wb4408B

Coursecode: wb4408B Coursename: Diesel engines B ECTS creditpoints: 4
Faculty of Mechanical Engineering and Marine Technology
Lecturer(s): Stapersma, prof. D., MSc., FIMarE.	Tel.: +31 15 27 83051
Catalog data: fuels, fuel treatment, fuel properties, ignition, combustion mechanisms, measurement of combustion heat release, heat transfer, gas velocities in cylinder, emissions, air pollution	Course year: MSc 1st year Language: English on request Semester: 2A / 2B Hours p/w: 2 Other hours: - Assessment: oral Assessm.period(s): 2B, Aug. (see academic calendar)
Prerequisites: wb1224, wb1220
Follow up: -
Detailed description of topics: Fuels - refining process, chemical structure of hydrocarbons - types and designation, availability - properties: composition (C/H ratio, S-content), density, viscosity, combustion value, ignition performance (CCAI) - (pre)treatment and separation Combustion - chemics and physics: atomizing, ignition (conditions, delay), explosion diagram, flame shape, thermal theory (Arrhenius), reaction mechanisms, chain reactions, premixed and diffusive combustion - heat release: mathematical model (Wiebe) and simulation of a cylinder process, practical measurement (incl. assessment of Top Dead Centre) - maximum pressure and temperature as a result of heat release Heat transfer between gas and wall: summation over time and location - heat transfer mechanisms: heat convection, heat conduction, gas radiation and flame radiation; order of magnitude of the different contributions - heat transfer coefficients: empirical methods (Nusselt, Eichelberg), methods based on dimension analysis (Annand, Woschni) - gas velocities in the cylinder: swirl, squish - heat transfer - theory of instationary heat transfer in the cylinder wall: stepchange and sinusoidal input. Emissions: A: Problem definition - types of emission: gaseous (CO2, CO HC, SOX, NOX) and particles (PM) - undesirable effects on health and environment - mechanisms of formation of emissions, particularly NOX B: Requirements - units and methods of conversion - legislation: stationary installations, road traffic, shipping C: Methods of reduction - choice of fuel - primary methods (engine optimalisation): injection (timing/pressure/rate/shape), air humidity, air inlet temperature, compression ratio, air excess ratio, variable turbine geometry (VTG) - more drastic primary methods (engine modifications): fuel/water emulsion, water injection, exhaust gas recirculation (EGR) - secundary methods: selective cathalytic reduction (SCR)
Course material: D. Stapersma, "Diesel engines IV: Fuels, Combustion and Emissions". D. Stapersma, "Diesel engines V: Heat Transfer". Diesel engines annex: Thermodynamical & chemical principles.
References from literature: paper "Impact of emission legislation on large engine design and operation" H. Niven (Ricardo)
Remarks (specific information about assessment, entry requirements, etc.):
Goals: Awareness of the global problem of fossil fuels availability and the undesirable effects of combustion for the environment i.e. pollutant emissions into the air. Acquiring a fundamental understanding of the chemical and physical aspects of combustion in a diesel engine Insight into theoretical and practical sides of heat transfer in the diesel engine. Basic knowledge of the emission problem, i.e.: types of emissions, legislation and methods of reducing emissions of diesel engines.
Computer use: Indirect; examples are given of the complex data processing by computer when measuring heat release and emissions.
Laboratory project(s):
Design content: Limited; assessment of the design parameters for the combustion process and the heat loss in the diesel engine.
Percentage of design: 25%