Sökning: "engine simulations"

Visar resultat 1 - 5 av 211 avhandlingar innehållade orden engine simulations.

1. 1. Creation and destruction of in-cylinder flows : Large eddy simulations of the intake and the compression strokes

   Författare :Martin Söder; Laszlo Fuchs; Angelo Onorati; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirl; Tumble; Compression; Engine; LES; CFD; engine turbulence; engine simulations; intake flow structures; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The aim of this thesis is to increase engine efficiency by studying the flow structures created in an engine cylinder during the intake phase and the effect of the subsequent compression.The invention of the combustion engine has enabled three centuries of economic growth fueled by energy stored as hydrocarbons. LÄS MER

3. 2. Full Cycle Engine Simulations with Detailed Chemistry

   Författare :Adina Gogan; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plasmas; Gaser; Gases; fluid dynamics; aktuariematematik; programmering; operationsanalys; Statistik; actuarial mathematics; programming; operations research; Statistics; detailed kinetics; emissions; engine knock; autoignition; modeling; spark ignition engine; diesel engine; fluiddynamik; plasma; Technological sciences; Teknik; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik; Motors and propulsion systems; Motorer; framdrivningssystem; stochastic reactor model;

   Sammanfattning : The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines. A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from the residual gas has on the autoignition onset. LÄS MER

4. 3. Coupled Simulations of Cooling and Engine Systems for Unsteady Analysis of the Benefits of Thermal Engine Encapsulation

   Författare :Blago Minovski; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Oil system; Cooling system; Drive cycle; CFD simulations; Fuel consumption; Engine encapsulation; 1D simulations;

   Sammanfattning : A well-designed engine encapsulation can extend engine cool-down time significantly - on the order of 500 - 700%. This is expected to have a sensitive influence on the fuel consumption due to the increased probability for high oil temperatures at the following engine start, reduced length of the initial warm-up period and consequently, reduced friction losses. LÄS MER

5. 4. Engine Encapsulation for Increased Fuel Efficiency of Road Vehicles

   Författare :Blago Minovski; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; coupled simulations; powertain cooling systems; warm-up; 1D simulations; thermal engine encapsulation; cool-down; fuel consumption; numerical analysis; 3D CFD simulations;

   Sammanfattning : Thermal engine encapsulation is an increasingly popular design choice, which insulates the engine from the external environment and retains heat in the engine after it is turned off. This decelerates motor cool-down and increases the probability for high initial temperature at a subsequent engine start, resulting in shorter warm-up and reduced friction between engine parts. LÄS MER

7. 5. Stochastic Reactor Models for Engine Simulations

   Författare :Martin Tunér; Förbränningsmotorer; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SRM; Stochastic Reactor Model; Engine Simulation; Chemical kinetics; HCCI; Direct injection; Combustion; NVO; Modeling; PDF;

   Sammanfattning : The aim of the thesis work is the further development of practical engine simulation tools based on Stochastic Reactor Models, SRMs. Novel and efficient implementations were made of a variety of SRMs adapted to different engine types. The models in question are the HCCI-SRM, the TwoZone SI-SRM and the DI-SRM. LÄS MER