面向氢气-柴油双喷射燃烧过程的涡耗散模型参数改进

In order to enhance the predictive accuracy of the traditional eddy dissipation concept(EDC)model for hydrogen-diesel spray collision combustion，this study proposes a dynamic coefficient modification strategy based on the reaction time scales of key fuel components. The approach first computes the characteristic chemical timescales of hydrogen and diesel respectively，and then adjusts the fine-structure vortex model coefficient C_D2 through the local Damköhler number Da to enable regionally adaptive representation of mixing and reaction intensities. As a result，it achieves higher accuracy in predicting the fine-structure vortex mass fraction and the mass exchange rate between turbulent and fine structures. Numerical results show that the original EDC model significantly overestimates the flame lift-off length of the hydrogen jet，while the modified model yields flame lift-off predictions for both hydrogen and diesel that agree better with experimental data. The fine-structure vortex volume predicted by the modified EDC model is in the good agreement with experimental combustion distributions when C_D1 is 0.135. Increasing C_D1 notably reduces the predicted fine-structure vortex volume and weakens the heat release intensity. This study offers a more accurate modeling approach for simulating dual-fuel engine combustion processes involving complex fuel interactions.