In modern diesel enginesandliquid rockets,fuel is injected into an environment of high pressure and high temperature. Theseenvironmentalconditions are often above the critical pressure and temperature of the injected fuel, whereas the fuel is in a subcriticalcompressedliquid state prior to injection, making it a transcritical injection. Moreover, the mixture of fuel andenvironmentalgas may have a higher critical point than the respective pure substance,resulting in a subcritical mixtureand phase separation effects due to multicomponent mixing. Complex thermodynamic models are required to represent and capture these physical phenomena.
In this research project, we numerically investigate turbulent mixing and two-phase phenomena in liquid fuel injection. For this purpose, we use an extended version of the flow solver OpenFOAM, containing a thermodynamic model that accounts for real gas thermodynamics and phase transition effects.
The figure shows a transcritical injection with phase separation due to multicomponent mixing. The two-phase region in the mixing zone is visualized by the rainbow color map.