THEORETICAL INVESTIGATION OF TURBULENT COMBUSTION IN STRATIFIED INHOMOGENOUS MIXTURES USING DIRECT NUMERICAL SIMULATION

Completed

Fossil Fuels: Oil Gas and Coal(Oil and Gas, Oil and gas combustion)

Basic and strategic applied research

ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Professor N Chakraborty
Mechanical and Systems Engineering
Newcastle University

Standard

EPSRC

01 August 2007

31 July 2010

36 months

£147,093

Mechanical engineering

North East

Engineering science: flow -- Materials, Mechanical and Medical Eng

Professor N Chakraborty, Mechanical and Systems Engineering, Newcastle University

The aim of this project is to understand the effects of turbulence on hydrocarbon fuel combustion where the fuel and oxidizer distribution form a highly stratified mixture at the time of ignition. For stratified charge combustion the reactants are neither homogeneously mixed (premixed) nor completely separated (non- premixed). Thus the analysis of this kind of combustion has special modelling needs in comparison to fully premixed or fully non-premixed flames. Turbulent combustion in a stratified fuel-air mixture is highly relevant in the context of both spark-ignition gasoline and compression-ignition Diesel engines and has the potential for reducing fuel consumption especially at low-speed, light- load operations in automobile applications. Stratified-charge combustion can also be found in the Lean Premixed Prevaporised (LPP) combustors in aircraft gas turbines where fuel and injected secondary air form an inhomogeneous fuel-air mixture ahead of the flame front. The capability ofpredicting accurately the flame propagation behaviour in the presence of mixture inhomogeneities and intense turbulence would facilitate the development of low-emission, energy-efficient devices, such as automotive engines and gas-turbine combustors. The proposed research project consists of three parts. In the first, three-dimensional (3-D) Direct Numerical Simulations (DNS) with simplified chemistry, appropriate for the combustion of realistic hydrocarbon fuels, will be performed for a variety of mixing fields and turbulence intensities to enhance the present state of fundamental understanding and to create a database for the assessment of existing combustion models and to develop new models wherever necessary. Three-dimensional DNS with a reasonable degree of detailed chemistry will be carried out based on the information gained from 3-D DNS with simplified chemistry. The second part of the project involves the development of a combustion model in the context of Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulations (LES). The model will be implemented with a view to future incorporation into industry-standard Computational Fluid Dynamics (CFD) packages, which can then be used for engineering design purposes

01/01/07