Piloted ignition of solid fuels in turbulent back-step flows

摘要

Piloted ignition of solid fuels in dump combustor geometry subject to an igniter hot jet plume is numerically investigated. The objective of this work is to gain insight into the fuel ignition and subsequent flame spreading in this turbulent flow configuration. Conjugate heat transfer between gas and solid phases is considered to study the solid fuel heating and evaporation process; Solid phase energy equation is simultaneously solved coupled with flow governing equations. Finite rate one step second order chemistry is used in simulations. The gas phase equations along with the Spalart-Allmaras turbulence model are solved with a finite volume approach in which the AUSM~+ scheme is used to calculate the convective fluxes. The overall ignition delay time and flame spreading rate are predicted under a typical igniter operation. The results show that choosing a stronger igniter for reducing the ignition delay time does not necessarily guaranty the perfect firing process.