High-Fidelity Design Tools and Technologies for High-Pressure Heavy Fuel Injectors

The objective of the proposed SBIR project is to develop a computational tool capable of predicting the atomization of liquid injected through a practical I.C. Engine fuel injector under realistic operating conditions. The goal of the present study is to advance an existing state-of-the-art simulation methodology in several areas to substantially reduce the computational cost while still providing a predictive capability of the atomization process. To achieve this goal, a hybrid volume-of-fluid method (VoF) will be developed that enriches the interface reconstruction with Lagrangian marker particles to improve the ability to capture under-resolved interfacial structures. The breakup of under-resolved liquid structures will be modeled by theoretical instability theory to predict post-breakup droplet sizes. The resulting droplets are then represented in a Lagrangian particle/parcel description and undergo secondary atomization with evaporation. In this modeling approach, a significant reduction in computational cost will be achieved by relaxing the severe resolution requirements of thin ligaments and sheets/bags in high Weber number flows. During Phase I, efforts will be made to develop the subgrid breakup model based on the hybrid VoF method and to validate using the problem of turbulent atomization of liquid fuel with comparison to Direct Numerical Simulation data and experimental measurements.