Download or read book Knock limited Performance of Ethanol Blends in a Spark ignition Engine written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was performed to determine the effect of varying percentages of ethanol in fuel using a CFR engine operated at knock-limited compression ratio and maximum power spark timing. Blends of 85 octane primary reference fuel and ethanol in concentrations between 10 and 25% by volume were tested for performance, fuel economy, and exhaust emissions. The results indicated that when the engine was operated at knock-limited conditions at a constant equivalence ratio, the use of ethanol resulted in a reduction in petroleum fuel usage of 10% greater than the volumetric percentage of the ethanol used in the blend. These results were independent of the amount of ethanol used in the blend. Under these conditions, as the ethanol concentration was increased, BMEP and BSHC increased, BSNO and BSCO remained essentially constant, and exhaust temperature decreased.

Download or read book The Knock limited Performance of Gasoline alcohol water Fuel Blends in a Spark Ignition Engine written by Walter R. McIlveen and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Knock Limited Compression Ratio of Ethanol Gasoline Blends written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethanol offers significant potential for increasing the compression ratio of SI engines resulting from its high octane number and high latent heat of vaporization. A study was conducted to determine the knock limited compression ratio of ethanol gasoline blends to identify the potential for improved operating efficiency. To operate an SI engine in a flex fuel vehicle requires operating strategies that allow operation on a broad range of fuels from gasoline to E85. Since gasoline or low ethanol blend operation is inherently limited by knock at high loads, strategies must be identified which allow operation on these fuels with minimal fuel economy or power density tradeoffs. A single cylinder direct injection spark ignited engine with fully variable hydraulic valve actuation (HVA) is operated at WOT conditions to determine the knock limited compression ratio (CR) of ethanol fuel blends. The geometric compression ratio is varied by changing pistons, producing CR from 9.2 to 13.66. The effective CR is varied using an electro-hydraulic valvetrain that changed the effective trapped displacement using both Early Intake Valve Closing (EIVC) and Late Intake Valve Closing (LIVC). The EIVC and LIVC strategies result in effective CR being reduced while maintaining the geometric expansion ratio. It was found that at substantially similar engine conditions, increasing the ethanol content of the fuel results in higher engine efficiency and higher engine power. These can be partially attributed to a charge cooling effect and a higher heating valve of a stoichiometric mixture for ethanol blends (per unit mass of air). Additional thermodynamic effects on and a mole multiplier are also explored. It was also found that high CR can increase the efficiency of ethanol fuel blends, and as a result, the fuel economy penalty associated with the lower energy content of E85 can be reduced by about a third. Such operation necessitates that the engine be operated in a de-rated manner for gasoline, which is knock-prone at these high CR, in order to maintain compatibility. By using EIVC and LIVC strategies, good efficiency is maintained with gasoline, but power is reduced by about 34%.

Download or read book Performance and Knock Limits of Ethanol written by M. S. Radwan and published by . This book was released on 1985 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion and Performance Characteristics of Methanol Plus Higher Alcohols in a Spark Ignition Engine written by and published by . This book was released on 1987 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Incorporation of Higher Carbon Number Alcohols in Gasoline Blends for Application in Spark Ignition Engines written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties. Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel blends to traditional ethanol blends. Each scenario details an overall objective and identifies chemical and engine-related properties that are crucial to meeting that objective as fuel criteria. Fuel blend property prediction methods are adopted from literature and used to calculate both linear and non-linear properties of multi-component blends. Possible combinations of eight alcohols mixed with a gasoline blendstock are calculated and the properties of the theoretical fuel blends are predicted. Blends that meet all of a scenario's criteria are identified as suitable blends. Blends of higher carbon number alcohols with gasoline blendstock are identified as optimal blends for each scenario if they meet all of the scenario's criteria and maximize either energy content, knock resistance, or petroleum displacement. Optimal blends are tested in a spark-ignition engine. The effect of higher carbon number alcohols as a fuel component on engine performance and emissions is examined. Results suggest that combustion properties of blends of alcohols with carbon numbers from two to six are similar to those of the reference fuel at low and medium engine loads. Properties of blends of alcohols with carbon numbers from two to four are similar to those of the reference fuel even at high loads. However, due to their reduced knock resistance, the suitability of longer chain alcohols, specifically C5 and longer, as blending agents at increased levels is questionable.

Download or read book Knock Limits in Spark Ignited Direct Injected Engines Using Gasoline ethanol Blends written by Emmanuel P. Kasseris and published by . This book was released on 2011 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct Fuel Injection (DI) extends engine knock limits compared to Port Fuel Injection (PFI) by utilizing the in-cylinder charge cooling effect due to fuel evaporation. The use of gasoline/ethanol blends in DI is therefore especially advantageous due to the high heat of vaporization of ethanol. Additionally ethanol blends also display superior chemical resistance to auto-ignition, therefore allowing the further extension of knock limits. An engine with both DI and port fuel injection (PFI) was used to obtain knock onset limits for five gasoline/ethanol blends and different intake air temperatures. Using PFI as a baseline, the amount the intake air needed to be heated in DI to knock at the same conditions as PFI is the effective charge cooling realized and ranges from ~14°C for gasoline to ~49°C for E85. The Livengood-Wu auto-ignition integral in conjunction with the Douad-Eyzat time to auto-ignition correlation was used to predict knock onset. The preexponential factor in the correlation was varied to fit the experimental data. An "Effective Octane Number-ONEFF" is thus obtained for every blend ranging from 97 ONEFF. for gasoline to 115 ONEFF. for E85. ONEFF. captures the chemistry effect on knock and shows that there is little antiknock benefit beyond 30-40% ethanol by volume unless the fuel is used in a DI engine. Using this approach, the anti-knock benefit of charge cooling can also be quantified as an octane number. To achieve that, the ONEFF. calculated for an actual DI operating point including charge cooling effects is compared to the ONEFF. obtained from the auto-ignition integral if the unburned mixture temperature is offset to cancel the charge cooling out. The resulting increase in ONEFF., which can be viewed as an "Evaporative Octane Number" ranges from 5 ONEFF. for gasoline to 18 ONEFF. for E85.

Download or read book Effects of Different Fuels on a Turbocharged Direct Injection Spark Ignition Engine written by Justin E. Negrete and published by . This book was released on 2010 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following pages describe the experimentation and analysis of two different fuels in GM's high compression ratio, turbocharged direct injection (TDI) engine. The focus is on a burn rate analysis for the fuels - gasoline and E85 - at varying intake air temperatures. The results are aimed at aiding in a subsequent study that will look at the benefits of direct injection in turbocharged engines, ethanol's knock suppression properties, and the effects of ethanol concentration in gasoline/ethanol blends. Spark sweeps were performed for each fuel/temperature combination to find the knock limit and to assess each fuels' sensitivity to spark timing and temperature. The findings were that E85 has lower sensitivity to spark timing in terms of NIMEP loss for deviation from MBT timing. A 5% loss in NIMEP was seen at 3° of spark advance or retard for gasoline, whereas E85 took 5' to realize the same drop in NIMEP. Gasoline was also much more sensitive to intake air temperature changes than E85. Increasing the intake air temperature for gasoline decreased the peak pressure, however, knock onset began earlier for the higher temperatures, indicating that end-gas autoignition is more dependent on temperature than pressure. E85's peak pressure sensitivity to spark timing was found to be about 50% lower than that of gasoline and it displayed much higher knock resistance, not knocking until the intake air temperature was 130°C with spark timing of 30° bTDC. These results give some insight into the effectiveness of ethanol to improve gasoline's anti-knock index. Future experiments will aim to quantify charge cooling and anti-knock properties, and determine how ethanol concentration in gasoline/ethanol blends effects this knock suppression ability.

Download or read book SI Combustion written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experiments on the Effects of Dilution and Fuel Composition on Ignition of Gasoline and Alternative Fuels in a Rapid Compression Machine written by Prasanna Chinnathambi and published by . This book was released on 2019 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the first part of this work, ignition of methane-air mixtures under excess air dilution is studied. When excess air is used in SI engine operation, thermal efficiency is increased due to increase in compression ratio together with reduced pumping and heat loses. However, stable operation with excess air is challenging due to poor flammability of the resulting diluted mixture. Hence in order to achieve stable and complete combustion a turbulent jet ignition (TJI) system is used to improve combustion of lean methane-air mixtures. Various nozzle designs and operating strategies for a TJI system were tested in a rapid compression machine. 10-90% burn duration measurements were useful in assessing the performance of the nozzle designs while the 0-10% burn durations indicated if optimal air-fuel ratio is achieved within the pre-chamber at the time of ignition. The results indicated that distributed-jets TJI system offered faster and stable combustion while the concentrated-jets TJI system offered better dilution tolerance.Knock in a SI engine occurs due to autoignition of the end gas mixture and typically occurs in the negative temperature coefficient (NTC) region of the fuel-air mixture. Dilution of intake charge with cold exhaust recirculation gases (EGR) reduces combustion temperatures and decreases mixture reactivity thereby reducing knocking tendency. This enables optimal spark timings to be used, thereby increasing efficiency of SI engines which would otherwise be knock limited. Effect of cold EGR dilution is studied in the RCM by measuring the autoignition delay times of gasoline and gasoline surrogate mixtures diluted with varying levels of CO2. The autoignition experiments in the RCM were performed using a novel direct test chamber (DTC) charge preparation approach. The DTC approach enabled mixture preparation directly within the combustion chamber and eliminated the need for mixing tanks. Effect of CO2 dilution in retarding the autoignition delay times was more pronounced in the NTC region, while it was weaker in the low temperature and high temperature regions. The retarding effect was found to be dependent on both the octane number and the fuel composition of the gasoline being studied.Finally, the effect of substituting ethanol(biofuel) in gasoline surrogates for up to 40% by volume is studied. Ethanol is an octane booster, but it blends antagonistically with aromatics such as toluene and synergistically with alkanes with respect to the resulting octane number of the blends. In order to study this blending effect, two gasoline surrogates containing only alkanes (PRF), and alkanes with large amounts of toluene (TRF) are blended with varying levels of ethanol. The ignition delay times of the resulting mixtures are measured in a rapid compression machine and kinetic analysis was carried out using numerical simulations. The kinetic analysis revealed that ethanol controlled the final stages of ignition for the PRF blends when more than 10% by volume of ethanol is present. However, in the TRF blends, toluene controlled the ignition until mole fractions of ethanol became higher than the toluene indicating the reason for the antagonistic blending nature. It was found that the RON values of the resulting blends matched the trend of the ignition delay times recorded at 740K and 21 bar compressed conditions. This enables qualitative assessment of the RON numbers for new biofuel blends by measuring their ignition delay times in the RCM.

Download or read book Alcohol as an Alternative Fuel for Internal Combustion Engines written by Pravesh Chandra Shukla and published by Springer Nature. This book was released on 2021-05-15 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: div="" This book covers different aspects related to utilization of alcohol fuels in internal combustion (IC) engines with a focus on combustion, performance and emission investigations. The focal point of this book is to present engine combustion, performance and emission characteristics of IC engines fueled by alcohol blended fuels such as methanol, ethanol and butanol. The contents also highlight the importance of alcohol fuel for reducing emission levels. Possibility of alcohol fuels for marine applications has also been discussed. This book is a useful guide for researchers, academics and scientists. ^

Download or read book Influence of Water and Ethanol on Spark Ignition Engine Combustion Performance and Knock Characteristics written by Hong Fu Sing and published by . This book was released on 1983 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion Performance and Emissions Characteristics of a Spark ignition Engine Fueled with Isopropanol n butanol ethanol and Gasoline Blends written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Ethanol in Spark Ignition Engine Fuel Consumption written by Mohamad Waspi Kassim Krismaran and published by . This book was released on 2009 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethanol fuel is known as Gasohol blend, where there is E5, E85, E100 and etcetera. The figure shows percent of ethanol blend in gasoline. Main function of using gasohol is as alternative fuel. This blend can reduce reliability on gasoline. Using gasohol as fuel will affect engine performance, fuel consumption and emission. Ethanol in gasohol increases the octane number of the fuel, higher octane number fuel allow higher compression ratio in engine. For normal naturally-aspirated engine the common compression ratio is 10:1, but gasohol allow compression ratio up to 15:1. Higher compression ratio leads to better combustion and emissions. Experimentally, gasohol will cause increase in fuel consumptions but reduce in engine power and torque. For this project the engine used is Mitsubishi 4G92, four cylinder, water cooled, four-stroke, and 1.6L. The engine designed virtually in GT-Power software and all engine parameters remain constant. By using GT-Power simulation, brake fuel consumption of naturallyaspirated engine is tested using gasoline and gasohol as fuels. The fuel consumption of the engine was tested different rpm for both gasoline and gasohol. The result of the experiment is important to improve engine fuel consumptions which using gasohol as fuel and give advantages to gasohol engine designer to build reliable engine.

Download or read book Effect of CNG and Ethanol Blend on CI Engine Performance written by M. Pani Sharanappa and published by LAP Lambert Academic Publishing. This book was released on 2013-01 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book the effort has been done to find the optimal performance and emission characteristics of compression ignition engine.The performance parameters like thermal efficiency, fuel consumption, heat release rate and peak cylinder pressure are analyzed thoroughly. the emissions like carbon monoxide, carbon dioxide, hydrocarbon and smoke are also investigated thoroughly. CNG is a clean and complete burning fuel and Ethanol is a bio fuel, so the blends of both fuels are advised to use in CI engine.Experimentally it is analyzed that the overall performance is increased significantly and harmful and hazardous particles like carbon dioxide, carbon monoxide reduced drastically.Hence it is advisable that CNG and Ethanol blended fuel is the best one for Compressed ignition eng

Download or read book An Overview of the Effects of Ethanol Gasoline Blends on SI Engine Performance Fuel Efficiency and Emissions written by Robert A. Stein and published by . This book was released on 2013 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: