Numerical Simulation of Hot Surface Ignition and Combustion of Fuel Sprays PDF Download

Author: Danyal Mohaddes Khorassani
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Due to their high energy density and ease of transportation, liquid fuels continue to be used in a variety of combustion systems, including in aerospace, automotive and industrial applications. Analysis of the underlying physics of multiphase combustion phenomena, particularly as it pertains to ignition, contributes to improved physical understanding and supports greater system reliability and safety. High-fidelity numerical simulations are particularly effective in supporting improved fundamental understanding, but detailed simulations of practical multiphase combustion configurations are highly computationally costly. The study of accidental ignition of liquid fuels and the development of computationally efficient means of performing physically accurate multiphase combustion simulations are therefore important avenues of scientific inquiry. This dissertation considers the problem of the ignition and combustion of a wall-impinging fuel spray using four complementary approaches. First, to analyze the long-term wall heat flux caused by a wall-stagnating spray flame, a steady, one-dimensional, multi-continuum formulation is developed with consideration given to conjugate heat transfer effects. Second, an unsteady, one-dimensional, multi-continuum formulation is developed and a broad parametric study of the hot surface ignition of wall-stagnating fuel sprays is conducted. Third, high-fidelity three-dimensional large-eddy simulations are performed in an Eulerian-Lagrangian formulation using a finite-rate chemistry model. Fourth, the substantial computational cost of the high-fidelity simulations performed motivates the development of a computationally efficient spray combustion modeling framework. This dissertation extends the Pareto-efficient combustion (PEC) modeling framework to spray combustion through a rigorous analysis of the governing equations. The spray-augmented PEC formulation is applied to the high-fidelity simulation of a wall-stagnating spray flame and to the simulation of a realistic gas turbine combustor to demonstrate improved physical fidelity compared to tabulated chemistry, while reducing computational cost compared to monolithic finite-rate chemistry.