<p>Spray combustion processes are widely utilized in various engineering applications, including energy sources for propulsion and transportation systems, electric power generation in, waste disposal, and energy recovery and furnaces to process materials for use. The combustion of liquid fuels that are atomized into the combustion chamber in the form of a spray satisfies a significant proportion of the total energy demand. Spray combustion is utilized in diverse engines such as liquid rocket fuel engines, diesel engines, gas turbine combustion chambers, hybrid rocket engines, and ramjets in the domains of propulsion and transportation. From an intricacy standpoint, spray combustion can be considered as one of the most complex engineering topics. Therefore, the numerical analysis of combustion processes has a pivotal role in increasing the efficiency and effectiveness of combustion systems and reducing pollutants. The present study investigates the combustion of diesel fuel spray, one of the most widely used fuels, numerically in the presence of an electric field using Open FOAM software. Additionally, the study scrutinizes the impact of enhancing the electric charge of the fuel, increasing the voltage, and reducing the distance between the electrodes on the combustion process. The outcomes of spray combustion in the presence of an electric field are compared with the experimental data procured in Sandia’s laboratory, indicating the enhancement of combustion efficiency, as well as the reduction of pollutants such as carbon monoxide and nitrogen oxides. This suggests the affirmative influence of the electric field on the combustion process of diesel fuel spray. In addition, this study introduces a systematic evaluation of the electric-field influence on reacting diesel spray by simultaneously examining three key parameters: the level of electric charge carried by the fuel, the applied voltage, and the distance between electrodes. This multi-parameter approach has not been previously addressed in the literature. The numerical model is validated against Sandia ECN experimental data, demonstrating good agreement for vapor penetration, flame lift-off length, and ignition delay. Results show that electric-field-induced modification of droplet motion enhances fuel–air mixing, increases combustion completeness, and reduces carbon monoxide emissions, while the resulting changes in temperature distribution influence NOx formation. These findings highlight the potential of electric-field-assisted spray control as an effective strategy for improving combustion performance and emission characteristics in diesel-based systems.</p>