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This paper describes a novel design and verification process for analytical methods used in the development of advanced combustion strategies in internal combustion engines (ICE). The objective was to improve brake thermal efficiency (BTE) as part of the US Department of Energy SuperTruck program. The tools and methods herein discussed consider spray formation and injection schedule along with piston bowl design to optimize combustion efficiency, air utilization, heat transfer, emission, and BTE. The methodology uses a suite of tools to optimize engine performance, including 1D engine simulation, high-fidelity CFD, and lab-scale fluid mechanic experiments. First, a wide range of engine operating conditions are analyzed using 1-D engine simulations in GT Power to thoroughly define a baseline for the chosen advanced engine concept; secondly, an optimization and down-select step is completed where further improvements in engine geometries and spray configurations are considered.

Advanced injection schedules involving multiple injections have been utilized for reducing the peak cylinder pressure, phasing heat release rate, and reducing emissions in diesel engines. The timing and duration of the injections determine the injection schedule efficacy at achieving these effects. The goal of this work is to develop tools to track multiple injections to develop a better understanding of interaction mechanisms between subsequent injections. Both timing and duration effects are captured by using three different dwell times and seven injection durations. Experimental gas jet studies are conducted using schlieren. The jet-tip penetration rate, S, results do not reveal significant differences in jet-tip penetration with variations in the first-injection duration and dwell between injections.