Abo Bibliothek: Guest
ICHMT DL Home Aktuelles Jahr Archive Vorstand International Centre for Heat and Mass Transfer

DIRECT NUMERICAL SIMULATION OF IGNITION AND PROPAGATION OF TURBULENT H2/AIR, CH4/AIR AND N-HEPTANE/AIR PREMIXED FLAMES

DOI: 10.1615/ICHMT.2008.CHT.1820
11 pages

Makoto Sato
Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8850, Japan

Shingo Matsuura
Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan

Mamoru Tanahashi
Department of Mechanical and Aerospace Engineering Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan

Toshio Miyauchi
Dept. Mechanical and Aerospace Eng., Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan; Organization for the Strategic Coordination of Research and Intellectual Properties Meiji University 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, Japan

Abstrakt

Direct numerical simulations (DNS) of ignition and propagation of turbulent premixed flames in homogeneous isotropic turbulence have been conducted for hydrogen/air, methane/air and n-heptane/air mixture to investigate effects of turbulence on ignition and propagation process. A detailed kinetic mechanism which includes 12 reactive species and 27 elementary reactions is used for hydrogen/air mixture and that includes 49 reactive species and 279 elementary reactions is used for methane/air mixture and a reduced kinetic mechanism which includes 38 reactive species and 61 elementary reactions is used for n-heptane/air mixture. In the ignition process, the high temperature region is stretched and its evolution is disturbed by surrounding eddies. This impediment leads to a significant ignition delay compared with the laminar case. Even if turbulent field is statistically same, the ignition delay significantly depends on local characteristics of turbulence. Ignition delay tends to increase with the increase of mean strain rate in the initial high temperature region. If the high temperature region is separated by the strong eddies in the initial process, the ignition of the mixture delays further. In the propagation process, the flame front is stretched and disturbed its evolution by strong eddies, and the flame propagates along the edge of eddies. The flame fronts that are enclosed by the burnt gas shows high heat release rate. This structure and increasing of flame front area enhance turbulent burning velocity. The flame propagation behaviours are different for fuel. Especially, strong stretching by eddy induces local extinction for methane cases, and the production of NO2 is enhanced in these regions. Pressure effects are also investigated for methane/air mixture.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH