Gasoline direction injection (GDI) is a new technology implemented in engines to improve efficiency and performance of vehicles. Unlike the conventional port fuel injected (PFI) engine, in which gasoline is injected into the intake manifold of the engine, in GDI engines gasoline is injected directly into the combustion chamber. Recent measurements taken from vehicles equipped with PFI and GDI engines have indicated increased emissions of aerosol particles from GDI engines, especially in the immediate vicinity of the roadway. The evolution of these particles in the near-roadway environment is not well understood. In this project, computational fluid dynamics (CFD) simulations will be performed to predict formation, turbulent dispersion, and subsequent evolution of aerosol particles emitted by vehicles equipped with gasoline engines. Model predictions will be compared against available in-house experimental measurements. The objective of the current project is to understand the complex interplay between the properties of emissions at the vehicle tailpipe and their physiochemical evolution in the near-roadway environment through a number of systematically designed CFD simulations. The project requires a basic understanding of fluid mechanics and numerical methods.