Quantitative measurements of preferential evaporation effects of multicomponent gasoline fuels sprays at ECN Spray G conditions

Matthieu Cordier (1, 2) , Lama Itani (1, 2) , Gilles Bruneaux (1, 2)

1 IFPEN - IFP Energies nouvelles
2 Institut Carnot IFPEN Transports Energie

A Two Tracers Laser-Induced Fluorescence (2 TLIF) technique is used to quantify the effects of preferential evaporation of multi-component fuels on the fuel component distribution. The technique is based on the simultaneous detection of the fluorescence of two aromatic tracers with complementary evaporation characteristics matched to different components of a multi-component fuel. Relative variations in the spatial distribution of tracer distribution as a consequence of preferential evaporation are determined from the ratio of LIF-signals measured within two distinct spectral bands. A thermodynamic model is then used to relate the ratio map with the fuel component map. The accuracy and precision of the method are characterized from determining the LIF-signal ratio within two identical spectral bands. Measurements are performed in a high-pressure high-temperature vessel equipped with a 8 holes injector. The ECN Spray G target conditions are chosen as reference conditions at injection. The only difference with these target conditions is the use of a multicomponent surrogate fuel. Parametric variations around these target conditions are also performed in order to investigate their effect on the preferential evaporation effect. The ambient temperature is varied between 525 and 625K and the injection pressure is reduced from 200 to 100bar. The impact of ethanol addition is also study with two different fuel mixtures in addition to the reference surrogate fuel: E20 and E85 which feature 20 and 85% of pure ethanol within surrogate, respectively. A significant preferential evaporation effect is observed in this condition representative of engine applications, and results in a spatial segregation between low and high volatility fuel components, respectively at the tail and tip of the plumes. This effect is enhanced by the addition of ethanol, the decrease of ambient temperature and of injection pressure.

Mots clés: Multi-component fuels; ECN; Spray G; gasoline sprays; preferential evaporation; laser- induced fluorescence; E20; E85

Domaines: Sciences de l'ingénieur [physics]

Matthieu Cordier, Lama Itani, Gilles Bruneaux. Quantitative measurements of preferential evaporation effects of multicomponent gasoline fuels sprays at ECN Spray G conditions. International Journal of Engine Research, 2020, 21 (1), pp.185-198. ⟨10.1177/1468087419838391⟩. ⟨hal-02505308⟩