End-to-end modeling of fuel injection via static coupling of internal flow and ensuing spray

Abstract Accurate knowledge of fuel spray behavior is of utmost importance for liquid-fuel-based combustion systems. Fuel properties, injector geometry, operating conditions, and thermal state of the combustion chamber determine the fuel’s ability to mix and burn efficiently. Three-dimensional computational-fluid-dynamics models can reveal the complex dynamics of the injector’s internal flow, as well as the spray breakup, evaporation, mixing, and combustion. However, time and length scales of in-nozzle flow and ensuing spray can differ by several orders of magnitude, limiting the feasibility of a simultaneous solution of the entire chain of physics. This work explores an end-to-end approach to decouple the problem at the injector outlet via a static-coupling framework. Flowfields are sampled at the injector exit, stored into spatiotemporally resolved maps, and used to initialize a Lagrangian spray whose properties reflect the flow’s instantaneous state as predicted by the in-nozzle flow simulations. Comparisons against typical rate-of-injection results and qualitative validation against optical spray data highlighted the ability of static coupling to unveil spray physics that would otherwise be missed.