Sökning: "Diesel spray auto-ignition"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Diesel spray auto-ignition.

1. 1. 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

3. 2. Development of Transient Flamelet Library Based Combustion Models

   Författare :Harry Lehtiniemi; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; auto-ignition; conditional moment closure; Tabulated chemistry; flamelet; spray; non-premixed combustion; Fysicumarkivet A:2012:Lehtiniemi;

   Sammanfattning : Three different methods for Reynolds-averaged Navier-Stokes computational fluid dynamics modeling of non-premixed ignition and combustion using tabulated chemistry have been developed. All methods make use of flamelet libraries, where the flamelet auto-ignition process is parameterized using a progress variable. LÄS MER

4. 3. 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

5. 4. Development and application of laser diagnostics - from laboratory devices towards practical combustion engines

   Författare :Zhenkan Wang; Förbränningsfysik; []
   Nyckelord :Combustion diagnostics; Laser induced fluorescence LIF ; Ultra-high-speed; Burst-mode laser; Ballistic imaging; Particle imaging velocimetry; Laser Doppler anemometry; Turbulent premixed combustion; Plasma; Internal combustion engine; Partially premixed combustion PPC ; Auto-ignition; OH radical; CH2O formaldehyde ; Fysicumarkivet A:2018:Wang;

   Sammanfattning : For many decades, research work on combustion has been focused on improving combustion efficiency and reducing harmful emissions. Laser diagnostics is one of the best ways to investigate the combustion process and emission formation as it is non-intrusive and it has high spatiotemporal resolution. LÄS MER

7. 5. Bio-diesel Spray Combustion Modeling Based on a Detailed Chemistry Approach

   Författare :Junfeng Yang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; engine modeling; bio-diesel; thermo-physical properties; detailed chemistry combustion; emissions formation; spray characteristics;

   Sammanfattning : The increased use of bio-diesel fuel is expected to reduce emissions of carbon-containing greenhouse gases. To optimize the application of bio-diesel in internal combustion engines, a theoretical model has been developed. LÄS MER