Fully integrated design exploration for in-cylinder simulation

We present a comprehensive efficient CFD based approach to virtually optimize the performance of a GDI combustion system from within a single simulation environment. In a first step the geometric designs space of the parametrized intake-port is explored to find better port designs. Studying 100 ports in a transient cold-flow simulation, improved designs can be identified best ones even doubling turbulent kinetic energy at ignition timing at only one percent penalty on trapped mass. In the second stage of the process the timings of a multi-pulse injection strategy are varied to further improve the turbulence level and fuel distribution homogeneity, thereby ensuring an ignitable mixture, minimum liquid fuel residual and fuel backflow into the intake by corresponding constraints. Studying 80 strategies allows the identification of better ones that improve TKE and fuel uniformity performance yet meeting the feasibility criteria in a highly constrained design space. A detailed correlation analysis of transient tumble, TKE and uniformity traces for some key injection strategies allows for a thorough understanding of the underlying physical mechanisms that lead to improved engine performance.