Experimental and Computational Study of n Heptane Autoignition in a Direct Injection Constant Volume Combustion Chamber

Abstract

The purpose of this study was to characterize experimental nheptane combustion behavior in a directinjection constantvolume combustion chamber (DICVCC), using chamber pressure to infer ignition delay and heatrelease rate. Measurements generally displayed expected trends and indicated entirely premixed combustion with no mixingcontrolled phase. A significant finding was the observation of negative temperature coefficient (NTC) behavior. Comparing results with CHEMKINPRO simulations, it was found that a homogeneous combustion model was reasonably accurate for ignition delays longer than 5 ms. The combination of NTC behavior and homogeneous fuelair mixtures suggests that this DICVCC can be useful for validation of chemicalkinetic mechanisms.