A convenient way of modelling turbochargers is based on data maps. These models are easy to put into place, require low CPU charge and are control-oriented. Data relative to compressor and turbine are read from tables: pressure ratio and efficiency are determined as functions of mass flow rate and rotary speed on two distinct data maps. Nevertheless, this type of model has drawbacks:• Usually, only higher turbocharger speed data are mapped (> 90000 rpm ) although the low rpm zone is the most useful zone for normalized driving cycles simulations. Moreover, maps are poorly discretized, leading to the use of specific extra-interpolation methods (many are identified in [5]).• These methods are purely mathematical, which gives inaccurate results in extrapolation zones. Relation between pressure ratio and efficiency is then broken (i.e., if one implements a pumping model for the compressor, the pressure ratio will be affected, but not the efficiency).The present paper develops a new extra/interpolation model incorporating physical laws. An analysis of turbomachinery equations is performed. A new approach for extra-interpolating performance maps, which satisfies the physical laws stated in turbomachinery equations, is derived from this work. Results from this new model are compared with standard methods.The major conclusions drawn from this study are: 1 -The new model improves the simulation accuracy while keeping the same easiness of use and robustness. 2 -Extrapolation in the low rpm zone is derived from physical equations. 3 -This method is applicable to both compressor and turbine. 4 -The pressure ratio and efficiency maps are now linked.

New experimental results were obtained to better assess the effect of ozone on the burning velocity of premixed methane–air flames at atmospheric pressure and room temperature. Ozone was produced using a dielectric barrier discharge device, and its quantity was fixed equal to 5 g/Nm3 in air (2369 ppm of ozone). Measurements were performed using a Bunsen burner. Simultaneous to flame height measurements, a 1D Rayleigh scattering system was set up to investigate the impact of ozone on the thermal flame structure. The experimental results showed that the partial conversion of molecular oxygen into ozone has a moderate positive effect on the burning velocity of methane–air flames, confirming previous measurements in the literature. The injection of 5 g/Nm3 of ozone in air increased the burning velocities by ca. 0.8–1.3 cm/s (ca. 3–8%). The oxidation of methane in the presence or absence of ozone was modeled using a detailed chemical kinetic scheme taken from the literature, to which an ozone submechanism was added. The computations agreed well with the present set of experimental data and represented the trends previously reported in the literature. Kinetic modeling was used to rationalize the present results and predicts increasing burning velocities with increasing air ozonization.

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