Seminarvortrag: Prof. Herrmann, Arizona State University
Using Simulations to Predict Atomization
Prof. Marcus Herrmann
School for Engineering of Matter, Transport and Energy, Arizona State University, USA
09.Juli 2019, 16:30-17:30
Significant progress has been made in the past decade to predict atomization using detailed numerical simulations. Much of the early work in this area focused on atomization in simple geometries, for example liquid jets issuing from straight pipes into rectangular channels with and without crossflows. However, in the past couple of years, simulations of realistic complex injectors have become viable, offering a path to study application relevant geometries not only via experiments, but also via detailed simulations. In this seminar, approaches will be discussed to enable the predictive simulation of atomization in complex geometries including hybrid approaches to tackle the vast range of scales present in atomization processes, ranging from centimeter scales of the injector down to the sub-micron scale of the smallest drops. Simulation results for a realistic high-shear gas turbine injector consisting of multiple liquid jets injecting into a swirling crossflow will be presented and compared to available experimental data for the configuration. The results highlight the current capabilities to predict atomization in realistic configurations using detailed simulations, but also show the need for continued improvement of the numerical techniques to simulate atomization including a switch to Large Eddy Simulation (LES) approaches to make the techniques viable for industrial applications. A dual scale modeling approach will then be discussed to tackle atomization simulations in an LES framework. Here, the dual nature of surface tension on small scales may necessitate novel modeling approaches that go beyond the classical cascade hypothesis underlying traditional LES approaches.