Flame-Ignition interaction in partially premixed mixtures
Current proposal is related to our recently granted project VR 2015-05206. By this application, I am seeking the computational resources required to carry on the project. Below, is a brief description of the the projects aims, tasks and outcomes. This project aims at studying a class of combustion where all modes of combustion can coexist and interact with each other by the mean of high fidelity Computational Fluid Dynamics (CFD) approach. We aim at gaining an improved understanding of the physics of the onset and extinction of ignition sites in partially premixed mixture; the conditions that ignition mode of combustion can transform to flame modes; the interaction between ignition waves and flames and its impact on the structure of reaction front; the role of low-temperature chemistry of fuel on ignition-flame interaction. The goals are: (1) to improve the understanding the mechanism of the onset and extinction of ignition sites in partially premixed mixtures, and the transition from ignition to flames; (2) to scrutinise the conditions in which the first ignition sites transform into a flame front; (3) to improve the understanding the interaction between ignition waves and flames; (4) to understand the role of low-temperature chemistry pathways of fuel on the stabilisation and dynamics of the ignition and flame fronts; (5) to generate high quality numerical database using direct numerical simulations and based on the database to explore and develop high accuracy and highly efficient mathematical model to describe and predict the interaction among the various modes of combustion in partially premixed mixture. This project is focusing on generic aspect of multi-mode combustion with strong industrial interest of advanced combustion development. We focus on the lifted jet flames in vitiated coflow configuration, which resembles the combustion process found in PPCI engines. We plan to explore the behavior of fuel from biomass gasification (syngas) and biofuels (alcohols and biodiesel). We employ high fidelity numerical approach, i.e., direct numerical simulation (DNS) and large eddy simulation (LES) and make use of the available experimental data in the literature. The project is well fitted to the Swedish National Policy on research and innovation for the sustainable energy system by providing fundamental knowledge on clean and efficient combustion techniques for various fuels including renewable fuels such as biomass derived fuels.