bluuebunny/crossref_metadata_2025 huggingface dataset:
Placement Technique of Measurement Points for Inverse Acoustic Analysis
Authors: Oshima Hiroko , Ladin Hilmi Bin Hela , Ito Akihito , Tsujiuchi Nobutaka , Koizumi Takayuki
Published: November 2023

This paper describes a measurement points' placement technique for the sound source identification using inverse acoustic analysis. In order to reduce noise in NVH problem for various kinds of machines including small size engine, it is necessary to identify the sound source. The inverse acoustic analysis is a technique that is effective for the sound source identification.[1,2] The inverse acoustic analysis identifies a surface vibration of an object by measuring the radiated sound and solving the inverse problem. Nakano et al. researched about the location of sound pressure measurement points for accurate improvement.[3] They clarified that the sound pressure measurement points on the concentric circle gave more accurate surface vibration than the measurement points on the square lattice. In this paper, we proposed a measurement points' placement technique based on the space filling design.[4,5] The placement of the measurement points with the space filling design has the following merits; (1) Enables to decide a number of measurement points according to the experiment. This characteristic is superior to location on the square lattice. (2) Enables to predict the surface vibration of a rectangular object. This characteristic is superior to location on the concentric circle. In this paper, we show that the precision of the measurement points' placement with the space filling design and the measurement points' placement by the conventional technique are at the same level. Furthermore, the design criterions of space filling design are discussed from the viewpoint of the measurement points' location and the optimization of design criterion is discussed to locate measurement points.
CFD Analysis of the Effect of the Injection Pressure on a Small 2S LPDI Engine
Authors: Balduzzi Francesco , Vichi Giovanni , Romani Luca , Ferrara Giovanni
Published: November 2023

The paper investigates the influence of the fuel injection pressure on a small two-stroke engine with low pressure direct injection (LPDI). The authors in previous studies showed the benefits of the LPDI system in reducing the fuel short circuit, both from an experimental and numerical point of view. As a direct consequence, both the specific fuel consumption and the pollutant emissions were notably reduced, reaching the typical performance of a standard four-stroke engine of comparable size.

The main drawback of the system is the limited time at disposal for delivering the fuel with difficulties in achieving a satisfactory air-fuel mixing and homogenization as well as fuel vaporization.

In order to overcome the aforementioned issues, a detailed numerical analysis is carried out by performing a wide set of CFD simulations to properly investigate and understand the many complex phenomena occurring during the interaction between the injected fuel and the fresh scavenging air. Starting from the reference configuration working with a fuel delivery pressure of 5 bar, lower and higher injection pressures are considered. The higher pressure (10 bar) is investigated to evaluate the effects of shortening the injection duration and increasing the fuel atomization. The lower pressure (3 bar) is investigated to evaluate the effects of distributing the total amount of delivered fuel along a wider crank angle range and of increasing the interaction with the fresh air. Different engine operating conditions are analyzed by varying the engine speed and load.
Additive Technology for Superior and Unique Motorcycle Oil (SUMO)
Authors: Lim Pei Yi , Huang Huai Hui , Richard Katherine M.
Published: November 2023

In a market survey conducted in 2010 on major South East Asian cities, motorcycle users identified some of the most valued oil features being clutch friction, durability and engine cleanliness. In the fast growing motorcycle markets of Asia where motorcycles are used mainly for daily transportation needs, there are enormous opportunities for motorcycle oils delivering differentiated attributes that provide superior reliability to the end users. It was with this market perspective that this new additive technology was developed.

The additive technology was developed based on a unique set of components and formulation approach to meet the lubrication challenges of motorcycles, particularly its high shear and temperature conditions. In a forward-looking standpoint, the development was aligned to the current energy conservation and environmental trends in the personal mobility oil segment. Hence, the technology was formulated in SAE 5W-30 with an opportunity for fuel economy credits from the lower viscometrics. The additive was also developed in the lower phosphorous range of the JASO specification to be positioned as a lower SAPS catalyst compatible additive. With the lower phosphorous and viscosity grade, durability trade off was a concern. However, the additive technology demonstrated excellent durability performance, as shown from results in the modified FZG Pitting Test, extended JASO T903 Friction Test, API SN demonstration program (with extended Sequence IVA) and a field test in Thailand. In addition to durability, the additive technology also showed excellent engine cleanliness and sludge control performance. The results of this extensive performance evaluation activity will be presented in detail in this paper.

In conclusion, the oil formulated with this additive technology delivered key differentiated attributes highly valued by motorcycle users i.e. clutch friction, engine cleanliness and pitting protection, with these superior performance attributes enabled by the unique set of components and formulation approach. This project was a successful technology demonstration of a motorcycle oil additive which was developed to meet today's performance needs of end-users, aligned with the broader trends in the personal vehicle lubricant market.
Comparison Method of Input Powers and Contribution Rates between Statistical Energy Analysis and Transfer Path Analysis for Small Power Generator's Enclosure
Authors: Ladin Hilmi Bin Hela , Tsujiuchi Nobutaka , Kuroda Katsuhiko , Ito Akihito
Published: November 2023

This paper describes the comparison method of input powers and contribution rates from vibration sources to a small power generator's enclosure represented by a thin-walled plane structure determined by Statistical Energy Analysis (SEA) and Transfer Path Analysis (TPA). In the pursuit of efficient ways to analyze the design dynamics of small machines such as a small power generator, it is important to identify information and dynamics of input power sources during machine operation. SEA and TPA are two of the most efficient methods in identifying the dynamics of a structure during machine operation. SEA is used for systems with many resonant modes, and predicted results are based on space averages. On the other hand, TPA is based on estimation of a frequency response function between an excitation point and a response point. In this study, we proposed a method to compare SEA evaluated by power injection method and TPA evaluated by matrix inversion method. The method is validated through numerical analyses, using a finite element method (FEM). We focused our research on the enclosure of a power generator and simplified it by constructing a partial enclosure model of a simple structure consisting of two L-shaped plate structure. In order to verify the practicality of this method, an experimental verification was conducted. As a result, the input powers are quantitatively similar between SEA and TPA. Furthermore, the contribution rates from the power sources between SEA and TPA are qualitatively similar without having to consider the response phase.
Influence of Internal EGR on Knocking in an HCCI Engine
Authors: Shimada Takashi , Yoshida Yuki , Rin Chibin , Yamada Masanori , Ito Naoya , Iijima Akira , Yoshida Koji , Shoji Hideo
Published: November 2023

Homogeneous Charge Compression Ignition (HCCI) engines have attracted much attention and are being widely researched as engines characterized by low emissions and high efficiency. However, one issue of HCCI engines is their limited operating range because of the occurrence of rapid combustion at high loads and misfiring at low loads. It is known that knocking accompanied by in-cylinder pressure oscillations also occurs in HCCI engines at high loads, similar to knocking seen in spark-ignition engines. In this study, HCCI combustion accompanied by in-cylinder pressure oscillations was visualized by taking high-speed photographs of the entire bore area. In addition, the influence of internal exhaust gas circulation (EGR) on HCCI knocking was also investigated. The visualized combustion images revealed that rapid autoignition occurred in the end-gas region during the latter half of the HCCI combustion process when accompanied by in-cylinder pressure oscillations. It was also found that applying internal EGR had the effect of moderating combustion by delaying the ignition timing, thereby suppressing in-cylinder pressure oscillations.
Expansion to Higher Efficiency - Experimental Investigations of the Atkinson Cycle in Small Combustion Engines
Authors: Pertl Patrick , Trattner Alexander , Stelzl Reinhard , Lang Michael , Schmidt Stephan , Kirchberger Roland
Published: November 2023

The enhancement of efficiency will play a more and more important role in the development of future (small) internal combustion engines. In recent years, the Atkinson cycle, realized over the crank drive, has attracted increasing attention. Several OEMs have been doing investigations on this efficiency-increasing principle with in the whole range from small engines up to automotive ones.

In previous publications, the authors stated that an indicated efficiency of up to 48% could be reached with an Atkinson cycle-based engine. However, these studies are based on 1D-CFD simulation. To verify the promising simulation results, a prototype engine, based on the Atkinson principle, was designed and experimentally tested. The aim of the present study is to evaluate and validate the (indicated) engine efficiency gained by experimental tests compared to the predicted simulation results. In order to investigate part load behavior, several valve timing strategies were also developed and tested.

This publication gives a brief overview of the specific engine layout of the Atkinson prototype engine. The main part deals with experimental investigations of several defined load points and the thermodynamic evaluation of the measured data concerning heat release, wall heat and gas exchange etc.

The results of this study indicate a high indicated efficiency at full load. However, the effective efficiency suffers, especially at higher engine speeds. For part load operation, the exhaust valve timing is essential to achieve high efficiency. The publication further indicates that small internal combustion engines using the Atkinson cycle could be an interesting alternative for future internal combustion engine applications.
Study on the Effects of EGR Supply Configuration on Cylinder-to-Cylinder Dispersion and Engine Performance Using 1D-3D Co-Simulation
Authors: Dimitriou Pavlos , Burke Richard , Copeland Colin D. , Akehurst Sam
Published: November 2023

Exhaust Gas Recirculation (EGR) is widely used in IC combustion engines for diluting air intake charge and controlling NOx emission. The rate of EGR required by an engine varies by the speed and load and control of the right amount entering the cylinders is crucial to ensure good engine performance and low NOx emission. However, controlling the amount of EGR entering the intake manifold does not ensure that EGR rate will be evenly distributed among the engine's cylinders. This can many times lead to cylinders operating at very high or low EGR rates which contradictory can deteriorate particulate matter and NOx emission.

The present study analyses the cylinder-to-cylinder EGR dispersion of a 4 cylinder 2.2L EUROV Diesel engine and its effects on the combustion stability. A 1D-3D coupling simulation is performed using GT-Power and STAR-CCM+ to analyze the effects of intake manifold geometry and EGR supply configuration on the EGR homogeneity and cylinder-to-cylinder distribution.

The results confirm that the EGR supply configuration plays a key role on the intake air charge homogeneity and as a result to the EGR cylinder-to-cylinder distribution and combustion stability. The turbulence flow created at the point of EGR diffusion was found to be the governing factor influencing the performance of an EGR mixer. Small air-EGR “contact” areas, Venturi shape and high pressure differences contribute towards the increase of turbulence kinetic energy at the EGR injection area.
Adaptation of Turbocharger to Small Displacement Single Cylinder SI Engine
Authors: Chaoran Duan , Fujita Yujiro , Ichiyanagi Mitsuhisa , Suzuki Takashi
Published: November 2023

This paper represents the adaptation of turbo charger to single cylinder 450cc SI engine which is used for the student formula competition. The experiment and 1D engine simulation called as GT-Power were performed to confirm the effect of valve profile, compression ratio and air fuel ratio on the engine performance under the naturally aspirated condition. The maximum valve lift of the intake valves increased 27% and that of the exhaust valves increased 15% as compared with the low profile cam. The compression ratio was increased from 12.3 to 13.5 by changing the piston top land length in order to improve the thermal efficiency. It was confirmed that the torque peak was moved from 6000 rpm to 8000 rpm by changing the valve profile. Furthermore, turbo charger was adapted to the engine as changing the capacity of the turbocharger, the maximum boost pressure and the air fuel ratio. The capacity of the turbocharger was changed with expansion and contraction of the performance map of RHF25 manufactured by IHI Corporation. The genuine capacity of RHF25 worked along the better operation line in the compressor at all engine speed ranges. The intake pressure of 2.0bar abs worked along better operation line in the compressor and showed the reasonable pressure ratio of the turbine. The temperature at the entrance of the turbine shows the maximum value under the stoichiometric mixture condition, and it became lower as the rich mixture condition. As a result of the analysis, the maximum torque was improved about 7.7% at 8000 rpm and the maximum power was improved about 29.5% at 10000 rpm compared with the naturally aspirated condition by adapting the turbocharger to the single cylinder SI engine.
Combustion Characteristics of Diesel Spray with Temporally-Splitting High-Pressure Injection
Authors: Nishioka Yusuke , Tomoda Heizo , Nishida Keiya , Ogata Youichi , Kishorkumar Gnanasekaran , Shi Baolu
Published: November 2023

The effect of temporally-splitting high pressure injection on Diesel spray combustion and soot formation processes was studied by using the high-speed video camera. The spray was injected by the single-hole nozzle with a hole diameter of 0.11mm into the high-pressure and high-temperature constant volume vessel. The free spray and the spray impingement on the two dimensional (2D) piston cavity wall were examined. Injection pressures of 100 and 160 MPa for the single injection and 160 MPa for the split injection were selected. The flame structure and soot formation process were examined by using the two-color pyrometry. The soot generated in the flame under the split injection under 160 MPa becomes higher than that of the single injection under 160 MPa. However when comparing between the split injection of 160 MPa and the single injection of 100 MPa, the split injection reduces the soot in the free spray, whereas the split injection increases the soot in the two dimensional (2D) piston cavity impinging spray flame. The high pressure split injection shows an ability to reduce soot faster than that of the single injection under the same injection pressure.
Effects of Injection Timing and Injection Pressure on Combustion Characteristics and Emissions of Ethanol ED95 under Partially Premixed Combustion Condition
Authors: Chumueang Rachen , Laoonual Yossapong , Chollacoop Nuwong
Published: November 2023

The purpose of this study is to investigate the effects of injection timing and injection pressure on combustion characteristics and emissions of the direct injection single cylinder CI engine fueled with ethanol ED95 fuel (95% hydrous ethanol blended with 5% commercial additive by volume) under partially premixed combustion condition. The engine was modified to increase the compression ratio from 18 to 28. The experiment was tested at maximum engine load under a constant engine speed for all testing conditions.

The experimental results show a lower coefficient of variation (COV) for the indicated mean effective pressure (IMEP), which implies that higher combustion stability is achieved when the injection timing is advanced. However, the ignition delay significantly increases. In addition, when injection timing is advanced and the injection pressure is increased, THC and CO emissions increase due to lower combustion efficiency. Despite limitation of working operation at high load on ED95, it is remarkable to note that the indicated thermal efficiency of all ED95 experiments are achieved slightly higher compared to diesel.
Tuning for FSAE Engine with a Supercharger
Authors: Fukuoka Tadamasa , Fujimoto Kazuki , Hongo Yuya , Kajiwara Shinji
Published: November 2023

Kinki University formula project has been participating in the student Formula SAE of Japan (JSAE) every year for the Competition since the second time. The engine uses ZX-6R made by Kawasaki Heavy Industries for the Competition from the eighth time. “Improvement of limited performance” is inserted in the concept through the development of a power train. Supercharger loading, engine dry sump and engine cooling management were improved.

59.6 kW (80.6 PS) /9000 rpm of maximum output and 70.6 Nm (7.2 kgf m)/8000 rpm of maximum torque were achieved by the supercharger loading. We succeeded in getting 90% of torque band (4000∼10000rpm) by 50% of the number of revolutions in regular use (2000∼12000rpm).

Using the dry sump system, hydraulic pressure constantly managed hydraulic pressure at the time of engine operations; the system, where the engine stops at the time of hydraulic pressure fall, was also built. It was possible to lower the engine loading location by dry sump at 80 mm, and we contributed to the lower center of gravity of the vehicle. Even when the engine was not in motion by making the water pump electromotive force, it was possible to make it circulate through cooling water; it was possible to establish a cooling system in accordance with the Competition.
Downsizing of Fuel Injection Components for Small Motorcycles
Authors: Miyauchi Naoto , Enomoto Takeshi , Kato Yukinori , Miura Satoshi
Published: November 2023

In recent years, more and more small motorcycles, such as scooters, are introducing Fuel Injection System (FI system) worldwide. As motorcycles have limited component spaces, it is not easy to put the fuel supply system products such as Fuel Pump Module (FPM) and Fuel Injector intended for four-wheel vehicles. Therefore, downsizing of these components are being required. In addition, weight reduction is also an important design factor in terms of improvement in fuel efficiency and driving performance. To meet these needs, we focused on motorcycles to optimize the design. We have been standardizing these components and starting mass-production in order since 2002. This paper introduces FPM and Fuel Injector that were newly developed for motorcycles.
Innovative Carburetor Design with Dynamic Air to Fuel Ratio (AFR) Control for Improved Fuel Economy and Reduced Emissions
Authors: Simmons Timothy C. , Markoski Larry J.
Published: November 2023

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.
The Effect of Tempering Conditions on the Delayed Fracture Characteristics of Carburized Steels
Authors: Inoue Yoichi , Ohta Toshiya , Kurita Hirotaka
Published: November 2023

A carburizing is widely applied for many kinds of engine components for motorcycles. On the other hand, a delayed fracture phenomenon of strengthened steel materials occurred under actual usage is a serious concern. The delayed fracture characteristics of surface modified steels such as a carburized steels followed by a tempering have a difficulty being evaluated by only measuring a partial characteristic of the hardened portion due to the existence of an inhomogeneity of a microstructure and a gradient of strength. Therefore, the studies on the characteristics of the delayed fracture of the surface modified steels are not so many.

In this paper, the authors evaluated the delayed fracture characteristics of carburized and tempered actual components by comparing hydrogen desorption curves acquired with a thermal desorption spectroscopy using hydrogen-charged specimens with changing tempering conditions. The results from this survey indicates that the delayed fracture characteristics have a relationship with the microstructural transformation of the tempered martensite depending on the tempering conditions for the carburized steels.
A Theoretical Study of Interaction between Platinum and Oxide Support for Exhaust-Gas Purification Catalyst
Authors: Miura Kazuya , Tsuda Toyofumi , Hikasa Akio , Minokoshi Hiroyuki , Kimata Fumikazu , Watanabe Ryo , Fukuhara Choji
Published: November 2023

We investigated the interaction between the platinum and oxide support based on the HSAB (Hard-Soft-Acid-Base) concept to obtain guidelines for a superior exhaust-gas purification catalyst. The Density Functional Theory (DFT) calculation provided the chemical potential (μ) and chemical hardness (η) via the eigenvalue of the Valence Band Maximum and Conduction Band Minimum. Moreover, it was found that the interaction depends on the μ and η, e.g., the metallic Pt cluster (Pt1, Pt3) had a greater interaction with the oxide supports having a lower η, on the other hand, the oxidized Pt cluster (Pt1O1, Pt1O2, Pt1O3, Pt1O4, Pt3O6) tends to be stabilized on the oxide support with a higher μ. These results could be explained by the HSAB concept. It was also found that the oxidation energy of the supported Pt cluster well corresponds to the actual valency of the supported Pt, furthermore, the particle size of the Pt after the thermal treatment depends on the μ of the oxide supports. The activities of the Pt catalysts were successfully analyzed by a regression analysis. The activities of the supported Pt catalysts also depended on the μ and η values. Hence, the catalytic activities might be predicted by estimation of μ and η, i.e., the DFT calculation should be able to accelerate the development of the exhaust-gas purification catalyst with a higher efficiency and reasonable cost.
Influence of Pressure Conditions in Supercritical Atmosphere on Flame Diameter of Diesel Oil and Hexadecane Droplet
Authors: Mino Takuya , Enomoto Hiroshi , Hieda Noboru , Teraoka Yoshikazu
Published: November 2023

Liquid fossil fuels such as gasoline, diesel oil, and kerosene are widely used as a fuel of various transportation apparatus and generating electricity apparatuses including the automobiles. The spray combustion has been widely used for internal combustion engine to use the fuel efficiently. But some parts of the phenomenon are not elucidated because this combustion method is complicated phenomenon. To elucidate this phenomenon, there are many ways of analyzing droplet. For example, observing a single droplet which suspended by a catenary or under the microgravity. However, those methods are not enough simulation of a real droplet in the internal combustion engine. In this study, we developed an apparatus which could inject a freedom droplet of diameter about 30µm. It is considered that the droplet is in a real internal combustion engine. And the apparatus was installed in a container which could realize elevated temperature and pressure. And a droplet was injected under supercritical condition that simulated the condition in the internal combustion engine and combustion behavior was observed. We experimented with Diesel oil and hexadecane which is a surrogate fuel of Diesel oil. The influences of the combustion area of the droplet, the burning time, and the luminance value at the time of combustion were investigated. As a result, it was found that when the same fuel was burned under the same temperature condition under the supercritical condition, the maximum combustion area increased.
A Study of Autoignition Behavior and Knock Intensity in a SI Engine under Different Engine Speed by Using In-Cylinder Visualization
Authors: Takahata Shuhei , Ishikawa Takahiro , Yamashita Takahiro , Kudo Takuya Izako Hiroki , Shimizu Kento , Iijima Akira , Shoji Hideo
Published: November 2023

Internal combustion engines have been required to achieve even higher efficiency in recent years in order to address environmental concerns. However, knock induced by abnormal combustion in spark-ignition engines has impeded efforts to attain higher efficiency. Knock characteristics during abnormal combustion were investigated in this study by in-cylinder visualization and spectroscopic measurements using a four-stroke air-cooled single-cylinder engine. The results revealed that knock intensity and the manner in which the autoignited flame propagated in the end gas differed depending on the engine speed.
Simulation Based Optimization of a Motorcycle Drive Train by the Integration of a Novel Continuously Variable Planetary Transmission
Authors: Tromayer Jürgen , Gaber Michael , Kirchberger Roland , Thomassy Fern , McBroom Scott
Published: November 2023

Meeting upcoming emission limits such as EURO 5 with comparatively simple and low-cost vehicles will be very challenging. On the engine side, a big effort in terms of fuelling, combustion optimization as well as exhaust gas aftertreatment will be necessary without any doubt. Besides that, additional system optimization potential can be gained by a systematic adaptation of the drive train. One approach is to use a CVT (Continuously Variable Transmission) system to run engines in specific ranges with good fuel economy. However, existing belt driven CVTs show comparatively poor efficiencies. To overcome this drawback, the integration of a novel Continuously Variable Planetary Transmission (CVP), designed and developed by Fallbrook Technologies, was investigated in detail. For this purpose, a longitudinal dynamics simulation in Matlab-Simulink was carried out to compare a standard mass production vehicle drive train with several CVP setups.
Detailed Study of Hazard Analysis and Risk Assessment of ISO 26262 for Motorcycles
Authors: Hasegawa Makoto , Kaneko Takanobu
Published: November 2023

ISO 26262, an international functional safety standard of electrical and/or electronic systems (E/E systems) for motor vehicles, was published in November 2011 and it is expected that the scope will be extended to motorcycles in a second edition of ISO 26262 going to be published in 2018. ISO/DIS 26262 second edition published in 2016 has Part 12 as a new part in order to apply ISO 26262 to motorcycle. Proper estimation of Exposure, Controllability, and Severity in accordance with ISO/DIS 26262 Part 12, are key factors to determine Motorcycle Safety Integrity Level. To estimate precise these factors, there would be a case that it might not be appropriate to apply studies done for passenger car to motorcycle, and it would be necessary to apply motorcycle specific knowledge and estimation methods. In our previous studies we clarified these motorcycle specific issues and studied the method for the adaptation. In this study we executed Hazard Analysis and Risk Assessment and estimated Exposure, Controllability and Severity based on the knowledge and methodology we have accumulated. The motivation of our work are to show precise Exposure, Controllability and Severity estimation with concrete rationales, and contribute to motorcycle industry's functional safety application.
An Effect of Bio Diesel Fuel for Low Compression Ratio Diesel Engine
Authors: Yamada Hikaru , Yoshida Koji
Published: November 2023

The purpose of this study is to explore an effect of the coconut oil methyl ester (CME) and vegetable oil methyl ester (VME) on a low compression ratio diesel engine performance. CME and VME were produced from coconut oil and vegetable oil with methanol, respectively. Vegetable oil was assumed to contain 60 wt.% of soybean oil and 40 wt.% rapeseed oil. The engine performance was measured in the steady operating condition at 3600 rpm of engine speed. The ignition timings of CME and VME were advanced and the maximum cylinder pressures of CME and VME were higher as compared with the diesel fuel at low compression ratio, because CME and VME consisted of medium chain fatty acid methyl esters. The ignitability of CME was superior to VME, because CME consisted of saturated fatty acid. The brake thermal efficiency of diesel fuel was slightly higher than CME and VME at any compression ratios. THC and CO concentrations of CME and VME were lower than diesel fuel at low compression ratio, because CME and VME were oxygenate fuel. THC and CO concentrations of CME were lower than VME, because CME had more oxygen than VME. NOx concentration of CME was lower than diesel fuel and VME for any compression ratios in the high load operation, because the maximum rate of heat release of CME was lower than diesel fuel and VME. Therefore, CME and VME could be adaptable as alternative fuel for a low compression ratio diesel engine.
Spectroscopic Investigation of Initial Combustion Stages in a SI Engine Fuelled with Ethanol and Gasoline
Authors: Di Iorio S. , Irimescu A. , Merola S.S. , Sementa P. , Vaglieco B. M.
Published: November 2023

It is well known that ethanol can be used in spark-ignition (SI) engines as a pure fuel or blended with gasoline. High enthalpy of vaporization of alcohols can affect air-fuel mixture formation prior to ignition and may form thicker liquid films around the intake valves, on the cylinder wall and piston crown. These liquid films can result in mixture non-homogeneities inside the combustion chamber and hence strongly influence the cyclic variability of early combustion stages. Starting from these considerations, the paper reports an experimental study of the initial phases of the combustion process in a single cylinder SI engine fueled with commercial gasoline and anhydrous ethanol, as well as their blend (50%vol alcohol). The engine was optically accessible and equipped with the cylinder head of a commercial power unit for two-wheel applications, with the same geometrical specifications (bore, stroke, compression ratio). Ultra-violet (UV) natural emission spectroscopy measurements ranging from 250nm to 470nm wavelength and simultaneous thermodynamic analysis were used to better understand the effect of ethanol content on flame kernel inception and development. All experiments were conducted at wide open throttle (WOT), with stoichiometric air-fuel mixtures, fixing the engine speed at 2000rpm. Optical investigations allowed to follow the evolution of chemical species that marked the spark discharge (cyano CN and hydroxyl OH radicals) as well as flame front initial growth (OH and carbyne CH radicals). Vibrational and rotational temperatures were calculated during the arc and glow phase by the ratio between the emission intensity of CN and OH radicals. Results were compared with adiabatic flame temperature traces obtained by applying a two zone model.
Effect of Biofuel and Soot on Metal Wear Characteristic Using Electron Microscopy and 3D Image Processing
Authors: Karin Preechar , Amornprapa Warawut , Khamsrisuk Phiranat , Budsayahem Pol-ake , Chammana Pattara , Sriprapha Kobsak , Hanamura Katsunori
Published: November 2023

The soot contamination in used engine oils of diesel engine vehicles was about 1% by weight. The soot and metal wear particle sizes might be in the range of 0-1 µm and 1-25 µm, respectively. The characteristics of soot affecting on metal wear was investigated. Soot particle contamination in diesel engine oil was simulated using carbon black. Micro-nanostructure of soot particles were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and laser diffraction spectroscopy (LDS). The metal wear behavior was studied by means of a Four-Ball tribology test with wear measured. Wear roughness in micro-scale was investigated by high resolution optical microscopy (OM) , 3D rendering optical technique and SEM image processing method. It was found that the ball wear scar diameter increased proportionally to the soot primary particle size. The effect of biodiesel contamination were also increasing in wear scar diameter.
Effect of Fuel Injection Parameters on Performance and Emission Characteristics in HCCI Engine - A CFD Study
Authors: Guru Kiran H. R. , Mallikarjuna J. M.
Published: November 2023

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. All the CFD simulations are carried out from the inlet valve opening (IVO) to the exhaust valve opening (EVO) period, at the engine speed of 1500 rev/min., with the compression ratio of 16:1. Here, homogeneous mixture is achieved by the injection of fuel into the engine cylinder directly during the early compression stroke, with the fuel injection pressure of 800 bar. The analysis is carried out to study the effect of multiple fuel injection strategy, fuel mass split ratio, injection timing and pressure on the performance and emission characteristics of the engine. In addition, the results of the HCCI mode are compared with that of the conventional CI engine operating at the same load conditions.

From the results, it is found that, the HCCI mode with three-stage fuel injection having fuel mass split ratios of 40-50-10%, fuel injection timings of 260, 300 and 360 CAD, and fuel injection pressure of 1200 bar shows higher indicated thermal efficiency by about 1.2% and lower NOx emissions by about 81.9% compared to that of conventional CI engine mode.
Modeling of Unsteady Heat Transfer Phenomena at the Intake Manifold of a Diesel Engine and Its Application to 1-D Engine Simulation
Authors: Yilmaz Emir , Joji Hayao , Ichiyanagi Mitsuhisa , Suzuki Takashi
Published: November 2023

In the past two decades, internal combustion engines have been required to improve their thermal efficiency in order to limit hazardous gas emissions. For further improvement of the thermal efficiency, it is required to predict the mass of intake air into cylinders in order to control the auto-ignition timing for CI engines. For an accurate prediction of intake air mass, it is necessary to model the heat transfer phenomena at the intake manifold. From this intention, an empirical equation was developed based on Colburn equation. Two new arguments were presented in the derived formula. The first argument was the addition of Graetz number, where it characterized the entrance region thermal boundary layer development and its effect on the heat transfer inside the intake manifold. As the second argument, Strouhal number was included in order to represent intake valve effect on heat transfer. This study compared experimental data with the present empirical equation, and average error was estimated to be 3.1%, which was significantly improved in comparison with the Colburn equation. Furthermore, derived empirical heat transfer equation was implemented to the intake manifold model of a diesel engine in 1-D engine simulation. The study confirmed the influence of the heat transfer phenomena, and its importance to intake air. At IVC, temperature difference between Colburn equation and derived equation was calculated to be 3.8 K. This corresponded to an advanced auto-ignition timing by 0.78 deg. CA, which gives an estimated improvement of 0.22% when evaluating both the thermal efficiency and CO2 emission.
Development of a Fuel Injection Strategy for a Diesel Engine Fumigated with Ethanol
Authors: Painrungrot T. , Charoenphonphanich C. , Kosaka H. , Tongroon M.
Published: November 2023

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%.
Effects of Spark Discharge Characteristic on Cycle-to-Cycle Variations of Combustion for Lean SI Operation with High Tumble Flow
Authors: Sasaki Kosaku , Jung Dongwon , Yokomori Takeshi , Iida Norimasa
Published: November 2023

It has been shown that lean burn is effective for improving the thermal efficiency of gasoline SI engines. This happens because the reduction of heat loss by decrease of flame temperature. On the other hand, the fuel dilution of the premixed gas makes the combustion speed low, and cycle-to-cycle variations of combustion are increased by excessive dilution, it is difficult to increase the thermal efficiency of the gasoline SI engine. Influence of ignition by spark discharge is considered as a factor of combustion variation, and it is necessary to understand the effects of spark discharge characteristics on the lean combustion process. Spark discharge in the SI engines supplies energy to the premixed-gas via a discharge channel in the spark plug gap which ignites the premixed-gas. The discharge channel is elongated by in-cylinder gas flow and its behavior varies in each cycles. When the discharge channel is elongated, the premixed-gas on the discharge channel increases and the gap resistance increases. As a result, the pattern of the discharge energy supply to the premixed gas by the spark discharge also changes in each cycle. It may affect the lean-burn combustion process. However, the relationship between spark discharge and combustion has not been clarified.

In this study, using an ignition system with 10 ignition coils and an adapter for intensify the tumble flow, we photograph the behavior of the discharge channel with a visualization engine. The relationship between discharge channel length and gap resistance are clarified. Then combustion experiments were carried out, discharge current, discharge voltage and in-cylinder gas pressure were measured at the same time. We investigated the influence of gap resistance on the combustion phase

As a result, there was a correlation between the discharge channel area and the gap resistance. It is possible to estimate the spark discharge channel area from the gap resistance, by measuring the discharge voltage and the discharge current without using the visualization device. When the average gap resistance was more than 45 kΩ , CA 5 became 0 deg.ATDC or less except for 1 cycle. Therefore, it was revealed that combustion was promoted when the discharge channel was stretched and the gap resistance was large.
Heat Transfer Analysis in a Diesel Engine Based on a Heat Flux Measurement Using a Rapid Compression and Expansion Machine
Authors: Kuboyama Tatsuya , Moriyoshi Yasuo , Kosaka Hidenori
Published: November 2023

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.
VAVE Design of Anti-Hop Clutch for Motorbikes
Authors: Jahagirdar Ashutosh , Kharul Ravindra , Bhone Nitin , Kulkarni Ashok
Published: November 2023

Anti-Hop Clutches are popular for bikes above 400 cc. They offer the advantage of better driving stability in lower gears and during down shifting. The currently used designs of such clutches are having different constructions with complex geometry parts and almost 30% more number of parts (compared to standard clutch) are used in some designs to achieve the desired 'Driving Assist' and 'Coasting Slip' effect. The production process used, demands for specialized tools for manufacturing the complex geometry of parts and the price of the clutch assembly is more than double as compared to standard, equivalent design of multi plate wet clutches. These type of clutches are commonly known as - Anti Hop Clutch or Slipper Clutch or Assist and Slip clutches.

To achieve same performance benefits with simpler design, less number of parts with a Flexibility to alter the Assist and Slip effect to suit the application, Endurance Technologies Ltd. developed a new concept. The simplicity of design and enhanced effect of Assist and Slip is experienced on vehicle trials. Further the design can be optimized to meet the expected performance and durability targets of the intended application.

In this paper the details of concept clutch construction, Mathematical models developed, Performance and durability measurements taken on the vehicle are summarized which is trademarked as Endurance Variable Torque Clutch (EVTC®). The evaluation of different variables on performance is discussed and to achieve the performance within a narrow tolerance band the special design considerations utilized are elaborated. For achieving better ergonomic effect on Clutch lever, the clutch uses a pair of diaphragm spring which is assembled so as to inherently reduce the variations in clutch performance over the life span.

Due to above advantages of design, the EVTC cost is approximately 65% of popular Slipper clutches, while achieving better or equal performance and durability. Compared to standard (Non Slipper) design of clutches, this clutch has indicated 100% improvement in road endurance life due to operation in optimum working pressure on Friction Plates. The modularity of this design also provides the possibility of adapting the same clutch configuration on vehicles with varying capacity (say 150 cc to 250 cc) with change of only friction material and machining parameters of assist and slip affecting helix angles, reducing the development time. Above benefits increase the feasibility of implementation on lower capacity engines, especially to suit the sporty type riding habits of end users.
Thin Wall Austempered Ductile Iron Connecting Rod for Lighter Automotive Component - Production of Thin Wall Ductile Iron Connecting Rod
Authors: Sulamet-Ariobimo Rianti , Yudha Gregah , Sukarnoto Tono , Mujalis Yusep , Oktaviano Yoska
Published: November 2023

Lighter automotive components are produced to respond to global issue regarding energy. Lighter components can be achieved by replacing the material to those known as lighter material such as aluminium or applying thin wall casting technique. Lightweight automotive components will mean lower fuel consumption. Based on the success in making thin wall ductile iron plate (TWDI) with a thickness to 1 mm using a vertical casting, it encourages the implementation of the design to create lightweight automotive components. The design was applied to produce a thin wall two-cylinder engine ductile iron connecting rod which will be upgraded with austempering process. This connecting rod will be applied in Vespa PX150. The designs were simulated in Z-Cast simulation software and analyzed to determine the most optimum design. The chosen design was casted in a foundry to match the simulation. Evaluation of the characteristics will be run in the second stage of the research.
Developing High-Performance Motorcycle Oils
Authors: Marcella Mike , Johnson Aaron
Published: November 2023

Published motorcycle lubricant research often focuses on developments to meet certain specifications, regulatory requirements, or a combination of the two. Seemingly missing from the literature is research where the primary goal is development of a lubricant that enables maximum torque, power and acceleration from a machine for the purpose of winning races. The present study combines the two areas of research, where a high-performance motorcycle engine oil platform is developed to be used in competition, while simultaneously meeting the necessary regulations and specifications to be useful for commuters and leisure riders alike. Well-known are the demands on a motorcycle oil, which must lubricate and protect the crankcase, clutch and gears, all of which have competing requirements such that a strategy to improve the performance in one area can cause a detriment in another. Formulating for racing engines that are typically much more powerful than production versions further exacerbates these dichotomies, where the traditional strategies for gaining power through the lubricant of reducing viscosity or adding friction-reducing chemistries can leave the clutch and gears open to severe damage. To meet these competing demands, a novel additive system with unique anti-wear and friction modifier chemistries was introduced to ensure clutch and gear protection while simultaneously improving power output and minimizing deleterious effects to aftertreatment devices. Further, the oils were designed to withstand the higher temperatures, speeds and power densities found in high performance machines through improved antioxidants, base stocks and shear-stable polymers, which also provide durability across the oil drain interval for leisure riders and commuters alike. Through a combination of performance bench testing, engine dynamometer testing and field testing on the track, it was demonstrated that substantial power gains can be achieved while still maintaining hardware protection, thus achieving the goal of a high-performance racing oil that is also suitable for everyday use.