AME 514. Applications of Combustion

Transcription

1 AME 514 Applications of Combustion Lecture 15: Future needs in combustion research Emerging Technologies in Reacting Flows (Lecture 3) Ø Applications of combustion (aka chemically reacting flow ) knowledge to other fields (Lecture 1) Ø Frontal polymerization Ø Bacteria growth Ø Inertial confinement fusion Ø Astrophysical combustion Ø New technologies (Lecture 2) Ø Transient plasma ignition Ø HCCI engines Ø Microbial fuel cells Ø Future needs in combustion research (Lecture 3) Ø 2014 Grand Challenges Workshop Ø Writing a proposal of your own Ø White paper 2 1

2 Grand Challenges Workshop (2014) Ø The combustion research community laments the plethora of incremental works - should we be doing something else? Ø What would be a good use of our time and resources? Ø This workshop was an experiment to address this question Ø Grass roots movement, not beholden to any industry or funding agency funded only by NSF Ø Our customers are ourselves (the combustion research community) particular those early in their career 3 Grand Challenges Workshop scope Ø Energy conversion - starting with chemical energy in the form of fuels (e.g. hydrocarbons, alcohols, hydrogen) or fuel carriers (e.g. borohydrides), how can one more effectively (e.g. energy density, power density, range, emissions, safety) obtain electrical, shaft or kinetic (propulsive) power, new materials or processing techniques, etc.? Ø PDR s opinion - significant progress results from discovering and applying new physical and chemical phenomena and their interactions; improved modeling of known physics and chemistry has significant practical value but rarely yields transformational progress 4 2

3 What is a valid Grand Challenge? Ø Model - NAE Grand Challenges: (though too broad for our humble community) Ø Must be transformative disruptive etc., not incremental Ø Must be actionable, i.e. specific enough to conceive and execute a plan and decide if it has been solved Ø If solved, results in the ability to do something useful that could not have been done before Ø Should be an action, e.g. Burn fast with less turbulence rather than a topic, e.g. Fast burning with less turbulence Ø Should not be white paper or quad chart with specific research plan (what to do, not how to do it) 5 What is a valid Grand Challenge? Ø Not too broad or narrow Ø Too broad: Understand turbulent combustion Ø OK: Burn fast with less turbulence Ø Too narrow: Use acoustics to burn faster Ø Improve not as compelling as a binary challenge, i.e. do something that cannot currently be done Ø Understand predict model etc. not sufficient what can you do better if you can model it? Ø If Edison had a perfect model of the light bulb, he still could not have invented the fluorescent lamp, LED or laser Ø Evaluated (go / no go) based on Ø Value to the community and society if solved Ø Feasibility Ø NOT on likelihood of an agency funding the work Ø NOT prioritized 6 3

4 The Grand Challenges 1. Develop more efficient engines by reducing heat loss Ø Heat loss is the biggest source of efficiency loss in engines Ø Insulation or coating of limited value bottleneck in heat transfer is from the gas to the cylinder wall, not across the wall Ø Need lower heat transfer coefficients, e.g. via low turbulence, but then how to burn fast enough? Transient Plasma Ignition or??? 2. Fabricate nanostructured devices using combustion Ø Many researchers make materials using combustion processes Ø Advantage is high throughput compared to other methods, but quality and purity are low Ø Making a functioning device (electrical, optical, chemical, mechanical) with the throughput of combustion processes would be a huge advancement 3. Develop cyber-connected combustion using Big Data Analytics Ø Every vehicle has many sensors connected to a computer and a data port; can be connected to The Cloud via a smartphone Ø Connect them all together make every vehicle on the road a moving combustion laboratory 7 The Grand Challenges 4. Integrate energy conversion and CO 2 capture Ø CO 2 production is the Achilles Heel of combustion Ø Current approach make CO 2 then figure out what to do with it how can we combine production and capture of CO 2 Ø Deep sea methane clathrates (CH H 2 O) could be reacted and replaced by CO 2 clathrates (CO 2 6 H 2 O) 5. Eliminate thermoacoustic instabilities Ø Gas turbine combustor performance limited by acoustic waves coupling to heat release, leads to runaway thermoacoustic instabilities Ø How to suppress? Active control of fuel, air, geometry? 6. Control reaction pathways (e.g. control radical pools via additives, plasmas,???) Ø HCCI engines: identify radical buffer (analogous to ph buffer) to allow slower combustion once reaction starts; probably must contain C, H, O, N atoms only Ø Superknock (Kalghatgi and Bradley, 2012) observed in small, turbocharged engines (e.g. Ford EcoBoost - thought to be due to catalytic effect metallic particles in oil! 8 4

5 The Grand Challenges 7. Create fuel-based sub-kw power systems (electrical or motive) Ø We ve covered this enough already (Lectures 4 6) 8. Predict and mitigate wildland fires in real time Ø Current wildland fire models are not real-time - can help with planning but not suppression Ø What is the minimum set of measurements and models required to help first responders use available resources most effectively? 9. Enable fuel, product and operational flexibility (omnivorous combustion) Ø Few combustion devices are fuel flexible, e.g. gasoline vs. Diesel Ø Traditional + new fuels biofuels, Fischer-Tropsch, Ø How to make fuel flexible? Premixed + nonpremixed (RCCI), thermal or plasma reforming, catalysis, 10. Incorporate nonequilibrium effects in prediction of explosions Ø Current models of explosions employ equilibrium models for kinetics, vibration/rotation Boltzmann distributions Ø Extremely high pressures, fast reactions, shock fronts in explosions not valid unknown effects on explosion behavior 9 Benefits to society Ø Energy efficiency and CO 2 reduction Ø Environmental quality Ø Affordable energy Ø Safety (fire and explosion protection) Ø Energy sustainability Ø Innovative manufacturing 10 5

6 Writing research proposals (1/4) 1. Have at least one good, novel, clever idea Business as usual proposals don t sell Review panels give a lot of credit to proposals that are new and innovative Panels try to find a reason to like proposals with a good idea, no matter what weaknesses might exist 2. Pose specific, testable hypotheses Don t say we will measure the effect of x on y etc. etc. Do say based on the material presented in the introduction, it is our hypothesis that y will decrease as x increases, until x reaches a critical value, after which y will increase Show that you have a specific idea and intend to test it 11 Writing research proposals (2/4) 3. Avoid the kitchen sink mentality Don t say, we will do detailed and extensive measurements of everything using every imaginable diagnostic tool and vary every possible experimental parameter - it suggests you don t know what s important Do say, here is the minimum set of measurements and conditions needed to test these hypotheses; if we have time and money left over, here are the cool things we will do afterwards 4. Explain your end game Many proposals don t say what they will do once they have the results and how it can be used to test a hypothesis 5. Don t dwell on past work Some proposers brag about what they ve done and don t get to the point of what they propose to do next until page 11 (out of 15 max.) 12 6

7 Writing research proposals (3/4) Summary - where s the beef? Ask yourself: What is the one most important idea in this proposal? What will be the one most important consequence if it is funded? and write the proposal to sell these points Get the panel curious about your idea, make the panel ask themselves, hmmm, I wonder what would happen? Suggested NSF proposal page budget # pages Topic 1 Introduction - what your topic is and why it is important 3 Previous work - what has been done in this area; complain about what knowledge is lacking 1 Objectives - very specifically what will you do and why it is better 1 Hypotheses - what you think will happen 5 Approach - how you will test these hypotheses experimental or computational apparatus, etc. 2 Closure - what you will do with the data once you have it 2 Broader impact applications of the research and educational merit 13 Writing research proposals (4/4) Panel dynamics Typically 8 panel members, 25 proposals Each proposal read by 3 reviewers 1 lead, 2 others Each reviewer discusses his/her opinion Entire panel gives comments / feedback Reviewers may revise comments based on panel discussion Proposals are ranked after all are discussed You must have a champion someone who believes in your proposal and is willing to argue for it Every panel has different personnel and different dynamics Learn these dynamics first-hand: ask relevant NSF program officer(s) for invitation to be on a review panel also looks good on your résumé 14 7

8 References Kalghatgi, G.T., Bradley, D. (2012). Pre-ignition and 'super-knock' in turbo-charged spark-ignition engines, Int. J. Engine Research, Vol. 13, pp (DOI / ) 15 8