Sökning: "spray formation"

Visar resultat 16 - 20 av 107 avhandlingar innehållade orden spray formation.

1. 16. Optical Diagnostics of Soot in Combusting Sprays

   Författare :Raul Lima Ochoterena; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Optical diagnostics.; Laser Induced Incandescence LII ; Elastic Light Scattering ELS ; Soot formation; Flame temperature; Spray combustion; Light Extinction LE ;

   Sammanfattning : Optical diagnostics in combusting diesel sprays were carried out in the Chalmers High Pressure, High Temperature (HP/HT) spray rig at conditions similar to those in an internal combustion engine, reaching up to 100 bar and 630 ◦ C. Spray development studies and combustion characterisation were done by high speed shadowgraphs that were digitally processed to measure the start of combustion, break-up, droplets and vapour penetration. LÄS MER

3. 17. Modeling Auto-Ignition, Flame Propagation and Combustion in Non-Stationary Turbulent Sprays

   Författare :Anders Karlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; auto-ignition; transient; flame propagation; turbulence; spray formation; prediction; stirred reactor approximation; model; reduced chemistry; combustion;

   Sammanfattning : This thesis focuses on detailed numerical studies of spray formation, auto-ignition, envelope flame development and combustion in a simple two-dimensional axi-symmetric geometry. A Lagrangian -- Eulerian formulation is used to analyze the droplet motion and gas flow field. LÄS MER

4. 18. Studies on Diesel sprays under non-reacting and reacting conditions

   Författare :Chengjun Du; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diffusion flame; OH radical; ethanol; spray vaporization; soot formation; cavitation; turbulent; OH* chemiluminescence; laser extinction; LAS; Diesel sprays;

   Sammanfattning : Methods for reducing engine-out emissions are urgently needed to mitigate climate change and air pollution. In diesel engines, the quality of fuel-air mixing and the subsequent combustion process strongly affect fuel efficiency and engine-out emissions. LÄS MER

5. 19. Laser-based diagnostics for investigating soot formation in combustion processes

   Författare :MANU Mannazhi; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soot formation; Laser diagnostics; Combustion; Laser-induced Incandescence; Fysicumarkivet A2022:Mannazhi;

   Sammanfattning : In this work, laser-based diagnostic techniques were developed and applied to investigate soot formation in small-scale laboratory burners as well as in practical combustion devices. Quantitative 2D laser-induced incandescence (LII) measurements often use a cylindrical lens to shape the beam and illuminate the planar region of interest. LÄS MER

7. 20. Biodiesel Spray Combustion Modeling Based on a Detailed Chemistry Approach

   Författare :Junfeng Yang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduction and Validation; Spray Characteristics; Detailed Chemistry; Biodiesel;

   Sammanfattning : Replacing conventional diesel fuels with biodiesel has the potential to drastically reduce engine-out emissions of soot, carbon monoxide, and total unburnt hydrocarbons, at the cost of slightly increased nitrogen oxide emissions. However, to realize the full benefits of using biofuels in this way, there is a need for theoretical models describing their combustion in internal combustion engines. LÄS MER