Student Posters Repository

In pressure atomizers a liquid is highly accelerated before it is discharged. The acceleration results in a local decrease of the static pressure even below vapor pressure which leads to partial evaporation (cavitation) of the fluid. Liquid-embedded vapor structures are subsequently advected into regions of higher pressure where they collapse and emit intense shock waves with post-shock pressures of more than 10,000 bar. These collapse events can cause severe damage of the injector which is called ‘cavitation induced erosion’. On the other hand, the collapse-induced turbulence can enhance the spray break up, which is a desired effect. In order to numerically investigate the effects of cavitation we employ a density based finite volume method that takes into account full compressibility of all phases to capture the shock wave after the collapses. For the numerical model an implicit large eddy approach is utilized, where the truncation error of the discretization scheme serves as a physically consistent subgrid-scale model for turbulence. Compressible Large Eddy Simulations of realistic geometries are challenging because of the required high spatial and temporal resolutions.