Sökning: "STATIONARY FLAMES"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden STATIONARY FLAMES.

1. 1. Numerical Modeling of Soot and NOx Formation in Non-Stationary Diesel Flames with Complex Chemistry

   Författare :Feng Tao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; soot and NOx formation; non-stationary Diesel sprays; complex chemistry; Diesel spray auto-ignition; reaction zone structure; Diesel flame liftoff; turbulence-chemistry interaction;

   Sammanfattning : A complex chemistry model of reduced size (65 species and 268 reactions) derived on the basis of n-heptane auto-ignition kinetics, small hydrocarbon oxidation chemistry, polyaromatic hydrocarbon (PAH) and NOx formation kinetics together with a phenomenological soot model has been implemented in the KIVA code for multidimensional Diesel spray combustion simulations. An EDC (Eddy Dissipation Concept) based partially stirred reactor model is used to handle the turbulence-chemistry interaction. LÄS MER

3. 2. Dynamics of curved flames in compressible flows

   Författare :Oleg Travnikov; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; fysik; Physics;

   Sammanfattning : Influence of flow compressibility on propagation and stability of premixed laminar flames in gaseous combustible mixtures has been investigated. A linear analysis of the intrinsic hydrodynamical instability of a planar flame front has shown that the instability growth rate is very sensitive to the compressibility effects and can increase significantly even for rather small Mach numbers of the flame generated flow. LÄS MER

4. 3. Modelling effects of flame development on stationary and oscillating premixed turbulent combustion

   Författare :Pratap Sathiah; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame development; Keywords: Premixed turbulent flame; Flame Speed Closure model;

   Sammanfattning : The vast majority of contemporary models of premixed turbulent flames applied to multi-dimensional RANS numerical simulations of combustion in gas turbine engines and aero-engine afterburners focus on fully-developed flames, characterized by fully-developed turbulent diffusivity, thickness, and burning velocity. However, abundant experimental data obtained from statistically stationary premixed flames clearly show that a typical turbulent flame develops as it is convected by mean flow from a stabilization zone. LÄS MER

5. 4. Modelling of methane and hydrogen enriched methane flames in industrial gas turbine burners

   Författare :Daniel Moell; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The majority of the power production in the world today is based on combustion of coal, oil and natural gas. Most countries have agreed that the amount of CO2 emitted to the atmosphere will have to be decreased to keep the global warming at sustainable levels. LÄS MER

7. 5. The role of Landau-Darrieus instability in flame dynamics and deflagration-to-detonation transition

   Författare :Damir Valiev; Börje Johansson; Vladimir Karlin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame; premixed; instability; front; Landau; Darrieus; fractal; freely; deflagration; detonation; transition; DDT; modeling; simulation; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : The role of intrinsic hydrodynamic instability of the premixed flame (known as Landau-Darrieus instability) in various flame phenomena is studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics and effect of Landau-Darrieus instability is essential for all premixed combustion problems where multidimensional effects cannot be disregarded. LÄS MER