Large eddy simulation for turbulent non-premixed fuel-rich combustion in a cylindrical combustor

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Combination of DOM with LES in a gas turbine combustor

A three-dimensional numerical study is conducted to investigate the radiative heat transfer in a model gas turbine combustor. The Discrete Ordinates Method (DOM/Sn) has been implemented to solve the filtered Radiative Transfer Equation (RTE) for the radiation modelling and this has been combined with a Large Eddy Simulation (LES) of the flow, temperature and composition fields within the combustion chamber. The radiation considered in the present work is due only to the hot combustion gases notably carbon dioxide (CO2) and water vapour (H2O), which is also known as the ‘non-luminous’ radiation. A benchmark problem of the ideal furnace is considered first to examine the accuracy and computational efficiency of the DOM in the three-dimensional general body fitted co-ordinate systems

Assessing the Effect of Differential Diffusion for Stratified Lean Premixed Turbulent Flames with the Use of LES-PDF Framework

Lean premixed stratified combustion is rapidly growing in importance for modern engine designs. This paper presents large eddy simulations for a new burner design to assess the predictive capability of the probability density function (pdf) approach to flames that propagate through non-homogeneous mixtures in terms of equivalence ratio. Although various efforts have been made in the past for the simulation of the same test case the novelty of this work lies to the fact that it is the first simulation effort that differential diffusion is accounted for given the relatively low Reynolds numbers (13,800) of the configuration. First mean and root mean square velocity simulations are performed for the isothermal cases to assess the effect of the grid resolution and the overall LES flow field solver. Then instantaneous snapshots of the flame are presented to provide insight to the structure of the flame and the effect of stratification. Finally, results for velocities, temperature and mixture fraction are presented and compared with the experimental data. Overall, the results are in very good agreement with experiments

High-Excitation Hole States in the (p,d) Reaction

This work was supported by National Science Foundation Grant PHY 76-84033 and Indiana Universit

Deep Hole States in the Mirror Nuclei 23-Mg and 23-Na

This work was supported by National Science Foundation Grant PHY 76-84033 and Indiana Universit

High Excitation Hole States in the (p,d) Reaction

This work was supported by National Science Foundation Grant PHY 75-00289 and Indiana Universit

Study of Stretched Configuration High-Spin States in the Nickel Region with the (d,α) Reaction

This work was supported by the National Science Foundation Grant NSF PHY 78-22774 A02 & A03 and by Indiana Universit

High-Excitation Hole States in the 24-Mg(p,d) Reaction

This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

Low-Lying Neutron-Hole Transitions in the 207-Pb(p,p') Reaction at 135 MeV

This work was supported by National Science Foundation Grant PHY 75-00289 and Indiana Universit

Large eddy simulation of a turbulent non-premixed propane-air reacting flame in a cylindrical combustor

Large Eddy Simulation (LES) is applied to investigate the turbulent non-premixed combustion flow, including species concentrations and temperature, in a cylindrical combustor. Gaseous propane (C3H8) is injected through a circular nozzle which is attached at the centre of the combustor inlet. Preheated air with a temperature of 773 K is supplied through the annulus surrounding of this fuel nozzle. In LES a spatial filtering is applied to the governing equations to separate the flow field into large-scale and small-scale eddies. The large-scale eddies which carry most of the turbulent energy are resolved explicitly, while the unresolved small-scale eddies are modelled using the Smagorinsky model with Cs = 0.1 as well as dynamically calibrated Cs. The filtered values of the species mass fraction, temperature and density, which are the functions of the mixture fraction (conserved scalar), are determined by integration over a beta probability density function (β-PDF). The computational results are compared with those of the experimental investigation conducted by Nishida and Mukohara. According to this experiment, the overall equivalence ratio of 0.6, which is calculated from the ratio of the air flow rate supplied to the combustion chamber to that of the stoichiometric reaction, is kept constant so that the turbulent combustion at the fuel nozzle exit starts under the fuel-rich conditions