HECToR-enabled Step Change in Turbulent Multiphase Combustion Simulation

Over the past few years, we have concentrated efforts on a relatively new class of turbulent multiphase combustion, that is, turbulent combustion diluted by a liquid phase. Such diluted combustion is different from the conventional spray combustion (e.g. in diesel engines) and has applications in several low-emission high-efficiency energy systems and fire safety. Through a systematic approach and a series of jounral and conference publications, we have established a computational prototype of the phenomena, which is generic, phenomena-rich, scientifically interesting yet computationally amenable (on HEC!) and efficient. HECToR Phases 2a and 2b offer unprecedented opportunities for advanced simulations in turbulent multiphase combustion. The new Baker system, in particular, will have a peak speed of about 340 Tflops and 60 TB available, which is anticipated to consist of 44,544 cores (2x12 core chips and 32GB memory per node) giving a theoretical peak of around 340TF.We aim to conduct landmark simulations of turbulent multiphase diluted combustion on HECToR in order to make a step change in our understanding of key phenomena and potentially optimize applications of the technology. On the Baker system, we will conduct DNS of turbulent combustion diluted by evaporating droplets in order of increasing size and sophistication on up to 12,000 cores. Thereafter, the Lattice Boltzmann Method will be dynamically coupled with DNS to form a multi-scale simulation of fully resolved droplets in turbulent combustion. The results will be published in top international journals, promising to advance fundamental knowledge and impact on society and industry in the longer term.

The project is a fundamental research that aims to advance the fundamental science of turbulent multiphase combustion by exploiting, in a timely way, the best capability computing service available in the UK. Generating and disseminating original, significant and fundamental findings are the main outcome during the project period. The best way to achieve research impact is to publish in top journals in the field. We aim to publish two or three papers in the top journals of the relevant fields: Journal of Fluid Mechanics, and Combustion and Flame. In the meantime, we believe our research outcome will be of sufficient fundamental interest to publish in Philosophical Transactions of the Royal Society and/or Science. In addition, two major international conferences during the project period have been selected for participation. Dissemination within the UK will benefit from the PI's roles in two on-going national HPC/HEC consortia: the Consortium on Computational Combustion for Engineering Applications (COCCFEA) and the UK Turbulence Consortium (UKTC). DNS databases will also be uploaded onto the COCCFEA website at http://www.coccfea.ac.uk/ for external access. Dissemination of results internationally will also be helped by our participation in the Spring School and Conference on Turbulent Combustion, 3-29 May, 2010, Stockholm (http://agenda.albanova.se/conferenceDisplay.py?confId=573). Over a longer term, exploitation of the research outcomes will be explored with our partners in the energy industry (E.ON Power Technology, Siemens and Rolls-Royce) and fire safety agencies (Building Research Establishment and Health and Safety Executives). The phenomena studied here are directly related to an important technology, turbulent combustion diluted by a liquid phase, which has applications in a range of zero and low-emission, high-efficiency power and energy systems as well as fire safety engineering. One application is water injection on an aeroengine to reduce NOx emissions (through reduced peak combustion temperatures), specific fuel consumption, and engine hot-section temperatures while maintaining constant thrust. Another application is in capturing the carbon emissions from combustion through burning fuels in pure oxygen instead of air - oxy-fuel combustion. A relatively new concept is the gas turbine (GT) - solid oxide fuel cell (SOFC) hybrid system, which can achieve an overall efficiency of over 70%, with a simultaneous reduction in NOx emissions. Such an hybrid system also involves turbulent combustion diluted by water. The development of these new generation low-emission high-efficiency power/energy systems requires extensive research and tests before being commercialized. Industry has increasingly exploited computational combustion tools for diagnostics and R & D. The ultimate goals are to conduct numerical experiments in place of laboratory tests and to harness the combustion processes for a wide range of applications in a predictable way in order to save the industry billions of pounds in the product developments. The results from the proposed research can inform designers directly or through other CFD tools which use the data from this study as benchmarks for tool development and validation. As an indication of potential economic and social benefits, the Aerospace America reported that between 1997 an 2007, the US airline industry improved fuel efficiency by 110%, saving 2.5 billion metric tons of green house gas, equivalent to removing 18.7 million cars from the road each year. Another indicator is that, according to Prof. Geoff Cox former Director of Fire Research Station, Building Research Establishment, the cost of fires worldwide is equivalent to 0.5 to 1.5 % of global GDP. Therefore, the fundamental research proposed could in the longer term make a big impact on the real world.