To evaluate the effective mixture composition in a direct-injection spark-ignition (DISI) engine, a numerical simulation was developed incorporating models for fuel injection, primary and secondary liquid fuel breakup and evaporation. The primary objective is to assess the fuel evaporation state prior to combustion - a critical factor influencing heat release and pollutant formation. The Wave-Breakup Model was employed for simulating the primary breakup of liquid fuel into droplets, providing input to the Arcoumanis model for secondary breakup. A chi-squared distribution was applied to model the distribution of Sauter Mean Diameters (SMD) of the resulting atomized droplets, while breakup time parameters were derived directly from the breakup models. These parameters were then used to solve a linearly implicit system of ordinary differential equations governing the evaporation process. Initially, a single injection event was simulated as a baseline, followed by simulations of dual injection strategies. Comparative analysis was conducted on the impact of fuel split ratios, with one set of cases maintaining fixed start of injection (SOI) crank angles and another set maintaining fixed end of injection (EOI) timings.