A Comparison of Cold Sprays of DIPA (Diesel-IsoPropyl Alcohol blended fuel) and Pure Diesel Using Numerical Simulation

In the present work, numerical simulations of the pure diesel and diesel-isopropyl alcohol cold sprays are performed using OpenFoam software. These sprays are formed through injecting liquid fuel into an initially quiescent air in a constant volume high pressure chamber. The hybrid, Eulerian-Lagrangian formulation, along with a compressible version of k-ε model, is used. The numerical simulation consists of various sub- models for atomization, droplets breakup, drag and gravitational forces. The ability of the OpenFOAM software to predict spray tip penetration is validated against four cases by comparing the predictions against the available experimental data. In order to complete the input data for the simulations, physical properties of DIPA and Diesel (needed for cold spray simulation) are measured experimentally. Simulations are done in two chamber pressures (10 bar and 50 bar). Spray tip penetration, SMD, droplet size distribution and spray structure for DIPA and Diesel are presented and compared. The results show that the SMD of DIPA20 is smaller than that of pure Diesel. They also indicate that the spray tip penetrations for the two fuels are nearly the same regardless of the properties of the two fuels. It is concluded that DIPA20 could be used in traditional Diesel injection systems without any modifications to the engine geometry.