Course Outline Combustion MECH 6191 Department of Mechanical and Industrial Engineering Concordia University Instructor: Dr. Hoi Dick Ng Room: EV 004.229 Tel: (514) 848-2424 ext 3177 E-mail: hoing@encs.concordia.ca Office Hours: Mondays 1:30pm - 3:00pm or by appointment Webpage: http://users.encs.concordia.ca/~hoing/Teaching/mech6191/mech6191.html • Contain class lecture powerpoints & supplements • Homework exercises • Last minute announcements Motivation Combustion What is this course all about? What is combustion??? What is combustion? Combustion: the study of chemical reactions between fuel and oxidizer molecules resulting in the increase in the internal (thermal) energy of the products from the difference between the chemical bond energies of the reactant and product species CH4 + 2O2 -> CO2 + 2H2O + HR to convert the large amount of thermal energy that is released in the chemical reactions to mechanical work via heat engines (power plants). Understand the fundamental processes during chemical reactions Study the coupling between the heat release and thermo-fluid dynamics Historical perspectives Discovery of FIRE …. Long long time ago…. The use of combustion in technology dates back to: 100 A.D. (the development of metallurgy) 1000-1200 A.D. (pyrotechnic rockets and furnaces) 1300 A.D. (guns) 1600 A.D. (steam engine) Experimental scientific studies of combustion began about 1660 in the Oxford School of Chemistry by Robert Boyle and Robert Hooke Historical perspectives First modern definition of combustion in 1665 Against the ancient ideas that FIRE was one of the 4 basic elements An exerpt from Hooke in 1665: “…it seems resonable to think that there is no such thing as an Element of Fire…but that that shinning transient body which we call Flame, is nothing else but a mixture of Air, and volatile sulphureous parts of dissoluble or combustion bodies, which are acting upon each other whil’st they ascent.” Historical perspectives Refined definition of combustion by Antoine Lavoisier and later on by Claude L. Berthollet and John Dalton: interpreted combustion in terms of a form of oxidation Chemistry consideration In the late 1800’s, Otto and Diesel engines were developed Another mode of combustion, the phenomenon of detonations, was discovered by Bunsen, Mallard and LeChatelier (also independently by Berthelot and Vielle). The foundation of the modern Science of Combustion The basis for much of our understanding of combustion was developed in the middle of the century (1940’s), particularly by Zel’dovich, Schelkin, Frank-Kamenetskii and others. Motivation Why do we need to study combustion? Combustion has a great economic, social and technical importance Energy/power production (almost 90% of world energy still comes from combustion process) Environmental problems - pollution problem - global warming WHERE THE WORLD GETS ITS ENERGY? • Still Heavily rely on a Fossil-fuel based combustion system Supply and Demand Projections of world energy production into the 21st century • There is no denying that our fossil fuel supplies are dwindling; yet, our dependence upon them is as great as ever Combustion technology Tackle the problem from the demand side of the equation • Design automobile, jet engine, etc with better efficiency to reduce the fuel consumption Develop new fossil technologies • New resources? Require knowledge in combustion Motivation Why do we need to study combustion? Combustion has a great economic, social and technical importance Energy/power production (almost 90% of world energy still comes from combustion process) Environmental problems - pollution problem - global warming Sky view in Shanghai Environmental problems • Greenhouse gases emissions: Global warming Climate change • Damage from storms, floods, wildfires • Property losses from sea-level rise • Productivity of farms, forests, & fisheries • Livability of cities in summer • Geography of disease 1750, the beginning of the industrial revolution ENVIRONMENTAL PROBLEM The projected carbon emission in the next 30 years we will add 3x more CO2 emission than the previous 250 years! The possibility of global warming and serious climate change Figure. The likely increases in CO2 concentration over the next century corresponding to four of the IPCC emission scenarios. 2 x CO2 Computer simulations by the Princeton Geophysical Fluid Dynamics Lab for CO2 increases above preindustrial revolution levels: 2x CO2 : 5 – 8° F 4 x CO2 4x CO2 : 15-25° F Pre-industrial: ~275 ppm Today: ~380 ppm Combustion Research Combustion is a fascinating multi-disciplinary science Kinetics theory Computer simulations Thermodynamics Combustion Applied math (Asymptotic methods) Heat transfer Diagnostics & measurement Fluid mechanics Transport processes Prerequisites Thermodynamics I and II (Mech 341,351) Strong background in: • Thermodynamics: thorough understanding of different thermodynamics properties/relationship and laws of thermodynamics • Basic fluid dynamics concepts • Knowledge of calculus and numerical methods Course topics Combustion is a very broad topic: What are we going to study in this course? Course topics Basic questions: How much energy is released in a chemical reaction? When does a reaction reach equilibrium? How fast do reactions occur? How does a flame propagate? How does a flame become unstable and turbulent? How does a detonation propagate? What combustion parameters are important for industrial safety consideration? How does the combustion of gases, liquids and solids differ? Course topics Specifically, we will look into more details the following topics of combustion: Chemical thermodynamics Chemical kinetics conservation equations for multi-component reacting systems Premixed laminar flame theory Gaseous detonations Gaseous diffusion flames Combustion instability mechanisms Industrial safety considerations Droplet combustion References • K.K. Kuo (2005) Principles of Combustion, 2nd ed. John Wiley & Sons • Notes and assigned reading materials will be posted in the website • Additional references: I. Glassman (1996) Combustion, 3rd ed. Academic Press S.R. Turns (1996) An Introduction to Combustion, 2nd ed. McGraw Hill B. Lewis & von Elbe (1987) Combustion, Flame and Explosion of Gases, 3rd ed. Academic Press F. Williams (1985) Combustion Theory, Benjamin & Cummings C.K. Law (2005) Combustion Physics, Cambridge University Press • Write your own notebook Concordia University Evaluation scheme Midterm quiz Final quiz (closed book) Project - proposal/audit - report - presentation Concordia University 25% 45% 5% 20% 5% How to succeed in this course • Review your basic engineering subjects (e.g. thermodynamics, fluid mechanics, heat transfer) • Study class lectures, read the textbook and update your notebook regularly • Do the homework • Read literature on combustion and develop an interest in the subject. Try to write the main points down in your notebook (keep a good learning record) • Discuss and collaborate with your colleagues Most important, ENJOY this course Concordia University Quad Chart Source: http://www.canis.uiuc.edu/ Concordia University