doncieux, V. Billat

Speed variations are considered as an alternative for reducing fuel consumption during the use phase of passenger cars. It explores vehicle engine operating zones with lower fuel consumption, thus making possible a reduction in fuel consumption when compared to constant speed operation. In this paper, we present an evaluation of two conditions of speed variations: 50–70?km/h and 90–110?km/h using numerical simulations and controlled tests. The controlled tests performed on a test track by a professional pilot show that a reduction in fuel consumption is achievable with a conventional gasoline passenger car, with no adaptations for realizing speed variations. Numerical simulations based on a backward quasi-static powertrain model are used to evaluate the potential of speed variations for reducing fuel consumption in other speed variation conditions. When deceleration is performed with gear in neutral position, simulations show that speed variations are always correlated to a lower fuel consumption. This was suspected through previous numerical tests or evaluation on test bench but not in controlled tests conditions.

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