Numerical Analysis of Unsteady Droplet Gasification Mechanism in Hot Environment

Canonical fluid dynamic analysis is applied to account for the contributing physical mechanisms and the order of magnitude of the transient moving droplet gasification rate based on energy and species conservation equation as eigenvalues in the general aerothermochemical environment. The results show surprisingly well coordinated self-organized thermofluidchemical mechanisms of dynamic evolution, sequenced by preheating of exterior gaseous mixture and interior liquid, gasification, ignition, combustion, and stages of transient developments of flame structure. Principal mechanisms and exterior interior binding reveal that there are gasification contribution partition changes caused by the convective and conductive transport processes, thermal accumulation and time-dependent variation of Spalding-Godsave (S-G) potential accompanied by the dynamic evolution. We found that both the exterior/interior convection and transient heating in the early phase play key roles in preheating period. This is followed by the gaseous phase ignition, exothermic chemical reaction and transient flame configuration, which control the gasification rate. In the full transient period, the external flow field’s contribution starts at approximately 86 % of the intrinsic gasification contribution to 100%, whereas the interior flow commences with -10% of intrinsic field gasification rate, but vanishes to nearly zero, respectively, when the quasi-steady state is reached.