A RCCI operational limits assessment in a medium duty compression ignition engine using an adapted compression ratio

Reactivity Controlled Compression Ignition concept offers an ultra-low nitrogen oxide and soot emissions with a high thermal efficiency. This work investigates the capabilities of this low temperature combustion concept to work on the whole map of a medium duty engine proposing strategies to solve its main challenges. In this sense, an extension to high loads of the concept without exceeding mechanical stress as well as a mitigation of carbon oxide and unburned hydrocarbons emissions at low load together with a fuel consumption penalty have been identified as main Reactivity Controlled Compression Ignition drawbacks. For this purpose, a single cylinder engine derived from commercial four cylinders medium-duty engine with an adapted compression ratio of 12.75 is used. Commercial 95 octane gasoline was used as a low reactivity fuel and commercial diesel as a high reactivity fuel. Thus, the study consists of two different parts. Firstly, the work is focused on the development and evaluation of an engine map trying to achieve the maximum possible load without exceeding a pressure rise rate of 15 bar/CAD. The second part holds on improving fuel consumption and carbon oxide and unburned hydrocarbons emissions at low load. Results suggest that it is possible to achieve up to 80% of nominal conventional diesel combustion engine load without overpassing the constraints of pressure rise rate (below 15 bar/CAD) and maximum pressure peak (below 190 bar) while obtaining ultra-low levels of nitrogen oxide and soot emissions. Regarding low load challenges, it has developed a particular methodology sweeping the gasoline-diesel blend together with intake temperature or exhaust gas recirculation maintaining constant the combustion phasing and ultra-low nitrogen oxide and soot emissions. As a result a drastic decrease carbon oxide and unburned hydrocarbons emissions is obtained with a slight fuel consumption improvement.The authors would like to thank VOLVO Group Trucks Technology for supporting this research.Benajes Calvo, JV.; Pastor Soriano, JV.; García Martínez, A.; Boronat-Colomer, V. (2016). A RCCI operational limits assessment in a medium duty compression ignition engine using an adapted compression ratio. Energy Conversion and Management. 126:497-508. doi:10.1016/j.enconman.2016.08.023S49750812

Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load

Along the last years, engine researchers are more and more focusing their efforts on the advanced low temperature combustion (LTC) concepts with the aim of achieving the stringent limits of the current emission legislations. In this regard, several studies based on highly premixed combustion concepts such as HCCI has been confirmed as a promising way to decrease drastically the most relevant CI diesel engine-out emissions, NOx and soot. However, the major HCCI drawbacks are the narrow load range, bounded by either misfiring (low load, low speed) or hardware limitations (higher load, higher speeds) and the combustion control (cycle-to-cylce control and combustion phasing). Although several techniques have been widely investigated in order to overcome these drawbacks, the high chemical reactivity of the diesel fuel remains as the main limitation for the combustion control. The attempts of the researchers to overcome these disadvantages are shifting to the use of fuels with different reactivity. In this sense, gasoline PPC has been able to reduce emissions and improve efficiency simultaneously, but some drawbacks regarding controllability and stability at low load operating conditions still need solution. In this field, previous researches have been demonstrate the multiple injection strategy as an appropriate technique to enhance the combustion stability. However, PPC combustion has been found limited to engine loads higher than 5 bar BMEP when using fuels with octane number greater than 90. In this regard, previous work from the authors showed the capability of the spark plug to provide combustion control in engine loads below this limit even using 98 ON gasoline. The main objective of the present work is to couple the control capability of the spark assistance together with an appropriate mixture distribution by using double injection strategies with the aim of evaluating performance and engine-out emissions at low load PPC range using a high octane number gasoline. For this purpose the optical and metal version of a compression ignition single-cylinder engine, to allow high compression ratio, has been used during the research. A common rail injection system enabling high injection pressures has been utilized to supply the 98 octane number gasoline. An analysis of the in-cylinder pressure signal derived parameters, hydroxyl radical (OH*) and natural luminosity images acquired from the transparent engine as well as a detailed analysis of the air/fuel mixing process by means of a 1-D in-house developed spray model (DICOM) has been conducted. Results from both analysis methods, suggest the spark assistance as a proper technique to improve the spatial and temporal control over the low load gasoline PPC combustion process. A noticeable increase in the cycle to cycle repeatability (5% versus 15.1% CoV IMEP at 2 bar load) as well as a reduction in the knocking level (20.5 versus 33.6 MW/m2 at 7 bar load) is observed. In addition, the combination of the spark assistance with the use of the double injection strategy provides a great improvement in terms of combustion efficiency (93% versus 88% for a single injection strategy) with a benefit around 18% in the IMEPBenajes Calvo, JV.; Tormos Martínez, BV.; García Martínez, A.; Monsalve Serrano, J. (2014). Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load. SAE International Journal of Engines. 7(4):1875-1887. doi:10.4271/2014-01-2669S187518877

The role of in-cylinder gas density and oxygen concentration on late spray mixing and soot oxidation processes

An analysis of in-cylinder gas density and oxygen mass concentration (YO 2) impact on the mixing and oxidation processes and the final soot emissions in conventional high temperature diffusive Diesel combustion conditions is presented in this paper. Parametrical tests were performed on a single cylinder heavy duty research engine. The density was modified adjusting the boost pressure following two approaches, maintaining the YO 2 either before or after the combustion process. The YO 2 was modified by diluting fresh air with exhaust gas maintaining a constant density. The possibility of controlling the soot emissions combining both parameters (YO 2 and density) is evaluated and, in a final part, the NO X emission results are also addressed. Results show that YO 2 has a strong effect on both mixing and oxidation processes while density affects principally the mixing process. Both parameters affect the final soot emissions. The density modification through adjustment of boost pressure modifies the trapped mass and has a strong impact on the evolution of YO 2 (thus on the evolution of the mixing process) during combustion. If the density is increased maintaining constant the YO 2 at the beginning of the combustion, the NO X-Soot trade-off is enhanced. © 2011 Elsevier Ltd.Benajes Calvo, JV.; Novella Rosa, R.; García Martínez, A.; Arthozoul ., SJL. (2011). The role of in-cylinder gas density and oxygen concentration on late spray mixing and soot oxidation processes. Energy. 36:1599-1611. doi:10.1016/j.energy.2010.12.071S159916113

The role of the in-cylinder gas temperature and oxygen concentration over low load reactivity controlled compression ignition combustion efficiency

Several studies carried out with the aim of improving the RCCI (reactivity controlled compression ignition) concept in terms of thermal efficiency conclude that the main cause of the reduced efficiency at light loads is the reduced combustion efficiency. The present study used both a 3D computational model and engine experiments to explore the effect of the oxygen concentration and intake temperature on RCCI combustion efficiency at light load. The experiments were conducted using a single-cylinder heavy-duty research diesel engine adapted for dual fuel operation. Results suggest that it is possible to achieve an improvement of around 1.5% in the combustion efficiency with both strategies studied; the combined effect of intake temperature and in-cylinder fuel blending as well as the combined effect of oxygen concentration and in-cylinder fuel blending (ICFB). In addition, the direct comparison of both strategies suggests that the combustion losses trend is mainly associated to the in-cylinder equivalence ratio stratification, which is determined by the diesel to gasoline ratio in the blend since the injection timing is kept constant for all the tests. Moreover, the combined effect of the intake temperature and ICFB promotes a slight improvement in the combustion losses over the combined effect of the oxygen concentration and ICFB. (C) 2014 Elsevier Ltd. All rights reserved.The authors gratefully acknowledge the modeling support and guidance of Jose Manuel Pastor and VOLVO Group Trucks Technology (CN-2012-46) for supporting this research.Desantes Fernández, JM.; Benajes Calvo, JV.; García Martínez, A.; Monsalve Serrano, J. (2014). The role of the in-cylinder gas temperature and oxygen concentration over low load reactivity controlled compression ignition combustion efficiency. Energy. 78:854-868. https://doi.org/10.1016/j.energy.2014.10.080S8548687

Effects of piston bowl geometry on Reactivity Controlled Compression Ignition heat transfer and combustion losses at different engine loads

This work investigates the effects of the piston bowl geometry on RCCI (Reactivity Controlled Compression Ignition) heat transfer and combustion losses and its repercussion on the engine efficiency. For this purpose, three piston geometries with compression ratio 14.4:1 have been studied and compared by means of computational modeling. In addition, the engine operating conditions proposed at low, medium and high load were also validated experimentally in a heavy-duty single-cylinder engine adapted for dual fuel operation. The engine speed was kept constant at 1200 rev/min during the research. Results suggest that heat flux through the piston surface represent the major portion of the heat transfer energy. Thus, the comparison of the three geometries demonstrates that reduced piston surface area and reduced charge motion, are the key factors to improve the gross indicated efficiency over the different engine loads. Moreover, it is found that a shallow piston geometry with a smooth transition from the center to the squish region, with a 16% reduced surface area, strongly improves the gross work at low load. However, this gain diminishes due to increased combustion losses as engine load increases. Finally, an intermediate geometry was confirmed as the best balanced piston geometry for RCCI operation over the three different loads.The authors would like to acknowledge VOLVO Group Trucks Technology for supporting this research and to express their gratitude to CONVERGENT SCIENCE Inc. for their kind support for performing the CFD calculations using CONVERGE software.Benajes Calvo, JV.; García Martínez, A.; Pastor Enguídanos, JM.; Monsalve Serrano, J. (2016). Effects of piston bowl geometry on Reactivity Controlled Compression Ignition heat transfer and combustion losses at different engine loads. Energy. 98:64-77. doi:10.1016/j.energy.2016.01.014S64779

Analysis of combustion concepts in a newly designed two-stroke high-speed direct injection compression ignition engine

[EN] Two research paths are being followed to develop compression ignition engines, the extreme optimization of the conventional diesel combustion concept and the development of alternative combustion concepts. The optimization of the conventional diesel combustion concept focuses on controlling the combustion development in an attempt to improve pollutant emissions and efficiency. Additionally, extensive research in four-stroke engines already demonstrated the benefits of the partially premixed combustion concept in terms of emissions and efficiency when using high volatility and low reactivity fuels, such as gasoline-like fuels, from medium-to-high engine loads. A detailed optimization of the conventional diesel combustion concept has been performed in an innovative two-stroke poppet valves high speed direct injection compression ignition engine, in order to find the real limits of this engine configuration. Later, its compatibility with the partially premixed combustion concept using a high octane fuel (Research Octane Number 95) with a triple injection strategy for reducing pollutant emissions at medium-to-low load conditions has been evaluated considering also the impact on engine efficiency. Results confirm the potential for attaining state-of-the-art emission levels operating with diesel combustion, and how emissions and efficiency can be optimized by adjusting the air management settings without facing any additional trade-off aside from that usual between NOX and soot. The feasibility of combining this engine configuration with the gasoline partially premixed combustion concept for controlling pollutant emissions has been also corroborated and, with a fine tuned triple injection strategy, engine efficiency even improves compared to that obtained operating with well-optimized diesel combustion.This research has been partially sponsored by the European Union in framework of the POWERFUL project, FP7/2007-2013, theme 7, sustainable surface transport, grant agreement no. SCP8-GA-2009-234032.Benajes Calvo, JV.; Novella Rosa, R.; De Lima Moradell, DA.; Tribotté, P. (2015). Analysis of combustion concepts in a newly designed two-stroke high-speed direct injection compression ignition engine. International Journal of Engine Research. 16(1):52-67. https://doi.org/10.1177/1468087414562867S5267161Tribotte, P., Ravet, F., Dugue, V., Obernesser, P., Quechon, N., Benajes, J., … De Lima, D. (2012). Two Strokes Diesel Engine - Promising Solution to Reduce CO2 Emissions. Procedia - Social and Behavioral Sciences, 48, 2295-2314. doi:10.1016/j.sbspro.2012.06.1202Wang, X., Huang, Z., Zhang, W., Kuti, O. A., & Nishida, K. (2011). Effects of ultra-high injection pressure and micro-hole nozzle on flame structure and soot formation of impinging diesel spray. Applied Energy, 88(5), 1620-1628. doi:10.1016/j.apenergy.2010.11.035Payri, R., Gimeno, J., Viera, J. P., & Plazas, A. H. (2013). Needle lift profile influence on the vapor phase penetration for a prototype diesel direct acting piezoelectric injector. Fuel, 113, 257-265. doi:10.1016/j.fuel.2013.05.057Macian, V., Payri, R., Ruiz, S., Bardi, M., & Plazas, A. H. (2014). Experimental study of the relationship between injection rate shape and Diesel ignition using a novel piezo-actuated direct-acting injector. Applied Energy, 118, 100-113. doi:10.1016/j.apenergy.2013.12.025Manente, V., Johansson, B., Tunestal, P., & Cannella, W. (2009). Effects of Different Type of Gasoline Fuels on Heavy Duty Partially Premixed Combustion. SAE International Journal of Engines, 2(2), 71-88. doi:10.4271/2009-01-2668Kaiadi, M., Johansson, B., Lundgren, M., & Gaynor, J. A. (2013). Sensitivity Analysis Study on Ethanol Partially Premixed Combustion. SAE International Journal of Engines, 6(1), 120-131. doi:10.4271/2013-01-0269Sellnau, M. C., Sinnamon, J., Hoyer, K., & Husted, H. (2012). Full-Time Gasoline Direct-Injection Compression Ignition (GDCI) for High Efficiency and Low NOx and PM. SAE International Journal of Engines, 5(2), 300-314. doi:10.4271/2012-01-0384Benajes, J., Novella, R., De Lima, D., Tribotté, P., Quechon, N., Obernesser, P., & Dugue, V. (2013). Analysis of the combustion process, pollutant emissions and efficiency of an innovative 2-stroke HSDI engine designed for automotive applications. Applied Thermal Engineering, 58(1-2), 181-193. doi:10.1016/j.applthermaleng.2013.03.050Benajes, J., Molina, S., Novella, R., & De Lima, D. (2014). Implementation of the Partially Premixed Combustion concept in a 2-stroke HSDI diesel engine fueled with gasoline. Applied Energy, 122, 94-111. doi:10.1016/j.apenergy.2014.02.013Payri, R., Salvador, F. J., Gimeno, J., & Novella, R. (2011). Flow regime effects on non-cavitating injection nozzles over spray behavior. International Journal of Heat and Fluid Flow, 32(1), 273-284. doi:10.1016/j.ijheatfluidflow.2010.10.001Payri, R., Salvador, F. J., Gimeno, J., & Bracho, G. (2008). A NEW METHODOLOGY FOR CORRECTING THE SIGNAL CUMULATIVE PHENOMENON ON INJECTION RATE MEASUREMENTS. Experimental Techniques, 32(1), 46-49. doi:10.1111/j.1747-1567.2007.00188.xPAYRI, R., GARCIA, J., SALVADOR, F., & GIMENO, J. (2005). Using spray momentum flux measurements to understand the influence of diesel nozzle geometry on spray characteristics. Fuel, 84(5), 551-561. doi:10.1016/j.fuel.2004.10.009Payri, R., García, A., Domenech, V., Durrett, R., & Plazas, A. H. (2012). An experimental study of gasoline effects on injection rate, momentum flux and spray characteristics using a common rail diesel injection system. Fuel, 97, 390-399. doi:10.1016/j.fuel.2011.11.065Payri, F., Molina, S., Martín, J., & Armas, O. (2006). Influence of measurement errors and estimated parameters on combustion diagnosis. Applied Thermal Engineering, 26(2-3), 226-236. doi:10.1016/j.applthermaleng.2005.05.006Lapuerta, M., Armas, O., & Hernández, J. J. (1999). Diagnosis of DI Diesel combustion from in-cylinder pressure signal by estimation of mean thermodynamic properties of the gas. Applied Thermal Engineering, 19(5), 513-529. doi:10.1016/s1359-4311(98)00075-1Tree, D. R., & Svensson, K. I. (2007). Soot processes in compression ignition engines. Progress in Energy and Combustion Science, 33(3), 272-309. doi:10.1016/j.pecs.2006.03.002Benajes, J., Novella, R., García, A., & Arthozoul, S. (2011). The role of in-cylinder gas density and oxygen concentration on late spray mixing and soot oxidation processes. Energy, 36(3), 1599-1611. doi:10.1016/j.energy.2010.12.071Benajes, J., García-Oliver, J. M., Novella, R., & Kolodziej, C. (2012). Increased particle emissions from early fuel injection timing Diesel low temperature combustion. Fuel, 94, 184-190. doi:10.1016/j.fuel.2011.09.014Arrègle, J., López, J. J., Garcı́a, J. M., & Fenollosa, C. (2003). Development of a zero-dimensional Diesel combustion model. Part 1: Analysis of the quasi-steady diffusion combustion phase. Applied Thermal Engineering, 23(11), 1301-1317. doi:10.1016/s1359-4311(03)00079-6Musculus, M. P. B., Miles, P. C., & Pickett, L. M. (2013). Conceptual models for partially premixed low-temperature diesel combustion. Progress in Energy and Combustion Science, 39(2-3), 246-283. doi:10.1016/j.pecs.2012.09.00

An assessment of the dual-mode reactivity controlled compression ignition/conventional diesel combustion capabilities in a EURO VI medium-duty diesel engine fueled with an intermediate ethanol-gasoline blend and biodiesel

This work investigates the capabilities of the dual-mode reactivity controlled compression ignition/conventional diesel combustion engine operation to cover the full operating range of a EURO VI medium-duty diesel engine with compression ratio of 17.5:1. This concept is based on covering all the engine map switching between the reactivity controlled compression ignition and the conventional diesel, combustion operating modes. Specifically, the benefits of reactivity controlled compression ignition combustion are exploited whenever possible according to certain restrictions, while the conventional diesel combustion operation is used to cover the zones of the engine map in which the reactivity controlled compression ignition operation is limited. The experiments were conducted using a single-cylinder research diesel engine derived from the multi-cylinder production engine. In addition, considering the mandatory presence of biofuels in the future context of road transport and the ability of ethanol to be blended with gasoline, the low reactivity fuel used in the study is a blend of 20% ethanol by volume with 80% of 95 octane number gasoline. Moreover, a diesel containing 7% of biodiesel has been used as high reactivity fuel. Firstly, a reactivity controlled compression ignition mapping is performed to check the operational limits of the concept in this engine platform. Later, based on the results, the potential of the dual-mode concept is discussed. Results suggest that, under the constraints imposed, reactivity controlled compression ignition combustion can be utilized between 25% and 35% load. In this region of the map, reactivity controlled compression ignition can provide up to 2% increased gross indicated efficiency than conventional diesel combustion, but led to lower efficiency at low engine speeds. In addition, it was demonstrated that the regeneration periods of the diesel particulate filter during dual-mode operation can be reduced more than twice, which entails a great reduction of the diesel fuel amount injected in the exhaust line.The authors acknowledge VOLVO Group Trucks Technology for supporting this research. The author J. Monsalve-Serrano thanks the Universitat Politecnica de Valencia for his predoctoral contract (FPI-S2-2015-1531), which is included within the framework of Programa de Apoyo para la Investigacitin y Desarrollo (PAID). Additionally, the authors also wish to thank Gabriel Alcantarilla from CMT - Motores Termicos for his technical work in adapting the test cell.Benajes Calvo, JV.; García Martínez, A.; Monsalve Serrano, J.; Balloul, I.; Pradel, G. (2016). An assessment of the dual-mode reactivity controlled compression ignition/conventional diesel combustion capabilities in a EURO VI medium-duty diesel engine fueled with an intermediate ethanol-gasoline blend and biodiesel. Energy Conversion and Management. 123:381-391. doi:10.1016/j.enconman.2016.06.059S38139112

Investigation on Multiple Injection Strategies for Gasoline PPC Operation in a Newly Designed 2-Stroke HSDI Compression Ignition Engine

Partially Premixed Combustion (PPC) of fuels in the gasoline octane range has proven its potential to achieve simultaneous reduction in soot and NOX emissions, combined with high indicated efficiencies; while still retaining proper control over combustion phasing with the injection event, contrary to fully premixed strategies. However, gasoline fuels with high octane number as the commonly available for the public provide a challenge to ensure reliable ignition especially in the low load range, while fuel blends with lower octane numbers present problems for extending the ignition delay in the high load range and avoid the onset of knocking-like combustion. Thus, choosing an appropriate fuel and injection strategy is critical to solve these issues, assuring successful PPC operation in the full engine map. In this framework, the objective of the present investigation consists of evaluating the use of multiple injection strategies for achieving stable PPC operation, attaining low NOX and soot emissions together with high efficiencies. This research was carried out in a single-cylinder DOHC 2-stroke HSDI CI engine using 95 Research Octane Number (RON) gasoline fuel. Three different operating conditions in terms of indicated mean effective pressure (IMEP) and speed were investigated: 3.1 bar IMEP and 1250 rpm, 5.5 bar IMEP and 1500 rpm and 10.4 bar IMEP and 1500 rpm. Parametric variations of injection timings, at different rail pressures and different fuel split between injections were experimentally performed to analyze the effect of the injection strategy over the combustion process, exhaust emissions and efficiency levels. Experimental results confirm how using an appropriate injection strategy helps to achieve stable PPC operation in the selected operating conditions; with competitive combustion stability, lower NOX and soot levels, and moderate CO and HC emissions with combustion efficiency over 96%, compared to Conventional Diesel Combustion (CDC). Finally, a detailed analysis of the local cylinder conditions was performed by means of 3D-CFD simulations in order to provide guidelines for further optimization of the gasoline PPC concept, when using multiple injection strategies in the 2-stroke engine under development.Benajes Calvo, JV.; Novella Rosa, R.; De Lima Moradell, DA.; Tribotte, P. (2015). Investigation on Multiple Injection Strategies for Gasoline PPC Operation in a Newly Designed 2-Stroke HSDI Compression Ignition Engine. SAE International Journal of Engines. 8(2):758-774. doi:10.4271/2015-01-0830S7587748

Understanding the performance of the multiple injection gasoline partially premixed combustion concept implemented in a 2-Stroke high speed direct injection compression ignition engine

The newly designed Partially Premixed Combustion (PPC) concept operating with high octane fuels like gasoline has confirmed the possibility to combine low NOx and soot emissions keeping high indicated efficiencies, while offering a control over combustion profile and phasing through the injection settings. The potential of this PPC concept regarding pollutant control was experimentally evaluated using a commercial gasoline with Research Octane Number (RON) of 95 in a newly-designed 2-Stroke poppet valves Compression Ignition (Cl) engine for automotive applications. Previous experimental results confirmed how the wide control of the cylinder gas temperature provided by the air management settings brings the possibility to achieve stable gasoline PPC combustion at low and medium speed conditions (1250-2000 rpm) for the whole load range (3.1-10.4 bar IMEP) with good combustion stability (Coefficient of Variation (Coy) of IMEP below 3%), high combustiOn efficiency (over 97%), and low NOx/soot levels. In this context, present research focuses on the two main specific drawbacks of this concept. Firstly, the high Brake Specific Fuel Consumption (BSFC) due to the work required by the mechanical supercharger since the turbocharging system does not provide the suitable pressure ratio at low speeds. Secondly, the high level of noise generated by the combustion process, especially at high loads. Therefore, a dedicated analysis has been carried out to fully exploit the benefits of the gasoline PPC concept combined with the innovative 2-Stroke engine architecture with the aim of identify and break the most relevant trade-offs.The authors kindly recognize the technical support provided by Mr. Pascal Tribotte from RENAULT SAS in the frame of the DREAM-DELTA-68530-13-3205 Project.Benajes Calvo, JV.; Martín Díaz, J.; Novella Rosa, R.; Thein, KJL. (2016). Understanding the performance of the multiple injection gasoline partially premixed combustion concept implemented in a 2-Stroke high speed direct injection compression ignition engine. Applied Energy. 161:465-475. doi:10.1016/j.apenergy.2015.10.034S46547516

A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling

Combustion diagnosis based on in-cylinder pressure signals as well as 0D thermodynamic modelling, are widely used to study and optimize the combustion in reciprocating engines. Both approaches share some uncertainties regarding the sub-models and the experimental installation that, for the sake of accuracy, must be reduced as much as possible in order to obtain reliable results. A methodology, based on the sensitivity effect of such uncertainties on heat release and simulated pressure, is proposed to adjust their values. The methodology is capable of identifying the separate influence of each parameter and to provide a set of values thanks to the Multi-Variable linear regression (MLR) in motoring conditions. The method is flexible enough to deal with different number of uncertainties and can be applied to different engines and thermodynamic models. The final results of the adjustment are validated in combustion conditions, showing an improvement of the apparent combustion efficiency of about 7% with respect to the reference values.The support of the Generalitat Valenciana (BEST/2010/145) is greatly acknowledged.Benajes Calvo, JV.; Olmeda González, PC.; Martín Díaz, J.; Carreño Arango, R. (2014). A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling. Applied Thermal Engineering. 71(1):389-399. https://doi.org/10.1016/j.applthermaleng.2014.07.010S38939971