Sökning: "Auto-ignition"

Visar resultat 11 - 15 av 38 avhandlingar innehållade ordet Auto-ignition.

1. 11. 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. 12. HCCI Combustion by Retaining Residuals. Development and Analyses of a Method to Reduce Fuel Consumption for Passenger Car Gasoline Engines

   Författare :Lucien Koopmans; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; gasoline; variable valve timing; homogeneous charge compression ignition HCCI ; internal combustion engines; fuel-consumption; engine emissions; controlled auto-ignition CAI ;

   Sammanfattning : The demand for more powerful engines on one hand, and greater fuel-efficiency on the other, requires a revolution in engine combustion technology. Homogeneous charge compression ignition (HCCI) can be a fuel-saving, low emissions approach that seems to be very suitable for large displacement passenger car engines. LÄS MER

4. 13. Large Eddy Simulation of Turbulent Flow and Combustion in HCCI Engines

   Författare :Rixin Yu; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent combustion; Numerical methods.; LES; Temperature inhomogeneity; HCCI combustion; In-cylinder flow;

   Sammanfattning : This thesis deals with numerical simulations of the turbulent combustion process in Homogeneous Charge Compression Ignition (HCCI) engines. An accurate and computationally efficient Large Eddy Simulation (LES) model was developed and used throughout this thesis to investigate the development of in-cylinder turbulence, temperature stratification, onset of auto-ignition, and development of the reaction fronts. LÄS MER

5. 14. Direct Numerical Simulations of Low Temperature Combustion in IC Engine Related Conditions

   Författare :Fan Zhang; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This thesis deals with direct numerical simulation (DNS) of low temperature combustion in internal combustion engine related conditions. In particular, HCCI (homogeneous charge compression ignition), SACI (spark assisted ho-mogeneous charge compression ignition) and PPC (partially premixed charge combustion) were investigated to gain deeper understanding on the details of the combustion process. LÄS MER

7. 15. Spark Assisted Compression Ignition, SACI

   Författare :Håkan Persson; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame propagation; PLIF; LDV; chemiluminescence imaging; residuals; negative valve overlap; low temperature combustion; SACI; spark assistance; HCCI; turbulence; charge stratification; cycle to cycle;

   Sammanfattning : The strong focus on decreasing carbon dioxide emissions due to limited natural resources of fossil fuel as well as alarming climate changes drives the research and development of our prime mover, the combustion engine, faster then ever. The minimum requirement is a power source with increased efficiency while emitting ultra low levels of hazardous local and regional emissions. LÄS MER