Implementation of Active Methodologies in International Relations Through Cinema: Experience From Project-Based Learning in Graduate School

The article describes the results of the educational innovation project “Implementation of active methodologies in the Master’s Degree in International Journalism through cinema”,1 which aims to develop the transversal lines of the Master’s Degree in International Journalism based on the application of innovative tools in subjects of Module I and II, as well as to enhance sensitivity and awareness of Cultural Diversity and Human Rights. The methodology used is discussion through the Cinema-Forum format and pre- and post-forum questionnaires are used to evaluate the results. As a conclusion, it can be deduced that the film-forum is a tool that enables the development of transversal competencies based on the interaction process resulting from the activity as an effective complement to graduate courses in the discipline of International Relations

Importance of food sensitivities and personalized diet in patients with fibromyalgia

Fibromyalgia (FM) is a disease characterized by generalized chronic pain located in the locomotor system. Patients usually present obesity, metabolic syndrome, alterations in the microbiota and food sensitivities. The prevalence is 2.1% in the world population, affecting 2.3% of Europeans and 2.4% of Spaniards. By sex, the prevalence among men is estimated at 0.2%, compared to 4.2% in women. FM is one of the rheumatic diseases with more impact on the quality of life. Nutrition has been suggested as a relevant factor in the treatment and improvement of FM symptoms. The aim of this study was to measure mitochondrial homeostasis using several biomarkers for the diagnosis and monitoring of FM before and after the application of a personalized nutritional intervention with a rich antioxidant diet. Furthermore, we  evaluated the role of personalized nutrition as a potential treatment for patients with FM and identified new approaches for a better understanding of the disease.Motivation: Currently, a significant percentage of patients who suffer FM are not well diagnosed and face inadequate treatments. We proposed that personalized nutritional interventions can improve the symptomatology of patients and their quality of life.Methods: Fifty FM patients with clinical suspicion of food sensitivities were included in the study. Data were collected from nutritional questionnaries, the Fibromyalgia Impact Questionnaire (FIQ) and the ratio of mitochondrial mass and selective autophagy. Mitochondrial markers were measured pre and post nutritional interventions with the objective of evaluating if personalized diets improved clinical symptoms.Results: Rich antioxidant diets decreased radical oxygen species (ROS) levels in blood and improved significantly clinical symptoms. In addition, a balanced, personalized diet for each patient improved the ratio between mitochondrial mass and selective autophagy.Conclusions: FM patients presents several associated comorbidities such as food sensitivities which need more attention and research. The adequate consumption of antioxidants and other micronutrients is important in FM management. Therefore,  personalized antioxidant diets could be a promising approach for the improvement of clinical symptoms in FM

Assessment on the consequences of injection strategies on combustion process and particle size distributions in Euro VI medium-duty diesel engine

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419865652.[EN] Although there are already several works where the influence of injection parameters on exhaust emissions, and specifically on particulate matter emissions, in diesel engines has been evaluated, the diversity in the results that can be found in the literature indicates the need to carry out new experiments that can provide more information about the influence of these parameters on modern diesel engines. This study intends to be placed within this scientific framework, hence a parametric study was carried out based on the independent modification of the main injection timing and the injection pressure with respect to the nominal conditions of a new Euro VI direct injection diesel engine. Four steady-state operation points of the engine map were chosen: 25% load and 950 r/min, 50% load and 1500 r/min, 75% load and 2000 r/min and 100% load and 2200 r/min, where in each of these operation points, the variations of the injection parameters in the study on the combustion process and its consequent impact on the particle size distribution, including an analysis of the geometric mean diameter values, were evaluated. The results showed that the different injection strategies adopted, despite not significantly affecting the engine efficiency, did cause a significant impact on particle number emissions. At the low load operation, the size distribution showed a bimodal structure, and as the main injection timing was delayed and the injection pressure was decreased, the nucleation-mode particle concentration decreased, while the accumulation-mode particle concentration increased. In addition, at medium load, the nucleation-mode particle emission decreased considerably while the accumulation-mode particle emission increased, and this increase was much greater with the main injection timing delay and the injection pressure reduction. Similar behavior was observed at high load, but with a much more prominent pattern.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This investigation has been funded by VOLVO Group Trucks Technology. The authors also acknowledge the Spanish economy and competitiveness ministry for partially supporting this research (HiReCo TRA2014-58870-R).Bermúdez, V.; García Martínez, A.; Villalta-Lara, D.; Soto, L. (2020). Assessment on the consequences of injection strategies on combustion process and particle size distributions in Euro VI medium-duty diesel engine. International Journal of Engine Research. 21(4):683-697. https://doi.org/10.1177/1468087419865652683697214Kemball-Cook, S., Yarwood, G., Johnson, J., Dornblaser, B., & Estes, M. (2015). Evaluating NOx emission inventories for regulatory air quality modeling using satellite and air quality model data. Atmospheric Environment, 117, 1-8. doi:10.1016/j.atmosenv.2015.07.002Paulin, L., & Hansel, N. (2016). Particulate air pollution and impaired lung function. F1000Research, 5, 201. doi:10.12688/f1000research.7108.1Hime, N., Marks, G., & Cowie, C. (2018). A Comparison of the Health Effects of Ambient Particulate Matter Air Pollution from Five Emission Sources. International Journal of Environmental Research and Public Health, 15(6), 1206. doi:10.3390/ijerph15061206Johnson, T., & Joshi, A. (2018). Review of Vehicle Engine Efficiency and Emissions. SAE International Journal of Engines, 11(6), 1307-1330. doi:10.4271/2018-01-0329Wu, Z., Rutland, C. J., & Han, Z. (2017). Numerical optimization of natural gas and diesel dual-fuel combustion for a heavy-duty engine operated at a medium load. International Journal of Engine Research, 19(6), 682-696. doi:10.1177/1468087417729255Lapuerta, M., Hernández, J. J., Rodríguez-Fernández, J., Barba, J., Ramos, A., & Fernández-Rodríguez, D. (2017). Emission benefits from the use of n-butanol blends in a Euro 6 diesel engine. International Journal of Engine Research, 19(10), 1099-1112. doi:10.1177/1468087417742578Chilumukuru, K., Gupta, A., Ruth, M., Cunningham, M., Kothandaraman, G., Cumaranatunge, L., & Hess, H. (2017). Aftertreatment Architecture and Control Methodologies for Future Light Duty Diesel Emission Regulations. SAE International Journal of Engines, 10(4), 1580-1587. doi:10.4271/2017-01-0911Bermúdez, V., Luján, J. M., Piqueras, P., & Campos, D. (2014). Pollutants emission and particle behavior in a pre-turbo aftertreatment light-duty diesel engine. Energy, 66, 509-522. doi:10.1016/j.energy.2014.02.004Lapuerta, M., Ramos, Á., Fernández-Rodríguez, D., & González-García, I. (2018). High-pressure versus low-pressure exhaust gas recirculation in a Euro 6 diesel engine with lean-NOx trap: Effectiveness to reduce NOx emissions. International Journal of Engine Research, 20(1), 155-163. doi:10.1177/1468087418817447Rakopoulos, C. D., Rakopoulos, D. C., Mavropoulos, G. C., & Kosmadakis, G. M. (2018). Investigating the EGR rate and temperature impact on diesel engine combustion and emissions under various injection timings and loads by comprehensive two-zone modeling. Energy, 157, 990-1014. doi:10.1016/j.energy.2018.05.178Du, W., Lou, J., Yan, Y., Bao, W., & Liu, F. (2017). Effects of injection pressure on diesel sprays in constant injection mass condition. Applied Thermal Engineering, 121, 234-241. doi:10.1016/j.applthermaleng.2017.04.075Nishida, K., Zhu, J., Leng, X., & He, Z. (2017). Effects of micro-hole nozzle and ultra-high injection pressure on air entrainment, liquid penetration, flame lift-off and soot formation of diesel spray flame. International Journal of Engine Research, 18(1-2), 51-65. doi:10.1177/1468087416688805Yamasaki, Y., Ikemura, R., & Kaneko, S. (2017). Model-based control of diesel engines with multiple fuel injections. International Journal of Engine Research, 19(2), 257-265. doi:10.1177/1468087417747738Giechaskiel, B., Schiefer, E., Schindler, W., Axmann, H., & Dardiotis, C. (2013). Overview of Soot Emission Measurements Instrumentation: From Smoke and Filter Mass to Particle Number. SAE International Journal of Engines, 6(1), 10-22. doi:10.4271/2013-01-0138Dickau, M., Olfert, J., Stettler, M. E. J., Boies, A., Momenimovahed, A., Thomson, K., … Johnson, M. (2016). Methodology for quantifying the volatile mixing state of an aerosol. Aerosol Science and Technology, 50(8), 759-772. doi:10.1080/02786826.2016.1185509Lähde, T., Rönkkö, T., Virtanen, A., Schuck, T. J., Pirjola, L., Hämeri, K., … Keskinen, J. (2008). Heavy Duty Diesel Engine Exhaust Aerosol Particle and Ion Measurements. Environmental Science & Technology, 43(1), 163-168. doi:10.1021/es801690hSaxena, M. R., & Maurya, R. K. (2017). Effect of premixing ratio, injection timing and compression ratio on nano particle emissions from dual fuel non-road compression ignition engine fueled with gasoline/methanol (port injection) and diesel (direct injection). Fuel, 203, 894-914. doi:10.1016/j.fuel.2017.05.015Gao, J., & Kuo, T.-W. (2018). Toward the accurate prediction of soot in engine applications. International Journal of Engine Research, 20(7), 706-717. doi:10.1177/1468087418773937Zhang, Y., Ghandhi, J., & Rothamer, D. (2017). Comparisons of particle size distribution from conventional and advanced compression ignition combustion strategies. International Journal of Engine Research, 19(7), 699-717. doi:10.1177/1468087417721089Lapuerta, M., Armas, O., & Gómez, A. (2003). Diesel Particle Size Distribution Estimation from Digital Image Analysis. Aerosol Science and Technology, 37(4), 369-381. doi:10.1080/02786820300970Agarwal, A. K., Gupta, T., & Kothari, A. (2011). Particulate emissions from biodiesel vs diesel fuelled compression ignition engine. Renewable and Sustainable Energy Reviews, 15(6), 3278-3300. doi:10.1016/j.rser.2011.04.002Bai, J., & Qiao, X. (2015). Crankcase gaseous and particle emissions in common rail diesel engine. International Journal of Engine Research, 17(2), 179-192. doi:10.1177/1468087414563585Reijnders, J., Boot, M., & de Goey, P. (2018). Particle nucleation-accumulation mode trade-off: A second diesel dilemma? Journal of Aerosol Science, 124, 95-111. doi:10.1016/j.jaerosci.2018.06.013Bonatesta, F., Chiappetta, E., & La Rocca, A. (2014). Part-load particulate matter from a GDI engine and the connection with combustion characteristics. Applied Energy, 124, 366-376. doi:10.1016/j.apenergy.2014.03.030Desantes, J. M., Bermúdez, V., García, A., & Linares, W. G. (2011). A Comprehensive Study of Particle Size Distributions with the Use of PostInjection Strategies in DI Diesel Engines. Aerosol Science and Technology, 45(10), 1161-1175. doi:10.1080/02786826.2011.582898Li, X., Guan, C., Luo, Y., & Huang, Z. (2015). Effect of multiple-injection strategies on diesel engine exhaust particle size and nanostructure. Journal of Aerosol Science, 89, 69-76. doi:10.1016/j.jaerosci.2015.07.008Benajes, J., García, A., Monsalve-Serrano, J., Balloul, I., & Pradel, G. (2017). Evaluating the reactivity controlled compression ignition operating range limits in a high-compression ratio medium-duty diesel engine fueled with biodiesel and ethanol. International Journal of Engine Research, 18(1-2), 66-80. doi:10.1177/1468087416678500Kakaee, A.-H., Nasiri-Toosi, A., Partovi, B., & Paykani, A. (2016). Effects of piston bowl geometry on combustion and emissions characteristics of a natural gas/diesel RCCI engine. Applied Thermal Engineering, 102, 1462-1472. doi:10.1016/j.applthermaleng.2016.03.162Desantes, J. M., Bermúdez, V., Pastor, J. V., & Fuentes, E. (2004). Methodology for measuring exhaust aerosol size distributions from heavy duty diesel engines by means of a scanning mobility particle sizer. Measurement Science and Technology, 15(10), 2083-2098. doi:10.1088/0957-0233/15/10/019Desantes, J. M., Bermúdez, V., Molina, S., & Linares, W. G. (2011). Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions. Measurement Science and Technology, 22(11), 115101. doi:10.1088/0957-0233/22/11/115101Payri, F., Olmeda, P., Martín, J., & García, A. (2011). A complete 0D thermodynamic predictive model for direct injection diesel engines. Applied Energy, 88(12), 4632-4641. doi:10.1016/j.apenergy.2011.06.005Benajes, J. V., López, J. J., Novella, R., & García, A. (2008). ADVANCED METHODOLOGY FOR IMPROVING TESTING EFFICIENCY IN A SINGLE-CYLINDER RESEARCH DIESEL ENGINE. Experimental Techniques, 32(6), 41-47. doi:10.1111/j.1747-1567.2007.00296.xLiu, Q., Fu, J., Zhu, G., Li, Q., Liu, J., Duan, X., & Guo, Q. (2018). Comparative study on thermodynamics, combustion and emissions of turbocharged gasoline direct injection (GDI) engine under NEDC and steady-state conditions. Energy Conversion and Management, 169, 111-123. doi:10.1016/j.enconman.2018.05.047Seong, H. J., & Boehman, A. L. (2012). Studies of soot oxidative reactivity using a diffusion flame burner. Combustion and Flame, 159(5), 1864-1875. doi:10.1016/j.combustflame.2012.01.009Desantes, J. M., Bermúdez, V., García, J. M., & Fuentes, E. (2005). Effects of current engine strategies on the exhaust aerosol particle size distribution from a Heavy-Duty Diesel Engine. Journal of Aerosol Science, 36(10), 1251-1276. doi:10.1016/j.jaerosci.2005.01.002Lucachick, G., Curran, S., Storey, J., Prikhodko, V., & Northrop, W. F. (2016). Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines. Aerosol Science and Technology, 50(5), 436-447. doi:10.1080/02786826.2016.1163320Mohankumar, S., & Senthilkumar, P. (2017). Particulate matter formation and its control methodologies for diesel engine: A comprehensive review. Renewable and Sustainable Energy Reviews, 80, 1227-1238. doi:10.1016/j.rser.2017.05.133Burtscher, H. (2005). Physical characterization of particulate emissions from diesel engines: a review. Journal of Aerosol Science, 36(7), 896-932. doi:10.1016/j.jaerosci.2004.12.00

Exploring the limits of the reactivity controlled compression ignition combustion concept in a light-duty diesel engine and the influence of the direct-injected fuel properties

[EN] This experimental work investigates the operational limits of the reactivity controlled compression ignition combustion concept in a light-duty single-cylinder diesel engine using the stock compression ratio (17.1:1) with specific constraints. In addition, the effects of using different direct-injected fuels on engine-out emissions and performance are analyzed. First, an engine mapping was performed using diesel and gasoline as direct-injected and port-injected fuels, respectively. The operational limits of the reactivity controlled compression ignition concept have been found to be confined in the region defined from 2 to 5 bar indicated mean effective pressure at 1000 rev/min and from 4 to 8 bar indicated mean effective pressure at 3000 rev/min. In that portion of the map, nitrogen oxides and smoke emissions were below 0.4 g/kW h and 0.1 filter smoke number simultaneously, and the engine mechanical limits were respected. Later, the effects of the direct-injected fuel properties have been evaluated at the points that define the frontiers of maximum and minimum engine load in the baseline engine map (diesel/gasoline). To do this, three additional fuels based on diesel-gasoline mixings at different ratios (90%-10%, 70%-30% and 50%-50%), also known as dieseline, were used as direct-injected fuel instead of 100% diesel. To isolate the effects of each direct-injected fuel, the same engine settings were used for the comparison. The results show that, as the reactivity gradient between the high and low reactivity fuel diminishes, the sequential autoignition achieved in reactivity controlled compression ignition due to local combustion reactions switches to a more kinetically controlled homogeneous charge compression ignition-like combustion process. Finally, all the fuels were found to be capable of operating inside the emissions restrictions imposed by doing little modifications on the baseline calibration. However, no clear potential was found versus using 100% diesel as high-reactivity fuel.The authors gratefully acknowledge General Motors Global Research & Development for providing the engine used in this investigation. The authors also acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through HiReCo project (TRA2014-58870-R). The author J. Monsalve-Serrano acknowledges the financial support from the Universitat Politecnica de Valencia under the grant "Ayudas Para la Contratacion de Doctores para el Acceso al Sistema Espanol de Ciencia, Tecnologia e Innovacion".Benajes, J.; García Martínez, A.; Monsalve-Serrano, J.; Villalta-Lara, D. (2018). Exploring the limits of the reactivity controlled compression ignition combustion concept in a light-duty diesel engine and the influence of the direct-injected fuel properties. Energy Conversion and Management. 157:277-287. https://doi.org/10.1016/j.enconman.2017.12.028S27728715

A new small supernumerary marker chromosome, generating mosaic pure trisomy 16q11.1–q12.1 in a healthy man

Here we report on a healthy and fertile 30 years old man, who was carrier of a small supernumerary marker chromosome (sSMC). The application of molecular techniques such as fluorescence in situ hybridisation (FISH), microdissection and reverse painting, helped to characterize the sSMC which resulted to be derived from chromosome 16. In fact, the presence of euchromatin material from the long arm (16q) in the sSMC was demonstrated, and the karyotype can be written as mos 47, XY,+min(16)(:p11.1->q12.1:)[20]/46, XY [10]

Swirl ratio and post injection strategies to improve late cycle diffusion combustion in a light-duty diesel engine

[EN] Nitrogen oxides (NOx) and soot emissions are the most important pollutants from direct-injection diesel engines. In particular, soot formation and oxidation determine the net engine-out soot emissions. These phenomena are complex and competing processes during diesel combustion. Despite many researches implicate the mechanisms of soot formation with soot emissions, the enhancement of the late cycle soot oxidation is the dominant mechanism for a reduction of engine-out soot emissions. The mixing process and the in-cylinder bulk temperature are two important parameters in the development of soot oxidation process. The current research compares different engine strategies to enhance the late cycle mixing controlled combustion process and therefore enhance soot oxidation while maintaining similar gross indicated efficiency in a light-duty engine. For this purpose, a simplified methodology has been used, which analyzes the effect of mixing process and in-cylinder bulk gas temperature on soot oxidation during the late cycle combustion. For carrying out this research, theoretical and experimental tools were used. In particular, the experimental measurements were made in a single-cylinder direct-injection light-duty diesel engine varying the swirl ratio and the injection pattern as injection pressure, Start of Energizing (SoE), Energizing Time (ET) and number of injections events. To analyze soot emissions, the combustion luminosity was measured by an optoelectronic probe and the optical thickness parameter (KL) was evaluated by the two-color pyrometry method. The apparent combustion time (ACT-1) was used as mixing time tracer. Results show that an increase in swirl ratio implies an improvement on the mixing process and higher values of average bulk temperature during the late-cycle diffusion combustion. Both phenomena produce an enhancement in the soot oxidation process. In the lowest swirl ratio case, a suitable injection strategy based on multiple injections, provides similar results of soot oxidation process (and therefore, the emissions) as high swirl ratio case. (C) 2017 Elsevier Ltd. All rights reserved.Benajes, J.; Martín, J.; García Martínez, A.; Villalta-Lara, D.; Warey, A. (2017). Swirl ratio and post injection strategies to improve late cycle diffusion combustion in a light-duty diesel engine. Applied Thermal Engineering. 123:365-376. doi:10.1016/j.applthermaleng.2017.05.101S36537612

Performance of a conventional diesel aftertreatment system used in a medium-duty multi-cylinder dual-mode dual-fuel engine

[EN] Dual-mode dual-fuel combustion stands as one of the promising techniques to allow the dual-fuel operation along the whole engine map. This concept relies on using different combustion strategies as reactivity controlled compression ignition up to medium load, then migrating to diffusive dual-fuel combustion to reach full load. With this strategy, it is possible to obtain sensible reductions in NOx and soot while providing improvements in fuel consumption and CO2 emissions. However, the excessive quantities of HC and CO together with the low exhaust temperature can compromise the diesel oxidation catalyst (DOC) efficiency. In addition, the diffusive dual-fuel combustion applied at high engine load produces considerable soot amounts that should be reduced within the diesel particulate filter (DPF). Based on these facts, this work intends to evaluate the efficiency of a commercial aftertreatment system (DOC¿+¿DPF) while operating in dual-mode dual-fuel combustion. Additionally, fundamental studies where developed to understand the impact of the combination of fuels on the exhaust hydrocarbon species. First, the DOC performance was evaluated at steady-state and transient conditions under different operating conditions fulfilling the EUVI NOx and soot limits. In parallel, the different engine-out hydrocarbon species were measured by means of a Fourier-transform infrared spectroscopy (FTIR) gas analyzer. Finally, the passive and active regeneration processes were assessed by means of different methodologies aiming to evaluate the low NOx-low soot interaction and the capability of the active regeneration in dual-fuel dual-mode (DMDF) operating conditions. The DOC results showed an improper conversion efficiency at low load operating condition, where the exhaust temperature is low. By contrast, the thermal inertia at transient conditions allowed to improve the DOC behavior at low load, reaching DOC-out emissions one order of magnitude lower than those from the steady-state tests. Concerning the DPF, it was demonstrated that the low concentration of NOx and soot produced during the combustion does not lead to sensible changes in the NO2/NOx ratio before and after the DPF, indicating a low level/absence of passive regeneration. In the case of the active regeneration, both conventional diesel combustion (CDC) and DMDF operating conditions can obtain satisfactory reduction in the total soot trapped, being the increase in the exhaust temperature consequence of the HC and CO conversion the supporting mechanism for the active regeneration in the DMDF concept.The authors thanks VOLVO Group Trucks Technology and ARAMCO Overseas Company for supporting this research. The authors also acknowledge FEDER and Spanish Ministerio de Economía y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R).García Martínez, A.; Monsalve-Serrano, J.; Villalta-Lara, D.; Lago-Sari, R. (2019). Performance of a conventional diesel aftertreatment system used in a medium-duty multi-cylinder dual-mode dual-fuel engine. Energy Conversion and Management. 184:327-337. https://doi.org/10.1016/j.enconman.2019.01.069S32733718

Fuel sensitivity effects on dual-mode dual-fuel combustion operation for different octane numbers

[EN] The dual-mode dual-fuel combustion is a promising combustion concept to achieve the required emissions and carbon dioxide reductions imposed by the next emissions standards. Nonetheless, since the combustion concept relies on the reactivity of two different fuels (diesel and gasoline), the fuel formulation requirements are stricter. This work investigates the effects of the low reactivity fuel sensitivity for different octane numbers at different operating conditions representative of the combustion regimes found inside the dual-mode dual-fuel engine map. For this, experimental evaluations were performed using fuels with research octane number 92.5 and 80 and different sensitivities (0, 5 and the maximum one achievable for each fuel). The combustion development was assessed by means of the heat release rate characterization. Moreover, numerical simulations in a constant volume homogeneous reactor were used to explore and understand the impact of the different fuels on the ignition delay time. The results suggest that the sensitivity increase affects the different research octane number fuels in a different way. For the fuel with research octane number 92.5, the sensitivity variation increases the experimental ignition delay, impairing the combustion process and increasing the fuel consumption. In the case of the fuel with research octane number 80, the sensitivity increase does not affect the combustion development. This was justified by the numerical investigation, which points to a wider temperature range where the sensitivity does not affect the final ignition delay for research octane number 80. Moreover, generally, the ignition delay times for research octane number 80 considering the experimental gasoline fraction used are half than those of research octane number 92.5. At full load conditions, the trend is inverted, where the experimental ignition delay for research octane number 80 is affected by the sensitivity whilst research octane number 92.5 presents only modifications after the combustion start.The authors thanks ARAMCO Overseas Company and VOLVO Group Trucks Technology for supporting this research. The authors also acknowledge FEDER and Spanish Ministerio de Economía y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R), and the Universitat Politècnica de València for partially supporting this research through Convocatoria de ayudas a Primeros Proyectos de Investigación (PAID-06-18).García Martínez, A.; Monsalve-Serrano, J.; Villalta-Lara, D.; Lago-Sari, R. (2019). Fuel sensitivity effects on dual-mode dual-fuel combustion operation for different octane numbers. Energy Conversion and Management. 201:1-13. https://doi.org/10.1016/j.enconman.2019.112137S11320

Octane number influence on combustion and performance parameters in a Dual-Mode Dual-Fuel engine

[EN] Low temperature combustion stands as a promising alternative to realize low soot and NOx emissions while achieving fuel consumption benefits compared to the conventional diesel combustion. Nonetheless, its applicability is limited to narrow zones inside the engine map, reducing the potential benefits on a real driving case. In this scenario, the use of dual-mode dual-fuel combustion stands as an alternative to cover engine conditions up to full load, avoiding the constraints of the fully premixed combustion whenever is needed. This combustion concept is strongly influenced by the characteristics of the fuels that are used to create the charge stratification during the engine operation. The current research aims to evaluate the influence of the low reactivity fuel octane number on the combustion process and the average performance and emissions results. Additionally, the best octane number was determined by means of a merit function evaluation. Octane values of 100, 92.5, 87.5, 85 and 80 were obtained by blending iso-octane and heptane. Their performance was assessed in a medium-duty multi-cylinder platform at different representative operating conditions. The results suggest that fuels with octane number lower than 92.5 have a low impact at low load conditions. However, as load is increased, the high reactivity of the low research octane number fuels leads to early combustion processes, demanding settings modifications to avoid the appearance of excessive pressure gradients. As a consequence of these modifications, the fuel consumption and soot emissions increase. In general, RONs from 92.5 to 87.5 are less penalized, presenting the best merit function values, and therefore being the best fuels to be used in the hardware under investigation.The authors thanks VOLVO Group Trucks Technology and ARAMCO Overseas Company for supporting this research. The authors also acknowledge FEDER and Spanish Ministerio de Economía y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R) and the Universitat Politècnica de València for partially supporting this research through Convocatoria de ayudas a Primeros Proyectos de Investigación (PAID-06-18).García Martínez, A.; Monsalve-Serrano, J.; Villalta-Lara, D.; Lago-Sari, R. (2019). Octane number influence on combustion and performance parameters in a Dual-Mode Dual-Fuel engine. Fuel. 258:1-11. https://doi.org/10.1016/j.fuel.2019.116140S11125