Vaporization and combustion of an electrospray of heptane in a small chamber

Abstract

An Eulerian/Lagrangian model is used to describe the vaporization and combustion of a spray of electrically charged droplets of heptane that is injected in a small chamber together with a coflow of preheated air. The effects of the inlet air temperature, the fuel flow rate and the overall equivalence ratio are investigated for globally lean systems. Combustion may occur in a lifted lean premixed flame after the fuel has fully vaporized and mixed with the air coflow, or it may begin before the fuel diffuses in the air coflow, in a layer of intense reaction that locally depletes the oxygen and leaves behind a region of hot fuel surrounded by a diffusion flame. Transition between these two modes is discussed, and ignition and extinction conditions are determined.