Avancerad sökning

Hittade 5 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Ageing behavior of plastics used in automotive fuel systems

   Författare :Xin-Feng Wei; Mikael S. Hedenqvist; Richard Olsson; Ulf W Gedde; Pieter Gijsman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automotive; Ageing; Polyamide; Diesel; Biodiesel; Diffusion; Oxidation; Plasticizer migration; Mechanical properties; Fracture behavior.; Fordon; Åldrande; Polyamid; Diesel; Biodiesel; Diffusion; Oxidation; Mjukgöraravgång; Mekaniska egenskaper; Brottegenskaper;

   Sammanfattning : The increase in service temperature and the use of biobased fuels, such as biodiesel, have raised concerns on the short/long-term performance of plastic components used in automotive fuel systems.In this work the ageing behavior of unreinforced and glass-fibre reinforced polyamide 12 (PA12), exposed to three different fuels (petroleum diesel, biodiesel, and a mixture of these (80/20)) at high temperature, was investigated. LÄS MER

3. 2. On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines

   Författare :Ola Stenlåås; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bränslen; sprängämnen; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; Internal Combustion Engine; Emission; SI; Spark Ignition; HCCI; Homogeneous Charge Compression Ignition; zone model; Chemical Kinetic; Engine simulation; Reformed Methanol; Hydrogen; Knock; Auto Ignition; NO; Piston Motion; Nitric Oxide; Premixed Charge;

   Sammanfattning : The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model. Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. LÄS MER

4. 3. Large Eddy Simulation of Turbulent Combustion in PPC and Diesel Engines

   Författare :Rickard Solsjö; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large eddy simulation LES ; turbulent spray combustion; Lagrangian particle tracking LPT ; diesel engines; partially premixed combustion PPC engines.;

   Sammanfattning : This thesis deals with large eddy simulations (LES) of turbulent combustion processes in direct injection internal combustion (IC) engines. Modeling of direct injection IC engine combustion involves modeling of turbulent spray/gas two-phase flow, modeling of chemical reactions of large hydrocarbon fuels and coupling of chemistry with turbulent flows. LÄS MER

5. 4. Physical Modeling and Control of Low Temperature Combustion in Engines

   Författare :Anders Widd; Institutionen för reglerteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The topic of this thesis is model-based control of two combustion engine concepts, Homogeneous Charge Compression Ignition (HCCI) and Partially Premixed Combustion (PPC), using physics-based models. The studied combustion concepts hold promise of reducing the emission levels and fuel consumption of internal combustion engines. LÄS MER

7. 5. Processes in Optical Diesel Engines - Emissions Formation and Heat Release

   Författare :Ulf Aronsson; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diesel Engines; Optical Engines; Heat Release; Combustion; Emissions Formation; Mechanical Deformation;

   Sammanfattning : This project deals with questions related to generic diesel combustion research and optically accessible engines are used to study the combustion process. Images of the combustion are analyzed together with in-cylinder pressure and exhaust gas emission measurements. LÄS MER