Dual-fuel Strategy Research Articles

Enhancing engine performance, combustion, and emissions characteristics through CeO2-modified cottonseed biodiesel with hydrogen enrichment: A comprehensive investigation

This investigation delves into the combined use of nanoparticles added biodiesel blends and hydrogen as secondary fuels in CI engines, intending to minimize the reliance on traditional fossil fuels. Calcined wood ash (CWA) has been used as a heterogeneous catalyst for the preparation of cottonseed biodiesel. XRD, SEM and BET analysis was performed to characterize the catalyst. This study evaluates the impact of adding hydrogen and Cerium oxide (CeO2) nanoparticles to cottonseed biodiesel on a CRDI engine. It showed that H2 at an intake rate of 10 L/min improved the engine's overall performance and reduced hazardous emissions. By incorporating the CeO2 nanoparticles (75 ppm) in a cottonseed biodiesel blend and injecting H2 in the engine the BTE was enhanced by 27.8% and BSFC was decreased by 4.41%. There was a reduction of 24%, 22.8%, 6.42%, and 69.5% for HC, CO, CO2 and smoke emissions. On the other hand, NOx rose by 9.3% compared to diesel. The combustion characteristics, such as cylinder pressure showed 26.5% improvement at full load on inclusion of H2. Additionally, under maximum load, the blend C20 + CeO2+H2 has the shortest ignition delay and combustion duration leading to higher engine efficiency. The results of this investigation offer valuable insights into the potential of biodiesel-hydrogen dual-fuel strategies to reduce the environmental impact of CI engines while promoting sustainable energy practices.

Numerical Simulation Research on Combustion and Emission Characteristics of Diesel/Ammonia Dual-Fuel Low-Speed Marine Engine

Amid increasingly stringent global environmental regulations, marine engines are undergoing an essential transition from conventional fossil fuels to alternative fuels to meet escalating regulatory requirements. This study evaluates the effects of injection pressure, the timing of ammonia injection, and the pre-injection of ammonia on combustion and emissions, aiming to identify optimal operational parameters for low-speed marine engines. A three-dimensional model of a large-bore, low-speed marine engine in a high-pressure diffusion mode was developed based on computational fluid dynamics (CFD). Simulations were conducted under 25%, 50%, 75% and 100% loads with a high ammonia energy substitution rate of 95%. The results indicate that, compared to traditional pure diesel operation, adjusting the injection pressure and the ammonia injection timing, along with employing appropriate pre-injection strategies, significantly enhances in-cylinder pressure and temperature, improves thermal efficiency, and reduces specific fuel consumption. Additionally, the dual-fuel strategy using diesel and ammonia effectively reduces nitrogen oxide emissions by up to 37.5% and carbon dioxide emissions by 93.7%.

Analysis of Altitude and Ambient Temperature Effects on the Reactivity of Oxidation Catalysts in the Presence of H2

Worldwide emission standards are now required to cover engine operation under extreme ambient conditions, which affect the raw emissions and the efficiency of the exhaust aftertreatment systems. These regulations also target new combustion technologies for decarbonization, such as neat hydrogen (H2) combustion or dual-fuel strategies, which involve a challenge to the analysis of exhaust aftertreatment system requirements and performance. This work addresses the impact of high altitude and low ambient temperature conditions on the reactivity of an oxidation catalyst in the presence of H2. A reaction mechanism is proposed to cover the main conversion paths of CO, HC, and H2, including the formation and consumption of high-energy surface reaction intermediates. The mechanism has been implemented into a faster-than-real-time reduced-order model for multi-layer washcoat honeycomb catalytic converters. The model was utilized to investigate the effect of H2 concentration on the reactivity of CO and HC within the catalyst under various operating and ambient conditions. By applying the model and examining the selectivity towards different reaction pathways in the presence of H2, insights into surface intermediates and reactivity across different cross-sections of the monolith were obtained. This analysis discusses the underlying causes of reactivity changes promoted by H2 and its relative importance as a function of driving boundary conditions.

Effect of ammonia energy ratio and load on combustion and emissions of an ammonia/diesel dual-fuel engine

Ammonia is receiving increasing attention as a zero-carbon fuel. However, it is difficult to use alone because of its high auto-ignition temperature. Therefore, in this paper, the effects of four ammonia energy ratios (15 %, 30 %, 45 %, and 60 %) on the combustion and emission characteristics of the engine at different loads were studied by using the ammonia/diesel dual-fuel strategy. The results indicated that the presence of ammonia lowered the combustion temperature at all loads, thereby lowering the cylinder temperature and cylinder pressure. In addition, the HRR first increased and then decreased as the ignition delay increased with the increase in ammonia energy ratio. In terms of emissions, at 100 % load, the CO2 and NO of the D40A60 were 65.5 % and 88.14 % lower than that of the D100. The decrease in CO2 was due to more carbon-based fuels being replaced by ammonia. The decrease in NO was due to the decomposition of NO by the thermal deNOx reaction resulting from the lower combustion temperature. The emissions of N2O produced by partial ammonia oxidation offset the greenhouse gas emission reduction effect caused by the reduction of carbon dioxide emissions. Further optimization of the engine combustion strategy is still needed in the future.

Novel approach for efficient operation and reduced harmful emissions on a dual-fuel research engine propelled with hydrogen-enriched natural gas and diesel

ABSTRACT The stricter emission norms have created a need to study recent combustion technology in internal combustion engines. Dual-fuel (DF) combustion technology is one of the key techniques to achieve future emission goals. Natural gas is one of the easily available low-reactive fuels worldwide that can be used in the DF combustion strategy. The main problem with using NG in the DF strategy is its lean-burning ability to produce emissions like HC and CO. The combustion losses associated due to crevice losses in the piston geometry are also the reasons for getting degraded engine performance. In the present study, the lean flammability of NG was improved by enriching it with hydrogen. The combustion losses were reduced using modified disc piston geometry with lower crevice volume. The results showed that the thermal efficiency obtained using HENG/diesel DF strategy with disc piston (DF disc) was only less than 0.3%, 0.4%, and 1% for low, mid, and high load conditions compared to conventional compression ignition mode using bowl piston (CI bowl). The change in piston geometry from bowl to disc type using the DF strategy improved the thermal efficiency by about 3.8%, 3.3%, and 2.7% for three load conditions. The NOx and smoke opacity reduction by about 6% to 19% and 40% to 60% in DF disc mode was achieved compared to CI bowl mode.

Influence of fuel injection timing and trade-off study on the RCCI engine characteristics of Jatropha oil-diesel blend under 1-pentanol dual-fuel strategies.

The current study deals with a reactivity-controlled compression ignition (RCCI) engine working with 1-pentanol as the LRF and JOBD as the HRF. The composition of the pilot fuel includes 20% Jatropha oil and 80% diesel, which nearly matches the heating value and cetane index of petroleum diesel. The research focuses on studying the impact of the pilot fuel injection angle on the engine characteristics at full load conditions, and the pilot fuel injection angle varies from 19, 21, 23, 25, to 27° bTDC at a constant injection pressure of 600 bar. The results revealed that increasing the pilot fuel injection angle increased the engine performance with a 13.36% rise in BTE, a reduction in CO emissions by 11.03%, and a decrease in HC emissions by 9.28% at a pilot fuel injection angle of 25° bTDC at 30% pentanol energy share (BD70P30). On the other hand, NOx emissions rise by 11.07%. The results indicate that the performance of the ternary fuelled RCCI engine can be improved by increasing the fuel injection angle of the pilot fuel.

Experimental assessment of performance and emissions for hydrogen-diesel dual fuel operation in a low displacement compression ignition engine

The combustion of pure H2 in engines is still troublesome, needing further research and development. Using H2 and diesel in a dual-fuel compression ignition engine appears as a more feasible approach. Here we report an experimental assessment of performance and emissions for a single-cylinder, four-stroke, air-cooled compression ignition engine operating with neat diesel and H2-diesel dual-fuel. Previous studies typically show the performance and emissions for a specific operation condition (i.e. a fixed engine speed and torque) or a limited operating range. Our experiments covered engine speeds of 3000 and 3600 rpm and torque levels of 3 and 7 Nm. An in-house designed and built alkaline cell generated the H2 used for the partial substitution of diesel. Compared with neat diesel, the results indicate that adding H2 decreased the air-fuel equivalence ratio and the Brake Specific Diesel Fuel Consumption Efficiency by around 14–29 % and 4–31 %. In contrast, adding H2 increased the Brake Fuel Conversion Efficiency by around 3–36 %. In addition, the Brake Thermal Efficiency increased in the presence of H2 in the range of 3–37 % for the lower engine speed and 27–43 % for the higher engine speed compared with neat diesel. The dual-fuel mode resulted in lower CO and CO2 emissions for the same power output. The emissions of hydrocarbons decreased with H2 addition, except for the lower engine speed and the higher torque. However, the dual-fuel operation resulted in higher NOx emissions than neat diesel, with 2–6 % and 19–48 % increments for the lower and higher engine speeds. H2 emerges as a versatile energy carrier with the potential to tackle current energy and emissions challenges; however, the dual-fuel strategy requires careful management of NOx emissions.

New Combustion Modelling Approach for Methane-Hydrogen Fueled Engines Using Machine Learning and Engine Virtualization

The achievement of a carbon-free emissions economy is one of the main goals to reduce climate change and its negative effects. Scientists and technological improvements have followed this trend, improving efficiency, and reducing carbon and other compounds that foment climate change. Since the main contributor of these emissions is transportation, detaching this sector from fossil fuels is a necessary step towards an environmentally friendly future. Therefore, an evaluation of alternative fuels will be needed to find a suitable replacement for traditional fossil-based fuels. In this scenario, hydrogen appears as a possible solution. However, the existence of the drawbacks associated with the application of H2-ICE redirects the solution to dual-fuel strategies, which consist of mixing different fuels, to reduce negative aspects of their separate use while enhancing the benefits. In this work, a new combustion modelling approach based on machine learning (ML) modeling is proposed for predicting the burning rate of different mixtures of methane (CH4) and hydrogen (H2). Laminar flame speed calculations have been performed to train the ML model, finding a faster way to obtain good results in comparison with actual models applied to SI engines in the virtual engine model framework.

Exploring the potential benefits of high-efficiency dual-fuel combustion on a heavy-duty multi-cylinder engine for SuperTruck I

In support of the Daimler SuperTruck I team’s 55% brake thermal efficiency (BTE) pathway goal, researchers at Oak Ridge National Laboratory performed an experimental investigation of the potential efficiency and emissions benefits of dual-fuel advanced combustion approaches on a modified heavy-duty 15-L Detroit™ DD15 engine. For this work, a natural gas port fuel injection system with an independent injection control for each cylinder was added to the DD15 engine. For the dual-fuel strategies investigated, 65%–90% of the total fuel energy was supplied through the added port fuel injection natural gas (NG) fueling system. The remaining fuel energy was supplied by one or more direct injections of diesel fuel using the production high pressure diesel fueling system. The production DD15 air handling system and combustion geometry were unmodified for this study. Efficiency and emissions with dual-fuel strategies including both low temperature combustion (LTC) and non-LTC approaches such as dual fuel direct-injection were investigated along with control authority over combustion phasing. Parametric studies of dual-fuel NG/diesel advanced combustion were conducted in order to experimentally investigate the potential of high-efficiency, dual-fuel combustion strategies to improve BTE in a multi-cylinder engine, understand the potential reductions in engine-out emissions, and characterize the range of combustion phasing controllability. Characterization of mode transitions from mixing-controlled diesel pilot ignition to kinetically controlled ignition is presented. Key findings from this study included a reproducible demonstration of BTE approaching 48% at up to a 13-bar brake mean effective pressure with significant reductions in engine-out NOx and soot emissions. Additional results from investigating load transients in dual-fuel mode and initial characterization of particle size distribution during dual-fuel operation are presented.

Investigations on the Spray-Atomization of Various Fuels for an Outwardly Opening Piezo Injector for the Application to a Pilot Injection Passenger Car Gas Engine

<div class="section abstract"><div class="htmlview paragraph">Pilot injection gas engines are commonly used as large stationary engines. Often, the combustion is implemented as a dual-fuel strategy, which allows both mixed and diesel-only operation, based on a diesel engine architecture. The current research project focuses on the application of pilot injection in an engine based on gasoline components of the passenger car segment, which are more cost-effective than diesel components. The investigated strategy does not aim for a diesel-only combustion, hence only small liquid quantities are used for the main purpose of providing a strong, reliable ignition source for the natural gas charge. This approach is mainly driven to provide a reliable alternative to the high spark ignition energies required for high cylinder charge densities.</div><div class="htmlview paragraph">When using such small liquid quantities, a standard common-rail diesel nozzle will apparently not be ideal regarding some general specifications. Due to this fact, an outwardly opening piezo injector is intended to be used due to its high performance in several aspects. An issue, which is almost unknown in literature, is the atomization behavior for fuel types differing significantly from the viscosity properties of regular gasoline fuel.</div><div class="htmlview paragraph">The aim of this publication is to clarify, whether the outwardly opening piezo injector can produce an atomization quality, which is sufficient to be used as a pilot injection ignition source for natural gas engines. The experimental results were obtained by means of a combined methodology using both Mie-scattering and PDA (Phase Doppler Anemometry) in a constant volume chamber. The injected masses showed a difference of up to 30% for the examined fuels, whereas liquid penetrations displayed a smaller difference. The Sauter Mean Diameters (SMD) for diesel-like fuels were 5…10μm larger compared to operation on gasoline-like fuels. Additionally, the needle motion for given actuation parameters was studied using a laser vibrometer. Influences of rail pressure, injector temperature, actuation time and reproducibility were investigated, showing that the injector has great reproducibility, but on the other hand requires a complex understanding of the actuation strategy in engine operation.</div></div>

Assessment of a complete truck operating under dual-mode dual-fuel combustion in real life applications: Performance and emissions analysis

The dual-mode dual-fuel (DMDF) strategy has been demonstrated to be a potential combustion mode to cover all the engine map with low-to-moderate NOx and soot emissions and high efficiency simultaneously. This can be accomplished by modifying the injection strategy to promote a fully premixed or a dual-fuel diffusive combustion depending on the operating conditions. The main limitation of the DMDF are the high concentrations of unburned hydrocarbons and carbon monoxide coupled with low exhaust temperatures, which can be a challenge for the stock diesel oxidation catalyst (DOC). Moreover, the use of a diffusive combustion combined with high EGR rates to avoid mechanical issues at high load enhances the soot formation, which can compromise the final soot levels in a homologation cycle. To evaluate these aspects, this work studies the performance and emissions of a DMDF truck concept along a WHVC and different in-service conformity cycles through vehicle systems simulations. For both types of cycles, five payloads were tested (0%, 25%, 50%, 75% and 100%) to evaluate the impact of this parameter on the operating points distribution inside the DMDF map. The first results show that the DMDF concept provides engine-out NOx levels below the EUVI regulation at normative payload (50%) with similar fuel consumption than the conventional diesel truck. On the other hand, the engine-out HC and CO emissions exceed their respective limits in all the cases, while the engine-out soot emissions only reach the EUVI levels up to 25% payload. By this reason, the stock DOC and diesel particulate filter from the conventional diesel truck were modelled and fitted to the DMDF truck model. The results evidenced that the use of these two ATS allows to achieve the EUVI limits in terms of tailpipe HC, CO and soot independently on the cycle and payload analyzed. Moreover, considering the tailpipe emissions values achieved with ATS at 50% payload, it can be inferred that both devices could be downsized for the DMDF application as compared to the conventional ATS for diesel applications.

Effects of the three dual-fuel strategies on performance and emissions of a biodiesel engine

Three dual-fuel strategies, i.e. Strategy S (syngas-biodiesel), Strategy U (upgraded syngas-biodiesel), and Strategy D (DME-biodiesel), for utilization of syngas and biodiesel from biomass wastes in internal combustion engines have been proposed in this study. To compare both the combustion and emission performance of the three strategies, an integrated KIVA4-CHEMKIN CFD platform was constructed implementing a newly combined reaction mechanism. Effects of three dual-fuel strategies have been compared against each other in terms of indicated power, NOx and soot emission. At different engine loads, it was found that the indicated power of all strategies increased with the increasing supplement ratio. Strategy S and Strategy U predict higher indicated power than Strategy D at the high engine load, while lower indicated power than Strategy D at the low engine load. As regards to the NOx emission, an increase in the fuel supplement ratio increases the NOx emission (g/kWh) for both Strategy S and Strategy U at high engine loads, while decreases the NOx emission (g/kWh) due to the enhanced indicated power. Strategy D has relatively higher NOx emission (g/kWh) than Strategy S and Strategy U at all loads. With the increase in fuel supplement ratio, the soot emission generally shows a decreasing trend at all engine loads for all strategies, and Strategy D emits less soot than Strategy S and Strategy U in the cases of high fuel supplement ratio (>0.4) for all engine load conditions.

Effects of low-pressure EGR on gaseous emissions and particle size distribution from a dual-mode dual-fuel (DMDF) concept in a medium-duty engine

The application of a low-temperature combustion concept, such as RCCI combustion under real engine operating conditions is extremely complex. However, the implementation of the dual-mode dual-fuel (DMDF) strategy allows operating in low-medium load with the RCCI combustion and in high load with dual-fuel diffusive combustion. This allows taking advantage of the benefits of RCCI combustion as the simultaneous reduction of PM and NOx emissions. However, there are still serious challenges that required to solve, such as the high-pressure rise rate and the excessive CO and HC emissions. In this sense, this work shows how the implementation and an adequate adjustment of the cooled LP-EGR rate significantly minimize these problems and also shows how the LP-EGR has a greater impact on the DMDF than on the CDC concept.This work has been performed in a modern medium-duty diesel engine fueled with standard gasoline and diesel fuels, with which a cooled LP-EGR loop has been coupled. A TSI Scanning Particle Sizer (SMPS 3936L75) was used to measure the particles size distribution and the Horiba MEXA-ONE-D1-EGR gas analyzer system to determine gaseous emissions. A parametric variation of the LP-EGR rate was experimentally performed to analyze the effect over each combustion process that encompasses the DMDF concept (fully premixed RCCI, highly premixed RCCI and dual-fuel diffusion) and its consequent impact on gaseous and particle emissions. In addition, results were compared against the CDC concept to state the benefits of the DMDF concept. Among the different results obtained, it can be highlighted that during the RCCI strategy the increase in LP-EGR rate provided a reduction in NOx emissions. Nonetheless, unlike that fully premixed RCCI in highly premixed RCCI combustion, the PM emissions increased with this increment in the LP-EGR rate, shifting the size distribution of particle toward larger sizes, but decreasing the HC and CO emissions. Finally, with the exception of the high HC and CO emissions in fully premixed RCCI, in all the combustion strategies of the DMDF concept, a reduction of the analyzed pollutants was observed when compared with the CDC mode.

Effects of Injection Timing on Combustion and Emission Performance of Dual-Fuel Diesel Engine under Low to Medium Load Conditions

A throttle can be installed on the intake pipe of a natural gas (NG)/diesel dual-fuel engine to control the excess air ratio of the air-fuel mixture by adjusting the air intake. Building on a previously proposed NG/diesel dual-fuel supply strategy using the adjustment of excess air ratio, this work further studied the effects of different injection timing schemes on output power, fuel efficiency, and pollutant emissions of a dual-fuel engine under low to medium load conditions. In the experiment, the engine was operated at a speed of 1600 r/min, under either low (27.1 N·m) or medium (50.6 N·m) loads, and the NG substitution rate was either 40%, 60%, or 80%. The effect of different injection timing schemes on the combustion performance of the engine under low to medium load conditions was studied based on in-cylinder pressure changes detected by a pressure sensor. Experimental results showed that under medium-speed low-load conditions and a NG substitution rate of 40%, setting the diesel injection timing to 27 °CA BTDC increased the engine output power by 9.03%, reduced the brake specific energy consumption (BSEC) by 13.33%, and effectively reduced CO, CO2, and HC emissions. Under medium-speed medium-load conditions with a NG substitution rate of 80%, setting the diesel injection timing to 25 °CA BTDC increased the engine output power by 14.62%, reduced the BSEC by 11.73%, and significantly reduced CO, CO2, and HC emissions.

Hydrous Ethanol Steam Reforming and Thermochemical Recuperation to Improve Dual-Fuel Diesel Engine Emissions and Efficiency

Dual-fuel strategies can enable replacement of diesel fuel with low reactivity biofuels like hydrous ethanol. Previous work has shown that dual-fuel strategies using port injection of hydrous ethanol can replace up to 60% of diesel fuel on an energy basis. However, they yield negligible benefits in NOX emissions, soot emissions, and brake thermal efficiency (BTE) over conventional single fuel diesel operation. Pretreatment of hydrous ethanol through steam reforming before mixing with intake air offers the potential to both increase BTE and decrease soot and NOX emissions. Steam reforming can upgrade the heating value of the secondary fuel through thermochemical recuperation (TCR) and produces inert gases to act as a diluent similar to exhaust gas recirculation. This study experimentally investigated a novel thermally integrated steam reforming TCR reactor that uses sensible and chemical energy in the exhaust to provide the necessary heat for hydrous ethanol steam reforming. An off-highway diesel engine was operated at three speed and load settings with varying hydrous ethanol flow rates reaching fumigant energy fractions of up to 70%. The engine achieved soot reductions of close to 90% and minor NOX reductions; however, carbon monoxide and unburned hydrocarbon emissions increased. A first law energy balance using the experimental data shows that the developed TCR system effectively upgraded the heating value of the secondary fuel. Overall, hydrous ethanol steam reforming using TCR can lead to 23% increase in fuel heating value at 100% conversion, a limit approached in the conducted experiments.

Application of dual-fuel combustion over the full operating map in a heavy-duty multi-cylinder engine with reduced compression ratio and diesel oxidation catalyst

This research focuses on the potential of the dual-fuel combustion engine fueled with regular gasoline and diesel to meet the Euro V emission standard over the whole operating range with a simple after-treatment system. For this purpose, a mode-switching strategy was investigated in this work. The engine maps of this strategy were obtained using a dedicated experimental procedure on a modified heavy-duty multi-cylinder engine. The switching of dual-fuel modes mainly depended on the engine load. At 25% engine load, fully premixed reactivity controlled compression ignition combustion was applied to achieve high efficiency and low emission combustion. At operating conditions higher than 50% load, homogeneous charge induced ignition combustion with up to three diesel injections (pre-, main and post-injections) was applied. Then, the effects of compression ratio on the dual-fuel combustion over the full operating map were explored and analyzed in detail. It was found that in spite of a slight increase in the fuel consumption, better combustion and emission performance over the whole operating map could be achieved in the dual-fuel combustion with a lower compression ratio. Finally, the effects of diesel oxidation catalyst were also investigated. The exhaust temperatures of this dual-fuel strategy were higher than the diesel oxidation catalyst light-off temperature, ensuring an effective conversion of the total hydrocarbon and carbon monoxide emissions. Furthermore, from the particle number-size distribution analysis, it was found that reactivity controlled compression ignition was dominated by the nucleation mode particles, while homogeneous charge induced ignition was dominated by the accumulation mode particles which tended to increase as the load increased. In addition, with a lower compression ratio of 16:1 and the application of diesel oxidation catalyst, the cycle-averaged regular emissions of the mode-switching combustion strategy could meet the Euro V emission standard simultaneously in the European Stationary Cycle test.

Potential for Reducing Emissions in Reactivity-Controlled Compression Ignition Engines by Fueling Syngas and Diesel

A syngas/diesel dual-fuel reactivity-controlled compression ignition (RCCI) engine was numerically investigated by an improved multidimensional model coupled with a reduced chemical mechanism. In the test RCCI engine, the syngas was premixed with air in the intake manifold, while the diesel was directly injected into the cylinder well before top dead center (TDC). The effect of the syngas composition, the premixed ratio of the syngas, the initial in-cylinder temperature at intake valve closing (IVC), and the hydrogen (H2) proportion in the syngas on the RCCI combustion and emission characteristics were investigated. The results indicate that the utilization of the syngas/diesel dual-fuel strategy in the RCCI engine with lean and premixed combustion is capable of simultaneously reducing the emissions of nitrogen oxides (NOx) and soot. Compared with the gasoline/diesel RCCI combustion, the combustion characteristics of the syngas/diesel RCCI is much more complicated due to the complex composition of syngas,...

Effects of the direct-injected fuel’s physical and chemical properties on dual-fuel combustion

An experimental and computational study was conducted to explore the effects of the physical properties of the high reactivity fuel in a Reactivity Controlled Compression Ignition (RCCI) combustion dual-fuel strategy. The objective is to systematically isolate the effects of the boiling characteristics of the direct injected fuel in dual-fuel combustion strategies with different levels of fuel stratification. In all studies, iso-octane was used as the low reactivity fuel. The effect of high reactivity fuel physical properties was investigated by comparing the results of engine experiments using two fuels with equal cetane numbers (CN), but different boiling characteristics. The two fuels are 1) a certification grade Ultra Low Sulfur Diesel (ULSD) fuel with a cetane number of 45 and 2) a blend of 21% iso-octane and 89% n-heptane with a cetane number of 45. Computational fluid dynamics (CFD) modeling using the KIVA-3v code with a discrete multi-component evaporation model capable of capturing important physical property influences and a multi-fuel chemistry model capable of describing the chemical kinetics of single and multi-component fuels was used to explain the observed differences in the experiments. It was found that the different boiling curves of the two fuels have minimal effect on the combustion phasing at early and late injection timings. Differences in the combustion phasing were explained by differences in the chemical characteristics of each fuel that could not be matched solely by fixing the CN.

Diesel/Methane Dual Fuel Strategy to Improve Environmental Performance of Energy Power Systems

Diesel/Methane Dual Fuel Strategy to Improve Environmental Performance of Energy Power Systems

Diesel/Methane Dual Fuel Strategy to Improve Environmental Performance of Energy Power Systems

Diesel/Methane Dual Fuel Strategy to Improve Environmental Performance of Energy Power Systems