The fuel injection process in modern diesel engines is a complex two phase problem. The cause effect chain (Injection-Evaporation-Mixing-Combustion) is strongly coupled and needs a variety of models to capture the physical and chemical modes of action. For the numerical discretization method the finite volume method (FVM) is utilized. The so called Navier-Stokes-Equation is solved in order to solve the flow field. Additionally, equations for energy, chemical reactions and evaporation are solved. The gaseous phase is solved in eulerian coordinates and the liquid phase is described by lagrangian particles that interact with the gas phase. Each particle, a so-called parcel, represents a number of droplets that share the same properties (temperature, size, velocity). The coupling between parcels and gas phase involve momentum and evaporation source terms.

In spray combustion the mixture formation is an important quantity. The quality of the mixture field determines the accuracy of the combustion and pollutant formation simulation. Therefore, high fidelity Large Eddy Simulations (LES) are frequently used in literature. A large amount of the turbulent structures/eddies are resolved (high grid resolution), only a smaller amount of turbulence has to be modeled using appropriate turbulence models. The combustion model used in this project is the so-called flamelet model, which allows speeding up the simulation significantly. The idea behind the flamelet model is that a flame structure can be represented by a manifold of one dimensional flame structures, so-called flamelets. The great advantage of the flamelet model lies in the ability to precompute the flamelet solutions for all relevant thermochemical states and store them in look up tables. During the simulation the chemical source terms can be looked up, instead of solving expensive differential equations, using appropriate access variables.