Sökning: "flame development"

Visar resultat 1 - 5 av 141 avhandlingar innehållade orden flame development.

1. 1. 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

3. 2. Neonatal Developmental Neurotoxicity of Brominated Flame Retardants, the Polybrominated Diphenyl Ethers (PBDEs)

   Författare :Henrik Viberg; Per Eriksson; Susan Schantz; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; brominated flame retardants; polybrominated diphenyl ethers; PBDE; neonatal; development; neurotoxicity; behaviour; cholinergic system; Biologi; Biology; Biologi;

   Sammanfattning : This thesis examines developmental neurotoxic effects of polybrominated diphenyl ethers (PBDEs), PBDE 99, PBDE 153, and the fully brominated PBDE 209, after exposure during the newborn period in rodents. Our environment contains vast numbers of contaminants, including the flame retardants, PBDEs. LÄS MER

4. 3. Flame Dynamics and Deflagration-to-Detonation Transition

   Författare :Damir Valiev; Börje Johansson; R. J. M. (Rob) Bastiaans; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; flame; premixed; instability; fractal; deflagration; detonation; DDT; simulation; Physics; Fysik;

   Sammanfattning : Various premixed flame phenomena are studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics is essential for all premixed combustion problems where multidimensional effects cannot be disregarded.The present thesis consists of six parts. LÄS MER

5. 4. Theoretical and Experimental Investigations of Nonlinear Flame Instability

   Författare :Li-Zheng Ma; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; nonlinear hydrodynamic instability; flame propagation and stretch effects; shock induced flame instability; tulip flame formation; interface tracking; the Schlieren technique; level set approach;

   Sammanfattning : Flame instability is both important and difficult to understand. Mechanisms of instability are complex, because instability often involves an interaction between several different physical phenomena, such as an unsteady chemical reaction, unsteady flame propagation generating an unsteady flow, acoustic waves or shock waves. LÄS MER

7. 5. Development and Application of Non-linear Mid-infrared Laser Spectroscopy for Combustion Diagnostics

   Författare :Zhiwei Sun; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Degenerate four-wave mixing; Polarization spectroscopy; Mid-infrared; Non-linear laser spectroscopy; Laser diagnostics; Combustion; Flame; HITRAN; Concentration; Temperature; Fysicumarkivet A:2012:Sun;

   Sammanfattning : The work reported in this thesis involved the development and application of two novel infrared non-linear laser techniques, namely mid-infrared polarization spectroscopy (IRPS) and mid-infrared degenerate four-wave mixing (IR-DFWM) to combustion diagnostics. These two techniques meet the needs of species concentration detection in combustion environments, especially for those species lacking accessible electronic (one-photon) transitions in the ultraviolet (UV) or visible spectral region. LÄS MER