This thesis aims to make a comprehensive analysis of high-pressure fuel injection and turbulent mixing phenomena under sub-, trans-, and supercritical conditions. The events such as transcritical flows exist in a wide range of engineering applications, like as rocket engines, gas turbines, and internal engine combustion with particular emphasis on modern Diesel engines. The analysis is based on computational simulations conducted with CFD code. Before performing the simulations, the first step was the implementation of a real-gas thermodynamic framework based on a cubic equation of state in CFD package and adjustment of Eulerian single-phase solver for conditions typical like in Diesel engines. Transport phenomena in IC engines are sufficiently complex, and it is challenging to describe these phenomena only with experimental measurements, mainly because there are not existing sufficiently enough quantitative results. Therefore, validation of the capabilities of the real-gas model was first performed for the DLR cryogenic injection case. On the other hand, the ECN Case Spray A with high-pressure fuel injection is at typical operating conditions of Diesel engines. Detailed pieces of information on this experiment are available, which supports a CFD simulation with real fluid thermodynamics. Additionally, to Spray A case, for validation of the real-gas model has been used LTT Erlangen n-decane case, which also has conditions typical like in Diesel engine. The results obtained from CFD simulations are compatible with those obtained from experimental measurements and thus confirmed the possibility of applying implemented a numerical framework for describing flow phenomena under sub-, trans- and supercritical conditions or conditions typical like in modern Diesel engines.weiterlesen