A comprehensive investigation of RANS and LES turbulence models for diesel spray modeling via experimental diesel schlieren imaging

Spray simulation is the basis of many engine simulations and directly impacts the quality of other simulations. Various models have been proposed to simulate spraying and the breakup and evaporation of fuel particles. The Kelvin-Helmholtz/Rayleigh-Taylor (KH-RT) model is one of the most common of these models. In this study, while analyzing the sensitivity of the KH-RT model constants on spray simulation, the effect of the LES and RANS turbulence model on spray penetration length and shape of the diesel spray contour is investigated. This study shows that both LES and RANS turbulence models along with the KH-RT model predict the spray penetration length with appropriate accuracy. While the RANS model, due to its averaging nature, does not accurately simulate the shape of the spray contour, which has very soft edges. Finally, the best method for simulating diesel spray and the proposed constants of the KH-RT model is presented.

Automated summary

Spray simulation is crucial for engine simulations, and the Kelvin-Helmholtz/Rayleigh-Taylor (KH-RT) model is commonly used. This study investigates the effects of KH-RT model constants, LES, and RANS turbulence models on spray penetration length and shape of diesel spray contour. The results show that both LES and RANS turbulence models, along with the KH-RT model, accurately predict the spray penetration length. However, the RANS model fails to accurately capture the soft edges of the spray contour.