Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 6314
2017-11-05
Technical Paper
2017-32-0017
Yuzuru Sasaki, Nobuhiko Yamaguchi, Akira Arioka, Katsunori Komuro, Dai Kataoka, Shunji Akamatsu
Abstract In recent times, due to the improvement of internal cylinder flow analysis technology with Computational Fluid Dynamics (CFD), the prediction accuracy of fuel consumption and emission has improved. However, small motorcycles often have complex intake ports which restrict the layout of injectors. Therefore optimization of injection spray to achieve high combustion efficiency and less wall wetting is a challenge. In this study, we predicted fuel consumption and emission performance by the simulation result of air fuel distribution and wall wetting amount with an actual motorcycle engine model. We optimized injector nozzle length, spray angle and spray tip penetration. After the optimization, we evaluated the emission performance and fuel consumption with an actual engine. As a result, we were able to confirm the improvement of fuel consumption and emission performance.
2017-11-05
Technical Paper
2017-32-0032
Rizal Mahmud, Seong Bum Kim, Toru Kurisu, Keiya Nishida, Yoichi Ogata, Jun Kanzaki, Tadashi Tadokoro
Heat loss is more critical for the thermal efficiency improvement in small size diesel engines than large-size diesel engines. More than half of total heat energy in the internal-combustion engine is lost by cooling through the cylinder walls to the atmosphere and the exhaust gas. Therefore, the new combustion concept is needed to reduce losses in the cylinder wall. In a Direct Injection (DI) diesel engine, the spray behavior, including spray-wall impingement has an important role in the combustion development to reduce heat loss. The aim of this study is to understand the mechanism of the heat transfer from the spray and flame to the impinging wall. Experiments were performed in a constant volume vessel (CVV) at high pressures and high temperatures. Fuel was injected using a single-hole injector with a 0.133 mm diameter nozzle. Under these conditions, spray evaporates, then burns near the wall. Spray/flame behavior was investigated with a high-speed video camera.
2017-11-05
Technical Paper
2017-32-0046
Tomoyuki Mukayama, Ryota Nishigami, Annisa Bhikuning, Go Asai, Masaki Kuribayashi, Eriko Matsumura, Jiro Senda
The CO2 gas dissolved fuel for the diesel combustion is effective to reduce the NOx emissions to achieve the internal EGR (Exhaust Gas Recirculation) effect by fuel. This method has supplied EGR gas to the fuel side instead of supply EGR gas to the intake gas side. The fuel has followed specific characteristics for the diesel combustion. When the fuel is injected into the chamber in low pressure, this CO2 gas is separated from the fuel spray. The distribution characteristics of the spray are improved and the improvement of the thermal efficiency by reduction heat loss in the combustion chamber wall, and reduce soot emissions by the lean combustion is expected. Furthermore, this CO2 gas decreases the flame temperature. Further, it is anticipated to reduce NOx emissions by the spray internal EGR effect.
2017-11-05
Technical Paper
2017-32-0049
Kohei Hirano, Yuki Chihara
The new titanium fuel tank has been developed to reduce weight of the fuel tank of production motocrossers. While the titanium permits deep drawing to shape a tank by presswork, the processing of titanium material is difficult, hence no past application of the material for a motorcycle fuel tank. This project was aimed at development of new techniques for mass production of titanium fuel tanks, and succeeded in mass production of titanium fuel tanks having an adequate durability to apply to a motocrosser that can receive a strong impact while driving. As a result, approximately 40% of weight reduction from the plastic fuel tank having the same fuel capacity was realized.
2017-11-05
Technical Paper
2017-32-0054
Iman Kartolaksono Reksowardojo, Phonethip Trichanh, Kevin Ferdyamin, Mega Zulfikar Akbar
This research aims to investigate the effect of ethanol blends with pure gasoline to the rate of fuel consumption and emissions of fuel injection motorcycle 115 cc with automatic transmission which is the population is dominant in Indonesia. Variations of the bioethanol mixture are 0%, 5%, 10%, and 20% ethanol. The experiment conducted in two different conditions by using three ways catalytic converter (TWC) in the exhaust pipe and without using TWC in the exhaust pipe. First, all engine setting was originally manufacture setting. Second, the AFR is set in stoichiometry condition (λ = 1) and ignition timing set in MBT timing using modified ECU. The experiment performed on the chassis dynamometer and referred on the standard cycle ECE 15. The results of this experiment showed that increment of ethanol content in the fuel makes the rate of fuel consumption and CO2 emission both increased but CO and HC emissions decreased.
2017-11-05
Technical Paper
2017-32-0059
Yoshinori Nakao, Atsushi Hisano, Masahito Saitou, Kozo Suzuki, Katsumi Sobakiri
In this paper, it is also elucidated that the influence of the downstream injection, which caused different fuel behavior in contrast with upstream injection, on the THC after warm-up and at the maximum power, as well as its mechanism. The mechanism is clarified by use of the intake port visualization system. First, at each injection position, the effect of injection timing on THC emission after warm-up was evaluated. In the downstream injection, THC emission increases during the injection timing, in which the fuel spray directly flows in-cylinder during the intake process (hereinafter defined as the intake valve opening injection timing), and the amount of THC emission is reduced at the other injection timing (hereinafter defined as the intake valve closing injection timing). Based on the results of visualizing the intake port, injected fuel phase near the intake valve is spray in the downstream injection.
2017-11-05
Technical Paper
2017-32-0067
Ranjana Meena, Pradeep Ramachandra, Adwitiya Dube
With the increased demand of mobility in the form of two-wheelers and the continued dominant share of Internal Combustion Engines (ICE) in Indian market, there is considerable influence on the deterioration of air quality. The regulators in this region have legislated Bharat Stage 6 (BS6) as a measure to restrict tail pipe emissions, which necessitates the automotive industry to work towards emission optimization measures. Some of the factors influencing this includes, air-fuel mixture formation, spray targeting, fuel properties, flow dynamics, combustion chemical kinetics, exhaust after-treatment etc. The focus area of this paper is to study the influence of air-fuel mixture formation which is highly dependent on fuel droplet atomization, injection timing, fuel injector, injection pressure and mixture preparation techniques to reduce the engine out emissions.
2017-11-05
Technical Paper
2017-32-0077
Herman Saputro, Laila fitriana, Masato Mikami
Experiments of flame-spread of fuel droplets have been performed in microgravity actively. However, the experiment has limitation in the number of droplets due to relatively short microgravity durations in the ground based facilities. It is difficult to conduct flame spread experiments of large scale droplet clouds in microgravity. This study conducted simulation of flame-spread behavior in randomly distributed large-scale droplet clouds by using a percolation approach, in order to make a theoretical link the gap between droplet combustion experiments and spray combustion phenomenon with considering two-droplet interaction. Droplets are arranged at lattice points in 2D lattice. The occurrence probability of group combustion (OPGC) is calculated as a function of the mean droplet spacing (S/d0)m.
2017-11-05
Technical Paper
2017-32-0115
Tatsuya Kuboyama, Yasuo Moriyoshi, Hidenori Kosaka
To investigate the heat transfer phenomena inside the combustion chamber of a diesel engine, a correlation for the heat transfer coefficient in a combustion chamber of a diesel engine was investigated based on heat flux measured by the authors in the previous study(8) using the rapid compression and expansion machine. In the correlation defined in the present study, thermodynamically estimated two-zone temperatures in the burned zone and the unburned zone are applied. The characteristic velocity given in the correlation is related to the speed of spray flame impinging on the wall during the fuel injection period. After the fuel injection period, the velocity term of the Woschni’s equation is applied. It was shown that the proposed correlation well expresses heat transfer phenomena in diesel engines.
2017-11-05
Technical Paper
2017-32-0096
H. R. Guru Kiran, J. M. Mallikarjuna
Today, homogenous charge compression ignition (HCCI) engines are becoming very popular because of their potential to reduce soot and nitric oxides (NOx) emissions simultaneously. But, their performance and emission characteristics are very much dependent upon fuel injection strategy and parameters. However, they also have many challenges viz., improper combustion phasing, high rate of pressure rise and narrow operating range. Therefore, addressing them is very essential before making them a commercial success. This study focuses on evaluating the effect of fuel injection strategy and parameters on the performance and emission characteristics of a HCCI engine by computational fluid dynamics (CFD) analysis. In this study, a four-stroke engine operating in the HCCI mode is considered and the CFD analysis is carried out by using the CONVERGE.
2017-11-05
Technical Paper
2017-32-0103
T. Painrungrot, C. Charoenphonphanich, H. Kosaka, M. Tongroon
Ethanol is a good choice for alternative fuel which is prefer to dual fuel diesel engine. In this study, ethanol will be injected in to the intake manifold to cool down the intake temperature and reduce the amount of diesel fuel consumption. And also, use a technique called internal exhaust gas recirculation. The exhaust valve will be reopened during the intake stroke for 4mm. to vaporized the injected ethanol in the combustion chamber. The objective of this research is to study the effect of injection timing of dual fuel (diesel) on the engine performance and exhaust emissions of a supercharged, single cylinder 4-stroke direct injection compression ignition engine including ethanol fumigation and internal EGR, and also varying the injection pressure of diesel. Then using ethanol fuel as a secondary fuel to replace the energy input from diesel fuel by 10, 20, and 30%.
2017-11-05
Technical Paper
2017-32-0038
Rose Mary Simon Palackal, Balagovind Nandakumar Kartha, Karthikeyan Ramachandran, Srikanth Vijaykumar, Pramod Reddemreddy
Today, 99% of the two wheelers in India operate with carburetor based fuel delivery system. But with implementation of Bharath Stage VI emission norms, compliance to emission limits along with monitoring of components in the system that contributes towards tail pipe emissions would be challenging. With the introduction of the OBD II (On-Board Diagnostics) and emission durability, mass migration to electronically controlled fuel delivery system is very much expected. The new emission norms also call for precise metering of the injected fuel and therefore demands extended calibration effort. The calibration of engine management system starts with the generation of pre-calibration dataset capable of operating the engine at all operating points followed by base calibration of the main parameters such as air charge estimation, fuel injection quantity, injection timing and ignition angles relative to the piston position.
2017-11-05
Technical Paper
2017-32-0002
N. Balasubramanian, G. R. Keerthi, J. T. Nithin, S. Jayabalan, T. N. C. Anand
This paper presents the results of tests using a prototype pump-integrated port fuel injector that is designed for small gasoline engines. The unique construction of the injector eliminates the need for a separate feed pump. The device is intended as a solution to meet the upcoming emission norms similar to Euro 6 standards, to be implemented in Asian countries. In particular, the Indian two-wheeler market which produces around 20 million vehicles annually [1], migrates to Bharat Stage VI (BS VI) emission standards in the year 2020. This market is largely cost-driven and currently most of the motorcycles use carburettors as fuelling systems. It is expected that the adoption of port fuel injection would be inevitable to meet the BS VI emission norms. To minimize the increase in cost due to such a change, a new injector is developed, which integrates the fuel pump within the injector, making the system simple and compact, while calling for no change in the fuel tank.
2017-11-05
Technical Paper
2017-32-0003
Timothy C. Simmons, Larry J. Markoski
An innovative carburetor system has been developed for use in single cylinder small engines. The carburetor has been implemented on a 79cc 4 stroke portable gasoline generator for the purposes of illustrating its effect in reducing emissions, engine deposits and improving fuel economy without re-jetting the carburetor. This method of carburetion dynamically tunes the venturi effect in the carburetor, allowing for air density, fuel viscosity and fuel type compensation for optimal AFR. Modified and stock generators were tested at various power levels, elevations and temperatures to simulate operational environments. The improvements in emissions and fuel consumption will be presented. In addition, the system has been designed as a bolt-on, low cost alternative to an EFI method of complying with emissions regulations for existing small engine applications.
2017-10-13
Technical Paper
2017-01-5017
Ronith Stanly, Gopakumar Parameswaran, R Rajkiran
Abstract Conventionally, influence of injector coking deposits has been studied using accelerated coking methods. For this work we used in-use vehicles fitted with Common Rail Direct injection (CRDi) injectors in “as-is where is” condition with considerable coked injector deposits. They were then cleaned with a commercial fuel system cleaning solution which did not require the removal of injectors; the influence of injector deposits on vehicular performance and spray field were studied. It was observed that the removal of coking deposits resulted in an increase in the peak power of the vehicle, a lower fuel injected quantity and lower fuel injection duration. It was also observed that the fuel system cleaning procedure resulted in better atomization of fuel spray, better uniformity of the multiple spray jets and an increase in the flow rate of the test injectors.
2017-10-08
Technical Paper
2017-01-2373
Jun Kaniyu, Shogo Sakatani, Eriko Matsumura, Takaaki Kitamura
Abstract Diesel Particulate Filter (DPF) is a very effective aftertreatment device to limit particulate emissions from diesel engines. As the amount of soot collected in the DPF increases, the pressure loss increases. Therefore, DPF regeneration needs to be performed. Injected fuel into the exhaust line upstream of the Diesel Oxidation Catalyst (DOC), hydrocarbons are oxidized on the DOC, which increases the exhaust gas temperature at the DPF inlet. It is also necessary that the injected fuel is completely vaporized before entering the DOC, and uniformly mixed with the exhaust gases in order to make the DOC work efficiency. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line are challenging. Therefore, it is important that the fuel spray feature is grasped to perform DPF regeneration effectively. The purpose of this study is the constructing a simulation model.
2017-10-08
Technical Paper
2017-01-2407
Michael Bardon, Greg Pucher, David Gardiner, Javier Ariztegui, Roger Cracknell, Heather Hamje, Leonardo Pellegrini, David Rickeard
Abstract Low Temperature Combustion using compression ignition may provide high efficiency combined with low emissions of oxides of nitrogen and soot. This process is facilitated by fuels with lower cetane number than standard diesel fuel. Mixtures of gasoline and diesel (“dieseline”) may be one way of achieving this, but a practical concern is the flammability of the headspace vapours in the vehicle fuel tank. Gasoline is much more volatile than diesel so, at most ambient temperatures, the headspace vapours in the tank are too rich to burn. A gasoline/diesel mixture in a fuel tank therefore can result in a flammable headspace, particularly at cold ambient temperatures. A mathematical model is presented that predicts the flammability of the headspace vapours in a tank containing mixtures of gasoline and diesel fuel. Fourteen hydrocarbons and ethanol represent the volatile components. Heavier components are treated as non-volatile diluents in the liquid phase.
2017-10-08
Technical Paper
2017-01-2425
Ramit Verma, Ramdas R Ugale
Abstract On two wheelers, magneto/alternator generates either single/three phase AC power and Regulator Rectifier Unit (RRU) does regulated rectification to charge the battery. In order to face the requirements of 2-wheeler engine with respect to upcoming stringent regulations like electronic fuel injection (EFI), anti-lock braking system (ABS), automatic headlamp on (AHO) in emerging markets like India; vehicles demand more electrical power from batteries. This demands higher power from alternator and consequently from RRU. Requirement of higher output power presents challenges on regulator rectifier unit in terms of size, power dissipation management and reliability. In this paper, improved performance of MOSFET based RRU is discussed in comparison to Silicon Controlled Rectifier (SCR) based RRU. The motivation/benefits of MOSFET based design is described along with the thermal behavior and temperature coefficient performance of RRU with test results.
2017-10-08
Technical Paper
2017-01-2444
Yanzhong Wang, Guanhua Song
Abstract High-speed rotating gears are generally lubricated by spray lubrication. Lubricating oil is driven by high-speed rotating gear, and some lubricating oil will be excited into oil mist, so that the gears are in the gas-liquid mixed environment. In this paper, the computational fluid dynamics model of the spray lubrication cooling process is established based on the gear heat transfer behavior under the spray lubrication condition. The influence of different spray parameters on the liquid-solid two-phase convective heat transfer coefficient is obtained. On this basis, the accurate boundary conditions of gear temperature field calculation are analyzed by studying the heat transfer behavior of high speed gear spray lubrication. The calculation model of gear temperature based on spray lubrication is established, and the temperature field distribution of gear is obtained.
2017-10-08
Technical Paper
2017-01-2198
Zhihong Li, Guoxiu Li, Lan Wang, Hongmeng Li, Jie Wang, Haizhou Guo, Shuangyi He
Abstract The electromagnetic valve driving mechanism is the significant equipment, which plays a vital role in the unit pump injection system; therefore, the performance of the electromagnetic valve directly influences the function of the control system. Based on the operation conditions of the unit pump injection system, a steady electromagnetic valve model was modified to study the influence factors of electromagnetic force and the best combination to get the maximum electromagnetic force. The validation model was verified by experiment. The effects of some crucial parameters upon the electromagnetic force were investigated in the present paper, (including working airspace, magnetic pole’s cross-sectional area, coil position, coil turn, the armature thickness). The results show that the electromagnetic force of the solenoid valve enhanced with the increase of driving current and with the decrease of working airspace.
2017-10-08
Technical Paper
2017-01-2209
Christian Ibron, Mehdi Jangi, Tommaso Lucchini, Xue-Song Bai
Partially premixed combustion (PPC) can be applied to decrease emissions and increase fuel efficiency in direct injection, compression ignition (DICI) combustion engines. PPC is strongly influenced by the mixing of fuel and oxidizer, which for a given fuel is controlled mainly by (a) the fuel injection, (b) the in-cylinder flow, and (c) the geometry and dynamics of the engine. As the injection timings can vary over a wide range in PPC combustion, detailed knowledge of the in-cylinder flow over the whole intake and compression strokes can improve our understanding of PPC combustion. In computational fluid dynamics (CFD) the in-cylinder flow is sometimes simplified and modeled as a solid-body rotation profile at some time prior to injection to produce a realistic flow field at the moment of injection. In real engines, the in-cylinder flow motion is governed by the intake manifold, the valve motion, and the engine geometry.
2017-10-08
Technical Paper
2017-01-2212
Jun Peng, Mingyang Ma, Wang Weizhi, Fu-qiang Bai, Qing Du, F Zhang
Abstract High-pressure common rail (HPCR) fuel injection system is the most widely used fuel system in diesel engines. However, when multiple injection strategy is used, the pressure wave fluctuation is un-avoided due to the opening and closing of the needle valve which will affect the subsequent fuel injection and combustion characteristics. In this paper, several parameters: injection pressure, injection intervals, the main injection pulse widths are investigated on a common rail fuel injection test rig with two injection pulses to explore their effect on the fuel injection rate and fuel quantity. The result showed that the longer injection interval between the pilot and main injections will lead to a rail pressure drop at the beginning of the main injection so that a smaller fuel quantity will be delivered. The main injection pulse width also influences fuel injection rate and the main fuel quantity.
2017-10-08
Technical Paper
2017-01-2217
Fushui Liu, Ning Kang, Yikai Li, Pei Wang
Abstract The electronic unit pump system, which is widely applied to the heavy-duty diesel engine, belongs to the pulsating high-pressure fuel injection system, and the fuel pressure fluctuations have an essential influence on the spray and combustion in the internal combustion engine. Besides, pressure fluctuations are always aroused by the motion of actuators, such as the injector or other control valves, so it is also an advantage for fault diagnosis and feedback control to ascertain the relationship between the pressure fluctuation and the motion of the actuator. In this study, experiments and 1D-simulation were carried on to investigate the fuel pressure fluctuation characteristics and their correlations with the transient motion of the needle valve in the injector.
2017-10-08
Technical Paper
2017-01-2230
Nizar F.O. Al-Muhsen, Guang Hong
Abstract Ethanol as a renewable fuel has been used widely in vehicles. Dual fuel injection is one of the new techniques in development for increasing the engine’s thermal efficiency and reducing the pollutant emissions. This study reports experimental investigation to the dual ethanol fuel injection with a focus on the effect of spark timing on the engine performance at different volumetric ratios of ethanol directly injected to ethanol port injected. Experiments were conducted on a single cylinder 250cc spark ignition engine at two engine loads and 3500 RPM. The spark timing was varied from 15 to 42 CAD bTDC at the light load and from 15 to 32 CAD bTDC at the medium load, while the volumetric ratio of direct injection (DI%) was varied from 0% to 100%.
2017-10-08
Technical Paper
2017-01-2238
Ripudaman Singh, Travis Burch, George Lavoie, Margaret Wooldridge, Mohammad Fatouraie
Abstract Numerous studies have demonstrated the benefits of ethanol in increasing the thermal efficiency of gasoline-fueled spark ignition engines via the higher enthalpy of vaporization and higher knock resistance of ethanol compared with gasoline. This study expands on previous work by considering a split fuel injection strategy with a boosted direct injection spark ignition engine fueled with E0 (100% by volume reference grade gasoline; with research octane number = 91 and motor octane number = 83), E100 (100% by volume anhydrous ethanol), and various splash-blends of the two fuels. Experiments were performed using a production 3-cylinder Ford Ecoboost engine where two cylinders were de-activated to create a single-cylinder engine with a displacement of 0.33 L. The engine was operated over a range of loads with boosted intake manifold absolute pressure (MAP) from 1 bar to 1.5 bar.
2017-10-08
Technical Paper
2017-01-2251
Lei Feng, Beiling Chen, Haifeng Liu, Mingfa Yao, Chao Geng
Abstract The flame structure and combustion characteristics of wall-impinging diesel fuel spray were investigated in a high-temperature high-pressure constant volume combustion vessel. The ambient temperature (Ta) was set to 773 K. The wall temperatures (Tw) were set to 523 K, 673 K and 773 K respectively. Three different injection pressures (Pi) of 600 bar, 1000bar and 1600bar, two ambient pressures (Pa) of 2 MPa and 4 MPa were applied. The flame development process of wall-impinging spray was measured by high-speed photography, which was utilized to quantify the flame luminosity intensity, ignition delay and flame geometrical parameters. The results reveal that, as the wall temperature increases, the flame luminosity intensity increases and the ignition delay decreases.
2017-10-08
Technical Paper
2017-01-2249
Chen Wang, Tianyou Wang, Kai Sun, Zhen Lu, Yong Gui
Abstract Clean combustion is critical for marine engines to meet the Tier III emission regulation. In this paper, the effects of EGR and injection strategies (including injection pressure, injection timing as well as multiple injection technology) on the performance and emissions of a 2-stroke, low speed marine diesel engine were investigated by using computational fluid dynamics (CFD) simulations to reach the IMO Tier III NOx emissions target and reduce the fuel consumption rate. Due to the large length scale of the marine engine, RANS simulation was performed in combination with the CTC-SHELL combustion model. Based on the simulation model, the variation of the cylinder pressure curve, the average temperature in the cylinder, the combustion heat release rate and the emission characteristics were studied.
2017-10-08
Technical Paper
2017-01-2255
Raul Payri, Jaime Gimeno, Santiago Cardona, Sridhar Ayyapureddi
Abstract A prototype multi-hole diesel injector operating with n-heptane fuel from a high-pressure common rail system is used in a high-pressure and high-temperature test rig capable of reaching 1100 Kelvin and 150 bar under different oxygen concentrations. A novel optical set-up capable of visualizing the soot cloud evolution in the fuel jet from 30 to 85 millimeters from the nozzle exit with the high-speed color diffused back illumination technique is used as a result of the insertion of a high-pressure window in the injector holder opposite to the frontal window of the vessel. The experiments performed in this work used one wavelength provide information about physical of the soot properties, experimental results variating the operational conditions show the reduction of soot formation with an increase in injection pressure, a reduction in ambient temperature, a reduction in oxygen concentration or a reduction in ambient density.
2017-10-08
Technical Paper
2017-01-2266
Bin Yang, Hu Wang, Mingfa Yao, Zunqing Zheng, Jialin Liu, Naifeng Ma, Qiping Wang, Haien Zha, Peng Chen
Abstract Gasoline partially premixed combustion shows the potential to achieve clean and high-efficiency combustion. Injection strategies show great influence on in-cylinder air flow and in-cylinder fuel distribution before auto-ignition, which can significantly affect the combustion characteristics and emissions. This study explored the effects of various injection strategies, including port fuel injection (PFI), single direct injection (DIm), double direct injection (DIp+DIm) and port fuel injection coupled with a direct injection (PFI+DIm) on the combustion characteristics and emissions in a modified single cylinder heavy-duty diesel engine fueled with 92# gasoline at low load. The investigation consists of two parts. Firstly, the comparison among PFI, PFI+DIm, and DIp+DIm strategies was conducted at a fixed CA50 to explore the effects of PFI+DIm and DIp+DIm strategies on the thermal efficiency and combustion stability.
2017-10-08
Technical Paper
2017-01-2269
Shijun Dong, Xiaobei Cheng, Biao Ou, Can Yang, Zhaowen Wang, Fumin Pan
Abstract Based on a composed PRF/ethanol/PAH mechanism, simulations were conducted to investigate the combustion characteristics of n-heptane spray under premixed ethanol/air and iso-octane/air atmosphere in a combustion vessel. The effects of premixed ethanol and iso-octane on ignition delay, important soot precursors and soot volume fraction of n-heptane spray were studied. Also, simulated results with and without considering the cooling effects of premixed fuel vaporization were compared. When the cooling effect of premixed fuel vaporization was not considered, simulations showed that premixed ethanol could increase the ignition delay of n-heptane spray at ambient temperatures below 850K. However, premixed iso-octane showed little inhibition effect on ignition of n-heptane spray. Also, it was found that both premixed ethanol and iso-octane contributed to faster ignition under high ambient temperatures.
Viewing 1 to 30 of 6314