Interaction Effects During Combustion of Linear Arrays of Gaseous Fuel Pockets

Abstract

The numerical solution for the combustion of an infinite linear array of dense fuel gas pockets in a quiescent ambient is discussed in the present work. Fuel mass, flame, and gas pocket shape behaviors are analyzed in order to quantify the interference effects. The combustion process is considered isobaric. The model is based on mass, momentum, energy, and species conservation equations and considers the simple chemical reaction mechanism and ideal gas behavior. Coupling potentials are used in the solution of the energy and species conservations equations. The thermophysical properties, except the density, are assumed constant. The finite-volume method is used for the numerical solution, using a generalized system of coordinates and a nonstaggered grid. The SIMPLEC algorithm is applied to solve the modified pressure-velocity coupling. The flame and gas pocket morphological evolutions as well as the transient fuel consumption and the flame position behaviors are presented. The effects of the initial fuel and oxidant temperatures, of the interpocket distance, of the stoichiometric condition, of the heat of reaction, and of the mixture thermophysical properties on the combustion process are considered. Results show that the interactive effects on gas pocket linear array combustion are relevant only for small interpocket distances. Results also show flame shape temporal evolutions that indicate an oscillatory behavior dependent on the gas pocket burning conditions.

The authors acknowledge the financial support from CNPq, CAPES, and FAPERJ—Brazilian agencies for the funding of science—and the Brazilian Army.