Break Specific Fuel Consumption Research Articles

Analyzing the effect of carbon nanoparticles on the combustion performance and emissions of a DI diesel engine fueled with the diesel-methanol blend

With the energy crisis and worsening environmental pollution, methanol, as a carbon-neutral fuel, has become a research hotspot in the field of internal combustion engines. This study discusses the influence of different kinds (graphite oxide, GO; multilayer graphene, MG; carbon nanotubes, CNT) and concentrations of carbon nanoparticles, which do not introduce any new elements, added to the diesel-methanol blend on combustion performance and exhaust emissions in a direct injection (DI) diesel engine across diverse operating load conditions. The results showed that the nano-fuels with carbon nano-additives had a better combustion process, with higher peak cylinder pressure (Pmax) and peak heat release rate (HRRmax), and lower ignition delay (ID) and combustion duration (CD). Moreover, the presence of carbon nano-additives resulted in an improvement in brake thermal efficiency (BTE) and a decrement in the break-specific fuel consumption (BSFC). The nano-fuels with GO showed the best optimization effect on the combustion process, followed by MG and CNT. As for emission, the nano-fuels had fewer emissions of CO, HC, and smoke opacity. The nano-fuels with CNT achieved the most significant decrease in emissions of CO and HC. While the presence of GO had the best reduction effect in smoke opacity. However, there was a slight increase in NOx emission. The experimental findings demonstrate that the utilization of carbon nanoparticles in nano-fuels can effectively enhance the application of methanol in internal combustion engines.

Utilization of RSM to optimize the performance and emissions of a single cylinder diesel engine using waste hazelnut biodiesel

One of the environmentally friendly, biodegradable, and renewable alternative fuels widely used around the world is biodiesel. Among vegetable oils, hazelnut oil has great importance in biodiesel production due to its high content of oleic acid. For this study, it is aimed to determine the optimum mixing ratio of biodiesel, produced from waste hazelnut oil (WHB). The tests were carried out on a diesel engine operated with WHB/diesel mixtures at different loads. By means of the design of experimental method (DOE), three different fuel ratios (WHB0, WHB15 and WHB30) were defined and tests have been performed. The results obtained from the tests were analyzed using the response surface method (RSM). Engine load and mixing ratio were determined as input factors while CO, NOx, smoke, indicated thermal efficiency (ITE), ignition delay (ID) and break specific fuel consumption (BSFC) were determined as output factors. In the mathematical model created, the R2 values were found to be 0.98, 0.95, 0.91, 0.98, 0.99 and 0.90 respectively. The high R2 values indicated a strong correlation between the optimization outputs and the real experiments. By using these performance and emission parameters, optimization was performed to identify the optimum blend ratio and load. Based on the results, the optimum inputs were determined as 8.46 Nm load and 4.86 % blend ratio. As a result, with the optimized fuel blend, BSFC (8.03 %), ID (3.57 %), and NO (2.87 %) increased while ITE (7.7 %), CO (18.37 %), and smoke (26.15 %) decreased comparing to WHB0. Despite the slight increase in consumption, the results showed that this blend could be used in an environmentally efficient manner, thanks to the reduction in pollutant emissions.

Analysis of lubricating oil degradation and its influence on brake specific fuel consumption of a light-duty compression-ignition engine running a durability cycle on a test stand

The Euro 6 emission standard required compliance with legal exhaust emissions limits for newly registered vehicles and obligates light duty vehicle manufacturers to respect the 160,000 km durability requirements for in-service conformity. Although there is no legal limit set for fuel consumption, manufacturers are obligated to decrease the carbon footprint of vehicle fleets in order to obtain carbon neutral mobility beyond 2035. The aim of this paper is to analyse the impact of various oils’ and viscosity grades’ degradation on the change in break specific fuel consumption (BSFC) measured over a standardized durability test cycle. Each oil candidate underwent 300 h of durability test running performed on a test bed, without any oil changes. The purpose of the laboratory test was to reproduce the worst-case operating conditions and degradation process of the long-life engine oil type that can be experienced during extreme real life driving of a vehicle. In order to define the influence of the engine oil deterioration on the BSFC profile, the engine operation parameters were continually monitored throughout the test run. Additionally, chemical analysis of the oil was performed and the solid deposits formed on the turbocharger’s compressor side were evaluated. The test results revealed differences up to 3.5% in the BSFC values between the oil candidates tested over the durability cycle. The observed BSFC increase was directly related to the decrease in engine efficiency and can cause higher fuel consumption of the engine, which in turn has an adverse effect on environmental protection goals.

Formation of polycyclic aromatic hydrocarbons and regulated emissions from biodiesel and n-butanol blends containing water

To increase the use of biofuels in diesel engines and reduce harmful emissions emitted from diesel fuel, biodiesel and higher alcohols are fuel sources at the forefront of research. The aim of this study is to understand the effect of water-containing n-butanol-biodiesel blends on regulated emissions, emphasizing nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons (PAHs), which are harmful for the environment and engine durability. 10% n-butanol (B90Bu10) and 10% n-butanol-1% water (B89Bu10W1) were blended with 89% waste-oil biodiesel and tested in a diesel engine at four engine loads at a constant engine speed. PAH samples were analyzed using gas chromatography-mass spectrometry (GC-MS). Results showed B100, B90Bu10 and B89Bu10W1 blends increased break specific fuel consumption (BSFC), exhaust gas temperatures (EGT), carbon monoxide (CO) and hydrocarbon (HC) emissions. However, NOx emissions significantly decreased using butanol and butanol-water blends. Compared to diesel, biodiesel and blended fuels significantly reduced total PAHs and PAH toxicity up to 75.0%. However, B89Bu10W1 increased total PAH and PAH toxicity by 35.7%. Overall, the biodiesel-butanol blend, which emits less carcinogenic pollutants and low-cyclic PAHs than water-containing fuel, was found to reduce the risk of wetstacking in diesel engines operating under low loads.

Experimental comparative study on combustion, performance and emissions characteristics of ethanol-gasoline blends in a two stroke uniflow gasoline engine

Ethanol, an alternative fuels based on alcohol for spark ignition engines, can be used by mixing with gasoline at the proper ratios, and which reducing exhaust emissions by an increase in oxygen content. Although there are many studies conducted on the use of ethanol in internal combustion engines, no studies have been conducted on the use of ethanol in two-stroke uniflow gasoline engines so far. In this experimental study, performance, emission and combustion characteristics of ethanol/gasoline blends (range of ethanol 10% v–50% v) were examined in a two-stroke uniflow gasoline engine at 1800 1/min and full load. In cylinder pressures, heat release rates, mass fraction burnt, engine torque, break specific fuel consumptions, delivery ratio, scavenging efficiency, carbon monoxide (CO), hydrocarbon (HC), carbon dioxide (CO2) and nitrogen oxides (NOx) emissions were investigated. The combustion phasing was advanced after adding ethanol due to the higher burning velocity. Delivery ratio and scavenging efficiency have increased due to the faster evaporation of ethanol than gasoline. Break thermal efficiency (BTE) decreased because of the decreased net work, and break specific fuel consumption (BSFC) increased because ethanol had lower heating value (LHV) than gasoline. CO, HC, CO2 and NOx emissions decreased with the increase in the ethanol content in gasoline.

Energy-Saving and Pollution-Reduction Potential Analysis for Diesel Engines Fueled with Fischer-Tropsch Fuel.

Alternative fuels have attracted wide attention owing to the increasing energy consumption and environmental pollution problems, which are caused by the extensive application of diesel engines for various occasions. The Fischer–Tropsch (F–T) diesel synthesized from coal is considered as one kind of ideal alternative fuel for diesel engines; however, its combustion and exhaust emission characteristics are different from those of national diesel owing to its special fuel properties. Therefore, the combustion and emission characteristics of F–T diesel and 0# diesel, which meet the China stage VI were compared in a common rail direct injection (CRDI) diesel engine. Moreover, energy-saving and pollution-reduction potential were analyzed in one CRDI diesel engine fueled with F–T diesel. The results showed that F–T diesel had an earlier ignition point, shorter ignition delay, lower cylinder pressure, and heat release rate compared with those of 0# diesel at the same operating conditions. Meanwhile, the amplitude, oscillation level, and energy of cylinder pressure were decreased to some extent, with the maximum drops of 0.98 bar, 16.4 dB, and 1.01 × 1012 Pa, respectively. Additionally, under external characteristic conditions, maximum break thermal efficiency (BTE) and break-specific fuel consumption (BSFC) of F–T diesel were reduced by 1.1 and 2.1% on average compared with those of 0# diesel. In addition, CO, HC, NOx, and SOOT emissions of F–T diesel were found to be lower than those of 0# diesel, which were decreased by an average of 8, 3.7, 2.1, and 1.3%, respectively.

Analysis of the impact of different nanoparticle metal oxides as fuel additives in compression ignition engine performance

Biodiesel is used as an alternative fuel in combustion engines. It produces lower carbon monoxide, unburned hydrocarbon, and particulate emissions when compared to that neat diesel. This experimental work aims to upgrade the characteristics of gases emitted, performance and combustion of CI engine. The engine model is a HATZ-1B30-2 Gunt, single cylinder, four stroke, direct injection, air cool CI engine. Experiments are done at 2000 rpm constant speed and dissimilar loads using fuel blends. Three different nanoparticles of metal oxides are used as an additive in different blends of fuel with a dose of 50 ppm. Visual solubility tests are performed for the fuels. The newly developed fuel is burned immediately after preparation to avoid phase separation. The B30–50 MgO nanoparticles showed a 19% reduction in BSFC compared to diesel fuel. CO emission is decreased by 28 % when using D100–50 Al2O3 and NOx emission is decreased by 7 % when using B30–MgO. For the blends containing nanoparticle additives, there is an increase in break power (BP), heat release rate (HRR), and cylinder pressure. Also, there is a reduction in break specific fuel consumption (BSFC), and emissions such as nitrogen oxides (NOx) and carbon monoxide (CO) as in comparison with the neat diesel fuel.

Effect of hydrogen addition on performance and emission characteristics of a common-rail CI engine fueled with diesel/waste cooking oil biodiesel blends

In this study, the effect of hydrogen addition to a compression ignition (CI) engine fueled with the diesel fuel-waste cooking oil biodiesel (WCOB) blend (B25) on the engine performance, and exhaust emissions was examined experimentally. In the tests, a four-cylinder, four-stroke, water-cooled, 1.461-L, turbocharged CI engine was used. The engine tests were performed at the fixed engine speed of 1750 rpm and at the diverse engine loads of 40, 60 and 80 Nm. The hydrogen was added to the intake air at the flow rates of 10, 20, 30 and 40 lpm. According to the results obtained, hydrogen had a positive effect on break specific fuel consumption (BSFC) for all test conditions. The increase occurred at the exhaust gas temperatures (EGTs) and cylinder pressures (CPs) with hydrogen addition. The NOx and total hydrocarbon (THC) emissions decreased with the hydrogen addition until 30 lpm at 40 and 60 Nm engine loads. On the other hand, they increased at 80 Nm engine load for all hydrogen additions. While CO2 and O2 emissions decreased with the hydrogen addition, the smoke emissions increased. It was found that the value of 30 lpm was the optimum condition of the hydrogen addition rates.

Evaluation of comparative combustion, performance, and emission of soybean-based alternative biodiesel fuel blends in a CI engine

In this study, engine tests lead the studies on using diesel fuel (ultra-low sulfur diesel fuel, ULSD), soy-based biodiesel and diesel blends. Performance, combustion and exhaust emission values obtained as ULSD and biofuel blends are presented under load of 3.6 kW, 7.2 kW and 10.8 kW and constant engine speed of 1500 rpm in a diesel engine power generator and compared with ULSD. The maximum increment in break specific fuel consumption (BSFC) is observed at 3.6 kW with SOB20 fuel as about 8% compared to ULSD. Although the BSFC of soy-based biodiesel is high on low loads compared to the ULSD, both types of fuel gave almost identical results. The maximum increment of BTE compared to diesel fuel is occurred as 3.1% when the engine fueled with SOB20 fuel at 10.8 kW. All biodiesel blends are almost the same efficiency as diesel however, when the load increased from 3.6 kW to 10.8 kW, the HC values of ULSD, SOB5 and SOB20 are increased by 28%, 26% and 6%, respectively. However, experimental results show that using biodiesel blends partly similar to ULSD operation in diesel engine according to cylinder gas pressure, heat release rate, heat release rate, knock density and AGT.

Experimental Investigation of Diluents Components on Performance and Emissions of a High Compression Ratio Methanol SI Engine

Increasing compression ratio and using lean burn are two effective techniques for improving engine performance. Methanol has a wide range of sources and is a kind of suitable fuel for a high-compression ratio spark-ignition lean burn engine. Lean burn mainly has a dilution effect, thermal effect and chemical effect. To clarify the influences of different effects and provide guidance for improving composition of dilution gases and applications of this technology, this paper chose Ar, N2 and CO2 as diluents. A spark-ignition methanol engine modified from a diesel engine with a compression ratio of 17.5 was used for the experiments. The results obtained by using methanol spark ignition combustion indicated that at engine speed of 1400 rpm and 25% load, NOx dropped by up to 77.5%, 100% and 100% by Ar, CO2 and N2. Gases with higher specific heat ratio and lower heat capacity represented by Ar exhibited the least adverse effect on combustion and showed a downward break-specific fuel consumption (BSFC) trend. Gas with high specific heat capacity represented by CO2 can decrease NOx and total hydro carbons (THC) emissions at the same time, but the BSFC of CO2 showed the worst trend, followed by N2. Gas affecting the combustion process like CO2 had chemical effect.

Experimental investigation on emission reduction in neem oil biodiesel using selective catalytic reduction and catalytic converter techniques.

In the present study, non-edible seed oil namely raw neem oil was converted into biodiesel using transesterification process. In the experimentation, two biodiesel blends were prepared namely B25 (25% neem oil methyl ester with 75% of diesel) and B50 (50% neem oil methyl ester with 50% diesel). Urea-based selective catalytic reduction (SCR) technique with catalytic converter (CC) was fixed in the exhaust tail pipe of the engine for the reduction of engine exhaust emissions. Initially, the engine was operated with diesel as a working fluid and followed by refilling of biodiesel blends B25 and B50 to obtain the baseline readings without SCR and CC. Then, the same procedure was repeated with SCR and CC technique for emission reduction measurement in diesel, B25 and B50 sample. The experimental results revealed that the B25 blend showed higher break thermal efficiency (BTE) and exhaust gas temperature (EGT) with lower break-specific fuel consumption (BSFC) than B50 blend at all loads. On comparing with biodiesel blends, diesel experiences increased BTE of 31.9% with reduced BSFC of 0.29kg/kWh at full load. A notable emission reduction was noticed for all test fuels in SCR and CC setup. At full load, B25 showed lower carbon monoxide (CO) of 0.09% volume, hydrocarbon (HC) of 24ppm, and smoke of 14 HSU and oxides of nitrogen (NOx) of 735ppm than diesel and B50 in SCR and CC setup. On the whole, the engine with SCR and CC setup showed better performance and emission characteristics than standard engine operation.

Experimental study of the effect of gasoline components on fuel economy, combustion and emissions in GDI engine

An experiment was carried out in a gasoline direct injection (GDI) spark ignition engine to research the effect of gasoline components on fuel economy, combustion and emissions. According to the main components of gasoline, isooctane was selected as the base fuel. Short-chain, medium-chain and long-chain alkanes, ethers and aromatics were respectively blended with isooctane for comparison tests. Results show that aromatics benefit fuel economy under all operating conditions. T20 (20% toluene blended with isooctane) shows a comparatively lower break-specific fuel consumption (BSFC) for its lower cyclical variation while its maximum fuel saving ratio (FSR) could reach 5.42%. At light and medium loads of low speeds, short-chain alkanes shows great potential in the improvement of fuel economy. P20 (20% n-pentane blended with isooctane) whose maximum FSR could reach 4.64% presents better performance of fuel consumption under these operating conditions. By contrast, M20 (20% methyl tertiary butyl ether blended with isooctane) presents the higher BSFC for its higher cyclical variation and lower heat value, with the mean FSR being −2.75%. Medium-chain alkanes, long-chain alkanes and oxygenated fuels are conducive to the optimization of combustion process of the engine because they are able to advance combustion phase due to the shorter ignition delay. In conclusion, medium-chain and long-chain alkanes could reduce CO and THC emissions, to some extent. Compared with pure isooctane and T20, lower CO, NOx and THC emissions are observed for M20 and P20.

Power and fuel economy optimizations of gasoline engines using hydraulic variable valve actuation system

The hydraulic variable valve actuation (HVVA) system can provide greater freedoms to the engine valve motions than most of the traditional cam-based valve train systems do. By considering the characteristics of the HVVA system, the strategies of putting its outstanding flexibilities into use for further improving the performances of gasoline engines with respect to power and fuel economy are developed in this research. A new GT-suite HVVA engine model is proposed which is able to realize the interdependencies of the HVVA system and the engine. In addition, the model is calibrated by experimental data and the proposed genetic algorithm (GA) optimization schemes are carried out for optimizing the engine outputs at full engine load and fuel economy at partial engine load. A potential average improvement of 10.4% on the engine outputs at full load over the entire operating speed range of the test engine is noticed from implementing the optimized HVVA valve motions. Moreover, the advanced GA algorithm for fuel economy optimization ensures the GA optimizer could maintain its proper functionality while non-linear constraints are taken into considerations. The late exhaust valve closure (LEVC) and early intake valve closure (EIVC) strategies are adopted at the same time for granting the engine an internal exhaust gas recirculation (IEGR) feature and together evolved into the HVVA strategy for fulfilling the partial engine loads without throttling. By conducting the advanced GA optimizations with the proposed HVVA strategy for partial engine load operations, the resulted break specific fuel consumption (BSFC) of the HVVA engine could be brought down by 13.1% on average with a maximum of 15.8% over its working speed range at the exemplary 7Nm load point comparing to those of the original test engine.

Skip cycle method with a valve-control mechanism for spark ignition engines

The efficiency decrease of spark ignition (SI) engines under part-load conditions is a considerable issue. Changing the effective stroke volume based on the load level is one of the methods using to improve the part-load efficiency. In this study, a novel alternative engine valve control technique in order to perform a cycle without gas exchange (skip cycle), is examined. The goal of skip cycle strategy is to reduce the effective stroke volume of an engine under part load conditions by skipping several of the four stroke cycles by cutting off the fuel injection and simultaneously deactivating the inlet and exhaust valves. To achieve the same power level in the skip cycle, the cylinder pressure level reaches higher values compared to those in a normal four stroke cycle operation, but inherently not higher than the maximum one at full load of normal cycle. According to the experimental results, the break specific fuel consumption (BSFC) was reduced by 14–26% at a 1–3bar break mean effective pressure (BMEP) and a 1200–1800rpm engine speed of skip cycle operation, in comparison to normal engine operation. The significant decrease in the pumping work from the gas exchange is one of the primary factors for an increase in efficiency under part load conditions. As expected, the fuel consumption reduction rate at lower load conditions was higher. These experimental results indicate a promising potential of the skip cycle system for reducing the fuel consumption under part load conditions.

Combustion and emission performance of a split injection diesel engine in a double swirl combustion system

The authors developed and tested a split injection strategy in a double swirl combustion system (DSCS). Different split injection strategies with different ratios of pilot injection fuel to total fuel mass (herein defined as “pilot injection/fuel mass ratios”) and dwell times were compared with an optimized single injection strategy in terms of the break specific fuel consumption (BSFC). The in-cylinder pressure, heat release rate and in-cylinder temperature were analyzed to explore the in-cylinder combustion process. The NOx emission was also measured. With the total fuel mass being 100 mg/cycle and excess air coefficient being 2 at 2100 r/min at a 5% pilot injection/fuel mass ratio and a 10 deg dwell time, the BSFC decreased by 2.7% compared with the single injection strategy. The NOx emission increased from 940 ppm to 1140 ppm. An ‘acceleration effect’ helped the DSCS when dwell time was short. A spray visualization experiment and numerical simulations were carried out to explain these phenomena. It is concluded that the split injection condition with a smaller pilot injection/fuel mass ratio and a shorter dwell time performed better than the single injection condition in terms of the thermo-atmosphere utilization, space utilization and acceleration effect.

Comparative Study of Properties and Engine Performance Using Blend of Palm and Coconut Biodiesel

Now-a-days the demand of alternative fuel is continuously increasing all over the world due to the rapid depletion of fossil fuel and increased global demand. Biodiesel is renewable and sustainable energy source derived from vegetable oils and animal fats which can be the best substitute of fossil fuel. This paper investigates the property of different biodiesel such as palm, coconut and their blends with conventional diesel also analyzed the engine performance like engine break power, speed, break specific fuel consumption (BSFC), torque in diesel engine. In this paper 20% palm biodiesel with diesel (P20), 20% coconut biodiesel with diesel (C20), 30% palm biodiesel with diesel (P30), 30% coconut biodiesel with diesel (C30) and combination of 15% palm biodiesel and 15% of coconut biodiesel with diesel (C15P15) were used for study. Biodiesel was produced by using transesterification process. The density and kinematic viscosity for C15P15 fuel is slightly higher and flash point is slightly lower than diesel fuel as well as others two biodiesel blends whereas pure palm oil biodiesel shows the higher flash point and acid value. Engine performance test was carried out at 75 kg load condition with variable speeds of 1400 rpm to 2000 rpm at an interval of 200 rpm. Engine brake power produced by mixed biodiesel (C15P15) is slightly lower than the fossil diesel but slightly higher than biodiesel (only palm or coconut). Engine torque produce by the mixed biodiesel is almost the same with the fossil diesel but higher than the others biodiesel blends. Engine brake specific fuel consumption of mixed biodiesel is slightly higher than fossil diesel but lower than others existing biodiesel. It can be reported that the fuel C15P15 showed better performance and can be used as fuel alternative to diesel fuel to reduce the greenhouse gas emission and dependency on crude oil.

The Performance of Four Stroke Surface Ignition Ceramic Heater C.I. Engine using Ethanol-Diesel Blend

In this paper an experimental investigation on the performance of four stroke C.I.engine fueled with pure diesel (B0D100E0) and ethanol-diesel blends containing 10%, 20%, 25% and 30% by volume of ethanol (E) are evaluated. Formaldehyde (B) additive is used to solubility of ethanol indiesel that acts as a bridging agent and bonding to produce a homogeneous blend.The tests are carried out on a ceramic heater10KW single cylinder diesel engine under steady state operating conditions on two specified speeds of 1500 rpm and 2000.rpm. The Partially Stabilized Zirconia (PSZ) ceramic heater is used to reduce the emissions from the engine and improve engine output behavior. The relevant parameters such as brake thermal efficiency (BTE), break specific fuel consumption (BSFC) and emissions are calculated for ethanol-diesel blends by B5D85E10, B5D75E20, B5D70E25and B5D65E30. The PSZ ceramic heater is used to reduce the emissions by 38% of NOx, under half load condition for the blends of B5D85E10 gives minimum CO emissions and unburned HC emissions by 7.5ppm from the engine and improve engine output behavior to 1.8%.

Prediction of engine performance and exhaust emissions for gasoline and methanol using artificial neural network

This study investigates the use of ANN (artificial neural networks) modelling to predict BSFC (break specific fuel consumption), exhaust emissions that are CO (carbon monoxide) and HC (unburned hydrocarbon), and AFR (air–fuel ratio) of a spark ignition engine which operates with methanol and gasoline. To obtain training and testing data, a number of experiments were performed with a four-cylinder, four-stroke test engine operated at different engine speeds and torques. The experimental results reveal that the methanol improved the emission characteristics compared with the gasoline. For the ANN modelling, the standard back-propagation algorithm was found to be the optimum choice for training the model. In the building of the network structure, four different learning algorithms were used such as BFGS (Quasi-Newton back propagation), LM (Levenberg–Marquardt learning algorithm). It was found that the ANN model is able to predict the engine performance and exhaust emissions with a correlation coefficient of 0.998621, 0.977654, 0.998382 and 0.996075 for the BSFC, CO, HC and AFR for testing data, respectively. It was obvious that the developed ANN model is fairly powerful for predicting the brake specific fuel consumption and exhaust emissions of internal combustion engines.

Performance and emissions of a Euro5 small diesel engine fuelled with biodiesel

This article describes the effects of using neat biodiesel on a modern small displacement passenger car diesel engine, highlighting the need for a specific adjusted electronic control unit (ECU) calibration for biodiesel. Engine performance were evaluated at full load with a standard ECU calibration as well as with an ECU calibration specifically adjusted for biodiesel; Break Specific Fuel Consumption (BSFC) and exhaust emissions was then evaluated at seven part load operating conditions, representative of the New European Driving Cycle (NEDC). Tests showed that through recalibration it is possible to obtain the same performance measured under diesel operation, with benefits in terms of engine-out emissions, especially as far as smoke emissions are concerned. Moreover, particle number and size distribution at engine outlet were also evaluated at part load operating conditions, showing a significant reduction of particle number and mass with biodiesel.

Performance of a direct diesel engine using aviation fuels blended with biodiesel

In this study, jet fuel (JF) and railroad fuel (D2) with SME blends (5%, 20%, 50%) were used in a four-cylinder, naturally aspirated, direct (DI) diesel engine. The engine was operated under full load and tested at various speeds to determine the engine’s performance and exhaust emission characteristics. The experimental results show that as the SME ratio of the fuels increases, the break specific fuel consumption (BSFC) and exhaust temperature increase; the SME and its blends show a slight drop in engine performance. In this experiment, carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and smoke opacity values were measured for each fuel. The results of the emission tests revealed that the oxygen content of SME provided a significant reduction in CO and smoke opacity emissions. However, when the test engine was fuelled by SME and its blends, NOx emissions increased.