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You searched for +publisher:"Université Catholique de Louvain" +contributor:("Verhelst, Sebastian"). Showing records 1 – 2 of 2 total matches.

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Université Catholique de Louvain

1. Contino, Francesco. Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations.

Degree: 2011, Université Catholique de Louvain

In the global energy context, many solutions are suggested to change our energy dependence and solve our CO2 emission issues. For transportation, biofuels are mentioned as a possible alternative to fossil fuels. Yet many people argue that they could hardly replace oil. The low efficiency of the conversion from biomass to biofuels implies other main issues like land use and food competition. More simple conversion routes, using less energy-consuming steps, could be used. However, the major drawback is then the lack of compatibility with conventional engines. Instead of adapting the fuel to the engines, the opposite has been put forward recently with the homogeneous charge compression ignition (HCCI). This engine does not intrinsically rely on specific fuel properties. Given that a fairly homogeneous air-fuel mixture is prepared, it can be operated on a large range of fuels. In the first part of this thesis, we analyzed the esters produced from fermentable wastes by a biochemical process. We investigated experimentally the impact of these esters on the HCCI. In practice, the development of new engine concepts and the characterization of fuels rely more and more on numerical simulations. However, the accurate and comprehensive modelling of the highly nonlinear combustion processes of realistic fuels is extremely demanding. It requires detailed mechanisms that involve hundreds of chemical species and thousands of elementary reactions. The computational cost of these simulations is generally prohibitive. This implies, first, that fairly detailed CFD simulations can only include global mechanisms, which only describe the main steps of the combustion; and second, that very detailed reaction mechanisms are mainly limited to simplified systems. In the second part of this thesis, we developed a new method that significantly mitigates the computational burden of detailed chemistry in complex CFD simulations. The developed numerical method, named tabulation of dynamic adaptive chemistry (TDAC), speeds the CFD simulations up to 900 times with a very small simulation error compared to the direct numerical integration of the combustion mechanisms.

(FSA 3)  – UCL, 2011

Advisors/Committee Members: UCL - SST/IMMC/TFL - Thermodynamics and fluid mechanics, Jeanmart, Hervé, Gerin, Patrick, Winckelmans, Grégoire, Dias, Véronique, Bartosiewicz, Yann, Verhelst, Sebastian, Lucchini, Tommaso, Foucher, Fabrice.

Subjects/Keywords: HCCI; Ethyl ester; TDAC; ISAT; DAC; OpenFOAM

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Contino, F. (2011). Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations. (Thesis). Université Catholique de Louvain. Retrieved from http://hdl.handle.net/2078.1/75968

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Contino, Francesco. “Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations.” 2011. Thesis, Université Catholique de Louvain. Accessed July 21, 2019. http://hdl.handle.net/2078.1/75968.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Contino, Francesco. “Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations.” 2011. Web. 21 Jul 2019.

Vancouver:

Contino F. Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations. [Internet] [Thesis]. Université Catholique de Louvain; 2011. [cited 2019 Jul 21]. Available from: http://hdl.handle.net/2078.1/75968.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Contino F. Combustion in homogeneous charge compression ignition engines : experimental analysis using ethyl esters and development of a method to include detailed chemistry in numerical simulations. [Thesis]. Université Catholique de Louvain; 2011. Available from: http://hdl.handle.net/2078.1/75968

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Université Catholique de Louvain

2. Bhaduri, Subir Swaraj. Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation.

Degree: 2015, Université Catholique de Louvain

Biomass syngas needs to be cooled before being usable in a conventional spark- ignition engine, in order to avoid knock. The tar impurities of raw biomass syngas condense due to this cooling process, which leads to the clogging and subsequent damage of critical process parts. Thus, in addition to cooling, the syngas needs to be purified of the tars, which adds to the cost and complexity of the gasification power plant. A novel technique is being investigated where the syngas temperature is kept above the tar dew point (about 250◦C) throughout the process, and thus, tar condensation and its related problems can potentially be avoided. A Homogeneous Charge Compression Ignition (HCCI) engine is suitable for such an application. The objective of this thesis is to experimentally study HCCI combustion with biomass syngas at intake temperatures above the tar dew point. Chapter 1, reviews the broad context of gasification and the associated tar impurities, where it argues that the SI engine, due to its limited intake temperature flexibility, significantly contributes in the making of tars into problematic compounds. The novel method of using the HCCI engine at intake temperatures above the tar dew point is introduced, along with listing the multiple challenges foreseen with such an approach. Of these challenges, two are identified which forms the main experimental works described in this thesis. The test bench, which includes a 435cc single-cylinder air cooled engine, and the associated instruments are discussed in Chapter 2. Chapter 3 discusses the various post processing methods used during this work which computes the rate of heat release from the raw in-cylinder pressure data, along with a host of other parameters. Thereafter, the main experimental works are described in Chapters 4, 5 and 6. In a real-world scenario, the syngas composition varies with time. To understand the HCCI combustion in response to such variations, studies with artificial syngas compositions were carried out, as described in Chapter 4. In these experiments, the time component was omitted and the focus was on determining the impacts of various possible syngas compositions as well as operating conditions on the HCCI combustion. It was found that increasing H2 content of syngas advanced the combustion which lead to the undesirable pressure ringing (equivalent to knock in SI engines). At an intake temperature of 250◦C and intake pressure of 1.2 bar, a maximum IMEP of 2.8 bar and an Indicated Efficiency (IE) of 35% could be attained with dry and pure syngas compositions. Since the raw syngas would also contain water and tars, the effects of these components were studied. Syngas moisture dampened the HCCI combustion, thus improving the IMEP potential. Two representative tar com- pounds (naphthalene and toluene) were used and it was observed that tars, due to their high heating values and higher heat capacities, had positive effects on HCCI combustion. Additionally, the effects of intake pressure and temperature were also studied with the conclusion that… Advisors/Committee Members: UCL - Ecole Polytechnique de Louvain, UCL - SST/IMMC/TFL - Thermodynamics and fluid mechanics, Jeanmart, Hervé, Bartosiewicz, Yann, Johansson, Bengt, Verhelst, Sebastian, Contino, Francesco, Winckelmans, Grégoire.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Bhaduri, S. S. (2015). Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation. (Thesis). Université Catholique de Louvain. Retrieved from http://hdl.handle.net/2078.1/165271

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Bhaduri, Subir Swaraj. “Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation.” 2015. Thesis, Université Catholique de Louvain. Accessed July 21, 2019. http://hdl.handle.net/2078.1/165271.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Bhaduri, Subir Swaraj. “Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation.” 2015. Web. 21 Jul 2019.

Vancouver:

Bhaduri SS. Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation. [Internet] [Thesis]. Université Catholique de Louvain; 2015. [cited 2019 Jul 21]. Available from: http://hdl.handle.net/2078.1/165271.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Bhaduri SS. Experimental studies on HCCI combustion of biomass syngas towards tar tolerant operation. [Thesis]. Université Catholique de Louvain; 2015. Available from: http://hdl.handle.net/2078.1/165271

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.