Refine Your Search



Search Results

Technical Paper

Simultaneous Measurements of the Components of VOCs and PAHs in Diesel Exhaust Gas using a Laser Ionization Method

A simple real-time measurement system for the components of volatile organic compounds (VOCs) and polyaromatic hydrocarbons (PAHs) in automobile exhaust gas using a laser ionization method was developed. This method was used to detect VOCs and PAHs in the exhaust gas of a diesel truck while idling, at 60 km/h, and in the Japanese driving mode JE05. As a result, various VOCs and PAHs, such as xylene and naphthalene, were simultaneously detected, and real-time changes in their concentration were obtained at 1 s intervals.
Technical Paper

Active Control of Drive Motion of Four Wheel Steering Car with Neural Network

Two kinds of active control systems, using neural networks (NN), are presented for realizing optimal driving motion of four wheel steer (4WS) cars. The first system is based on the assumption that the car is simplified as a linear two wheel bycycle model, and that the friction force between tire and road surface is represented by Fiala's nonlinear model. The nonlinear relation between the slip angle of tire and the cornering force is expressed with NN. A model-following type control strategy is adopted in the first system, with both the feedforward and feedback gains for the control of the rear wheel steering angle adaptively determined with NN according to change of front wheel steering angle. The second system is based on the assumption that both the dynamical characteristics of the car and the tire friction force are nonlinear. The nonlinear dynamical characteristics of the car and the friction force are identified with NN, using the measured data of an actual car.
Technical Paper

Simultaneous Measurements of Temperatures of Flame and Wall Surface in a Combustion Chamber of Diesel Engine

In order to investigate the combustion phenomena in a combustion chamber of the diesel engine at transient operations, the simultaneous measurements of temperatures of flame and wall surface in a combustion chamber were conducted. The new technique for simultaneous measurements of flame temperature and wall surface was developed. Laser-Induced phosphorescence was used for the measurement of wall surface temperature which was coupled with the flame temperature measurement by a two-color pyrometry. The NOx and soot emissions were also measured simultaneously in transient operations. The relation between the temporal changes of emissions and temperatures of flame and surface wall are discussed. The results show that the temporal change of NOx emission during transient operation is similar to that of the average gas temperature in a chamber. On the other hand, the temporal change of soot emission is similar to neither that of flame temperature nor that of average gas temperature.
Journal Article

Particulate Matter Trapping and Oxidation on a Catalyst Membrane

Particulate matter (PM) trapping and oxidation in regeneration on the surface of a diesel particulate catalyst-membrane filter (DPMFs) were investigated in detail using an all-in-focus optical microscope. The DPMF consists of two-layer sintered filters, where a SiC-nanoparticle membrane (made from a mixture of 80 nm and 500 nm powders) covers the surface of a conventional SiC filter. Using a visualization experiment, it was shown that PMs were trapped homogeneously along fine surface pores of the membrane's top surface, whereas in the regeneration process, the particulates in contact with the membrane may have been oxidized with some catalytic effect of the SiC nanoparticles. A soot cake was reacted continuously on the nanoparticles since pushed by a gas flow. The oxidation temperature of particulate trapped on the SiC-nanoparticle membrane was about 75 degrees lower than that on the conventional diesel particulate filters (DPF) without a catalyst.
Technical Paper

Lattice Boltzmann Simulation on Particle Transport and Captured Behaviors in a 3D-Reconstructed Micro Porous DPF

In this study, particle transport and captured behaviors in a Diesel Particulate Filter (DPF) was investigated with Lattice Boltzmann Method. LBM calculation was performed to a 3D-reconstructed micro porous DPF substrate, which was obtained by micro-focus 3D X-ray technique. Simulating advection-diffusion behaviors of diesel particulates in micro porous channel, we adapted a LBM method used for high Peclet number flow, simulating flow conditions in DPFs. We investigated flow behaviors in a wide variety of inlet velocity. LBM simulation has clearly shown that non-dimensional flow field is similar in wide range of flow conditions in the DPF, because flow Reynolds number in the micro porous substrate is sufficiently low, dominated by laminar flow regime. It was also revealed that less than 40% pore channels was responsible for more than 80% volume flux in the porous substrate without particle loading.
Technical Paper

Comparison Study on Fuel Properties of Biodiesel from Jatropha, Palm and Petroleum Based Diesel Fuel

The increase of air pollution and global warming is a threat for human life. Besides, the price of petroleum is increasing rapidly and the resources are diminishing. This obliged scientists and engineers to look for alternative sources of energy, which are cleaner and more sustainable. Biodiesel, defined as mono-alkyls of esters from vegetable oils and animals fat, is a cleaner renewable fuel and has been considered as the best alternative for petroleum based diesel fuel hence it can be used in any compression ignition engines without any significant modification. The main advantages of using biodiesel are its renewability and better quality of exhaust gas emissions due to their higher content of oxygen. The produce less soot and hence the feed stuck is plant it will regenerate the CO2 by the photosynthesis which ensures the renewability and reduces global warming.
Technical Paper

Characterization of Carbon Fiber and Glass Fiber’s Micro and Nanostructure Using Electron Microscopy, Raman Spectroscopy and XRD Analysis

Nowadays, most manufacturers are looking for the improvement of lightweight parts and other components in the automobile field. Carbon fiber and glass fiber are the most effective materials for their requirement to reduce the weight in vehicles due to their light weight and high tensile strength. The diameter of carbon fiber is 6 μm while glass fiber diameter is 17 μm. The mechanical tensile force of carbon fiber and glass fiber are 430 N and 290 N respectively on fiber alone without matrix. Carbon fibers are gradually smaller in each filament due to tensile force. Approximately 5 mm are elongated for both carbon fiber and glass fiber in tensile test report. In current research, characteristic and tensile force of carbon fiber and glass fiber were investigated by using electron microscopy, Raman spectroscopy and XRD.
Technical Paper

Impact of TiO2 and V2O5 on Sintered Mullite Porous Microstructure and Soot Oxidation Kinetics Using SEM and TGA

The exhaust emissions from diesel combustion are the sources of particulate matter emitted to the atmosphere, which are components of air pollution that implicated in human health such as lung cancer. At present the diesel particulate filter can remove PM from the exhaust gas before emitted to the atmosphere. This research is investigating morphology and structure of acicular mullite to develop the fabrication process filter in order to study particulate matters trapping and oxidation mechanisms. This paper used two main substances to study the structure of diesel particulate filter (DPFs); Aluminum oxide (Al2O3) and Silicon dioxide (SiO2). These are mainly in the conventional DPFs. The variable substances are Titanium dioxide (TiO2) and Vanadium oxide (V2O5), which added to investigate and produce the acicular mullite DPFs structure. The mullite samples were sintered at 1300 oC with holding time of 1 h.
Technical Paper

Investigation on Premixed Charge Compression Ignition Combustion Control Using Multi Pulse Ultrahigh Pressure Injection

Compression ignition (CI) engines provide higher thermal efficiency compared to other internal combustion engines although large amounts of NOx and soot are produced during combustion. NOx and soot emissions can be reduced by using Premixed Charge Compression Ignition (PCCI) combustion. However, the problems of PCCI combustion include limited operating range, unstable start of combustion and an increase in combustion noise. The multi-pulse ultrahigh pressure injection allows fuel to be injected near TDC, improving mixture formation and enhancing the possibility to extend the operating range of PCCI combustion. The objective of this paper is to control and extend the operating range of PCCI combustion using multi-pulse ultrahigh pressure injection. This has not been studied before. Combustion characteristics were investigated using apparent rate of heat release analysis, heat balance analysis, exhaust emission measurement and soot concentration measurement.
Technical Paper

Creation of Image on Diesel Spray and Flame by Means of Rapid Compression Machine and D.I Diesel Engine

The continous series of images on diesel spray and flame were created through the studies by means of using Rapid Compression Machine and D.I engine based on our latest data. 1. The image of diesel spray were elucidated through the study of thermodynamical global evaporation phenomena and the measurement of instantaneous distribution maps of spray fuel concentration by the high speed photo image analysis method at non-evaporated, evaporated states of free spray under the diesel condition at RCM. 2. The image of diesel flame were also obtained at the instantaneous distribution maps of temperature, soot and concentration of combustion products in the flame by means of photo image analysis method and gas sampling method at free and wall impinging spray flame with RCM and D.I engine.
Technical Paper

Effect of High Pressure Injection on Soot Formation Processes in a Rapid Compression Machine to Simulate Diesel Flames

The characteristics of diesel spray and flame in a quiescent atmosphere were studied as a function of injection pressure ranging from 30 to 110 MPa. Measurements included the spray form and Sauter mean diameter of a non-evaporating spray, the liquid phase penetration of an evaporating spray and the visualization of sooting zone in a flame. Experimental results show that high pressure injection improves the atomization and air entrainment of non-evaporating spray and that the liquid phase penetration of evaporating spray is hardly affected by injection pressure, demonstrating a promotion of evaporation with injection pressure. Visualization of the sooting zone in a flame made it clear that high pressure injection is advantageous in reducing soot formation and shortening the combustion duration.
Technical Paper

Development of a Rapid Compression-Expansion Machine to Simulate Combustion in Diesel Engines

A rapid compression-expansion machine which can simulate the combustion processes in diesel engines is developed. The configuration of the combustion chamber is a 100 mm bore and a 90 mm stroke, and the compression ratio is 15. The piston is driven by an electro-hydraulic system with a thrust of 90 kN and the maximum frequency of 20 Hz. The whole system composed of a hydraulic actuator, a fuel injection system, and a valve driving unit is sequentially controlled by a computer. The reproducibility of the stop position of the piston at the end of compression is achieved with an accuracy of ±0.1 mm by employing a hydraulic-mechanical brake mechanism. The experiment shows that the combustion in the expansion stroke is achieved, and that the combustion characteristics such as the rate of heat release and indicated output as well as the exhaust emission can be measured.
Technical Paper

A New Technique for the Measurement of Sauter Mean Diameter of Droplets in Unsteady Dense Sprays

A new technique is developed for the in-situ measurement of Sauter mean diameter of droplets in non-evaporating transient dense sprays. This method analyzes the image of a shadowpicture of a spray based on the incident light extinction principle, and allows the sizing of Sauter mean diameter of whole droplets in a transient spray with any shape. In addition, this method allows the measurement of the local droplet size in a quasi-steady region of an axisymmetric spray if the conservation equations regarding mass and momentum are included in the calculation and data analysis. A calibration was carried out using glass beads as test particles: this was proved to have an accuracy of Sauter mean diameter measurement within 10%, on average. Applications of the new technique to both diesel and gasoline (EFI) sprays have been made.
Technical Paper

Pyrene-LIF Thermometry of the Early Soot Formation Region in a Diesel Spray Flame

In order to investigate early soot formation process in diesel combustion, spectral analysis and optical thermometry of early soot formation region in a transient spray flame under diesel-like conditions (Pg2.8 MPa, Tg620-820K) was attempted via laser-induced fluorescence (LIF) from pyrene (C16H10) doped in the fuel. Pyrene is known to exhibit a temperature\-dependent variation of LIF spectrum; the ratio of S2/S1 fluorescence yields, from the lowest excited singlet state S1 and the second excited singlet state S2, depends on temperature. In the present study, pyrene was doped (1%wt) in a model diesel fuel (0-solvent) and the variation of LIF spectra from the pyrene in the spray flame in a rapid compression machine were examined at different ambient temperatures, ambient oxygen concentrations, measurement positions and timings after start of fuel injection.
Technical Paper

A Study on Effect of Heterogeneity of Oxygen Concentration of Mixture in a Combustion Chamber on Combustion and Emissions of Diesel Engine

In this study, the combustion characteristics of diesel flame achieved in a rapid compression and expansion machine (RCEM) at various patterns of oxygen distribution in the chamber are investigated in order to clarify the effect of heterogeneity of oxygen distribution in diesel engines induced by EGR on the soot and NOx emissions. To make the heterogeneous distribution of oxygen in a combustion chamber, the mixtures with different oxygen concentrations are injected through the each different port located on the cylinder wall. Results indicate that the amount of oxygen entrained into the spray upstream the luminous flame region affects the NO emission from diesel flame strongly.
Technical Paper

A Study of the Structure of Diesel Sprays Using 2-D Imaging Techniques

The structure of dense sprays was investigated using 2-D imaging techniques. To investigate the mechanism of atomization, the liquid phase in a non-evaporating spray was visualized by a thin laser sheet formed by a single pulse from a Nd:YAG laser at the distance from 4 to 19 mm from the nozzle orifice with the injection pressure and the surrounding gas density as parameters. A new technique for the visualization of vapor phase in an evaporating spray, the SSI (Silicone particle Scattering Imaging) method, was proposed to investigate the structure of the vapor phase regions of the spray.
Technical Paper

A Study on Soot Formation in Unsteady Spray Flames via 2-D Soot Imaging

The formation and oxidation processes of soot particles in unsteady spray flames were investigated in a quiescent atmosphere using 2-D laser sheet visualization. The mid-plane of a flame was illuminated twice during a short time-interval by a laser sheet from a double-pulsed YAG laser. An image pair of the scattered light from soot particles was taken by two intensified gated cameras in succession. The velocity vectors of soot clouds at various location in the sooting region were estimated using the spatial correlation between the image pair. The results of temporal and spatial variation of velocity and scattering intensity in the evolving soot clusters made it clear that soot is mainly formed in the periphery of the flame tip where the air entrainment is less and flame temperature favors soot formation.
Technical Paper

Effect of Coexistent Additives on the Friction Characteristics and Tribofilm formation of Zinc Dialkyldithiophosphate

The major aim of this study is to investigate the tribofilm formation and friction-speed characteristics of ZnDTP in the presence of other lubricant additives. Simultaneous measurement of friction and electrical conductivity were employed using ZnDTP and several kinds of functionally different additives. Several analyses of friction surfaces were also carried out in order to measure the reaction film thickness and investigate the chemical composition of this film. It was demonstrated that the presence of each additive with ZnDTP prevented the formation of a ZnDTP tribofilm and thereby could provide lower friction than ZnDTP alone.
Technical Paper

Quantitative Measurement of Fuel Vapor Concentration in an Unsteady Evaporating Spray via a 2-D Mie-Scattering Imaging Technique

The cross-sectional distribution of fuel vapor concentration in an evaporating spray was measured quantitatively by a new scattering imaging technique, silicone particle scattering imaging method, which was proposed in a previous paper[1]. When fuel containing silicone oil injected into a nitrogen environment at high temperature, the volatile base fuel in the droplets vaporized rapidly, leaving behind small droplets of silicone oil suspended in the vapor-gas mixture. The silicone oil droplets were illuminated by a thin laser sheet, and the scattered light was imaged by a CCD camera. The cross-sectional distribution of vapor concentration was estimated from the scattering image of the silicone oil droplets by Mie scattering theory. The results demonstrated clearly the inhomogeneity of the fuel vapor concentration. The distribution of vapor concentration was discontinuous, and islands of rich mixture with a scale of several millimeters existed in the center region of the spray.
Technical Paper

2-D Imaging of Fuel Vapor Concentration in a Diesel Spray via Exciplex-Based Fluorescence Technique

To measure the fuel vapor concentration in an unsteady evaporating spray injected into nitrogen atmosphere, the exciplex-forming method, which produces spectrally separated fluorescence from the liquid and vapor phase, was applied in this study. Two experiments were conducted to investigate the qualitative and quantitative applicability of the technique in a high temperature and high pressure atmosphere during the fuel injection period. One is to examine the thermal decomposition of TMPD dopant at a high temperature and a high pressure nitrogen atmosphere during a short period of time. The other is to calibrate the relationship between fluorescence intensity and vapor concentration of TMPD at different vapor temperatures. And then, the qualitative measurement of fuel vapor concentration distributions in diesel sprays was made by applying the technique.