Multi-Hole Injector Optimization for Spark-Ignited Direct-Injection Gasoline Engines

Project Description

Auto companies must accelerate engine designs to meet government fuel economy regulations. The efficiency of in-cylinder combustion is highly sensitive to fuel air mixing and fuel injector design. Improvements can be achieved through the validation and development of high-fidelity, multi-processor computing codes exercised over a wide range of typical engine operating conditions.

The research in this ALCC project seeks to extensively validate available computational tools for gasoline sprays under a large matrix of test conditions and injector configurations. The outlined approach combines high-fidelity internal nozzle computations with advanced toolsets for computing full spray dynamics. Internal flow results are computed using OpenFOAM. External spray results are simulated using a Lagrangian droplet technique in CONVERGE. The information exchange between both codes is handled through a custom user-defined function. Both modeling codes are capable of running in parallel. This work is part of a larger plan to develop advanced toolset to accelerate engine design and improve vehicle fuel economy.

The modeling work is extensively validated against experimental spray images under a large matrix of test conditions spanning variations in ambient pressure and fuel temperature. The experiments also include conditions leading to flash-boiling injection; hence, the computational research performed has a broader impact on applications involving multiphase flows with sprays beyond the automotive applications.