Browse Topic: On-board energy sources

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This document defines a set of standard application layer interfaces called JAUS Unmanned Ground Vehicle Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Unmanned Ground Vehicle Services represent the platform-specific capabilities commonly found in UGVs, and augment the Mobilty Service Set [AS6009] which is platform-agnostic. At present ten (10) services are defined in this document. These services are categorized as:
AS-4JAUS Joint Architecture for Unmanned Systems Committee
One way to decarbonize spark-ignition (SI) engines is to use alternative fuels to improve thermal efficiency. Compressed biomethane gas (CBG), mainly composed of methane and carbon dioxide produced from food waste, has attracted attention as an alternative fuel, but its carbon dioxide content is indeterminate. This study investigates the effects of carbon dioxide content on engine performance (thermal efficiency, etc.), emission characteristics, and turbulent burning velocity using a CBG surrogate fuel mixed with methane and carbon dioxide. A single-cylinder SI engine is used as the test engine, and experiments are conducted under different load conditions with a constant crank angle of 50% mass fraction burned (CA50). Engine performance is analyzed based on heat balance from in-cylinder pressure analysis. Emission characteristics are measured using an emission gas analyzer. Using the boundary conditions obtained from the experiments, parameters such as unstretched laminar burning
Kobayashi, TakumaShimizu, TaketoshiYoshimura, KeiSok, RatnakKusaka, Jin
Ozone (O3) was introduced into the intake air in a natural gas fueled engine ignited by micro-pilot of diesel fuel, to utilize the reactive O-radicals decomposed from the O3 for the promotion of the combustion and for improvements in the thermal efficiency and exhaust emissions. Experiments were carried out in a single cylinder engine to elucidate the effects of the ozone addition under the lean burn conditions. A supercharger was employed to increase the intake air amount and vary the equivalence ratio of natural gas. The experimental results showed that the O3 addition has a limited effect on the ignition of the diesel fuel injected near top dead center, while the heat release during the flame propagation in the natural gas/air mixture was increased at the lower equivalence ratio of natural gas. Further the ignition of natural gas was promoted, resulting in the increase of the combustion efficiency and the degree of constant volume heat release. The cooling loss and the NOx emissions
Kobashi, YoshimitsuMiyata, ShokiKawahara, NobuyukiInagaki, Ryuya
The use of hydrogen as a sustainable fuel in the short term is hampered by the impossibility of large scale use due low availability. In order to promote decarbonization, complementary solution for a smooth transition is to dilute it in a mixture with methane, in a current Port Fuel Injection (PFI) internal combustion engine (ICE). This can be done as a retrofit after limited structural modifications, such as the introduction of a passive prechamber. Such a solution allows a reduction of the carbon footprint of traditional ICEs through more efficient combustion (both the prechamber technology and the hydrogen fuel properties promote an increase in combustion speed) and a reduced carbon content in the fuel. The present research activity has been carried out through numerical investigation based on three-dimensional CFD analyses to simulate the behavior of a natural gas engine fueled with CH4-H2 blends. The combustion mechanism for the fuel blend was validated against measurements of the
Balduzzi, FrancescoFerrara, GiovanniDi Iorio, SilvanaSementa, Paolo
Multiple-ion-probe method consists of multiple ion probes placed on the combustion chamber wall, where each individual ion probe detects flame contact and records the time of contact. From the recorded data, it is also possible to indirectly visualize the inside of the combustion chamber, for example, as a motion animation of moving flame front. In this study, a thirty-two ion probes were used to record flames propagating in a two-stroke gasoline engine. The experiment recorded the combustion state in the engine for about 3 seconds under full load at about 6500 rpm, and about 300 cycles were recorded in one experiment. Twelve experiments were conducted under the same experimental conditions, and a total of 4,164 cycles of signal data were obtained in the twelve experiments. Two types of analysis were performed on this data: statistical analysis and machine learning analysis using a linear regression model. Statistical analysis calculated the average flame detection time and standard
Yatsufusa, TomoakiOkahira, TakehiroNagashige, Kohei
This study aims to investigate the effect of ethanol blends on flame propagation and auto-ignition under high pressure and high temperature conditions. Experimental investigations are conducted using n-C7H16 / ethanol blends at various blending ratios (0, 5, 10, 20, 40, 70, and 100 vol%). The blends are premixed with air at stoichiometric ratios and ignited centrally in a cylindrical constant-volume combustion chamber (20-mm inner diameter, 80-mm long) under elevated temperature (500 K) and pressure (1.0 MPa) conditions. The results show that auto-ignition occurs at an ethanol blend ratio of 10% or less and ceases above 20%. Increasing the ethanol blend to 70% results in a slight change in flame propagation speed, with a noticeable delay at 100%. The pressure measurements show a peak of about 5.6 MPa at a blend ratio of 5%, which gradually decreases with increasing ratios. High-pass filtering reveals the maximum pressure fluctuation amplitude at the 5% blend ratio, indicating increased
Tateishi, TokuaYamaguchi, RikiShimokuri, DaisukeTerashima, HiroshiHara, TakayaHonda, YuyaKawano, Michiharu
Flex fuel vehicles (FFV) can operate effectively from E5 (Gasoline 95%, ethanol 5%) fuel to E100 (Gasoline 0%, ethanol 100%) fuel. It is necessary to meet the performance, drivability, emission targets and regulatory requirements irrespective of fuel mixture combination. This research work focuses on optimizing the combustion efficiency and conversion efficiency of catalytic converter of a spark-ignited less than 200 cc engine for FFV using Taguchi methods robust optimization technique. The study employs an eight-step robust optimization approach to simultaneously minimize engine out emissions and maximize catalytic converter efficiency. Six control factors including type of fuel, catalyst heating rpm, lambda (excess-air ratio), injection end angle, lambda controller delay, and ignition timing are optimized. Four noise factors like compression ratio, clearance volume, catalyst noble metal loading, and catalyst aging are also considered. Through approximately 100 physical experiments on
Vaidyanathan, BalajiArunkumar, PraveenkumarShunmugasundaram, PalaniMurugesan, ManickamJayajothijohnson, Vedhanayagam
The relation between the multiple auto-ignition in the premixed charge with fuel concentration distribution and associated pressure wave are numerically investigated. This study assumes that the auto-ignition phenomenon in the end-gas of PCCI combustion, a next-generation combustion method which is expected to achieve both low fuel consumption and low emissions at a high level. Detailed numerical analysis considering the elementary chemical reactions of the compressible reacting fluid flow described in the one-dimensional coordinate system with high spatial and time resolution was performed to clarify the detailed phenomena of the onset of the multiple auto-ignition and the pressure wave propagation in the gas.
Iizumi, KotaYoshida, Kenji
In order to rapidly achieve the goal of global net-zero carbon emissions, ammonia (NH3) has been deemed as a potential alternative fuel, and reforming partial ammonia to hydrogen using engine exhaust waste heat is a promising technology which can improve the combustion performance and reduce the emission of ammonia-fueled engines. However, so far, comprehensive research on the correlation between the reforming characteristic for accessible engineering applications of ammonia catalytic decomposition is not abundant. Moreover, relevant experimental studies are far from sufficient. In this paper, we conducted the experiments of catalytic decomposition of ammonia into hydrogen based on a fixed-bed reactor with Ru-Al2O3 catalysts to study the effects of reaction temperature, gas hour space velocity (GHSV) and reaction pressure on the decomposition characteristics. At the same time, energy flow analysis was carried out to explore the effects of various reaction conditions on system
Li, ZeLi, TieChen, RunLi, ShiyanZhou, XinyiWang, Ning
In this experiment, we investigated the auto-ignition and flame propagation behavior by using flat piston and cavity pistons which has different geometries, depth, and width of the cavity. In this study, flame behavior inside the cavity is visualized with the ion-probes, which is embedded every 3mm radially from the center of the piston. We also used the pressure sensor in the combustion chamber and high-speed camera through the quartz window near the cylinder wall. Flame appearance obtained with high-speed camera shows that the flame propagation of the cavity piston is faster than that of flat piston. This is considered because of the outward induced flow in the squish area. That is, the flame propagation inside the wide cavity area pushes the unburned gas outwardly and induced the outward flow in the squish area. This induced flow promotes the flame propagation. As a result, unburned gas is consumed rapidly, and thus, it is also found that the intensity of Knocking is reduced by
Yamaguchi, RikiEsaki, DaigoTateishi, TokuaOsaf, Ali HassanMiyoshi, AkiraShimokuri, DaisukeYatsufusa, TomoakiTerashima, HiroshiHara, TakayaHonda, YuyaTadokoro, TadashiKawano, Michiharu
Hybrid powertrain for motorcycles has not been widely adopted to date but has recently shown significant increased interest and it is believed to have great potential for fuel economy containment in real driving conditions. Moreover, this technology is suitable for the expected new legislations, reduced emissions and enables riding in Zero Emissions Zones, so towards a more carbon neutral society while still guaranteeing “motorcycle passion” for the product [1, 2]. Several simulation tools and methods are available for the concept phase of the hybrid system design, allowing definition of the hybrid components and the basic hybrid strategies, but they are not able to properly represent the real on-road behaviour of the hybrid vehicle and its specific control system, making the fine tuning and validation work very difficult. Motorcycle riders are used to expect instant significant torque delivery on their demand, that is not properly represented in legislative cycles (e.g. WMTC); rider
Antoniutti, ChristianSweet, DavidHounsham, Sandra
As the automotive sector shifts towards cleaner and more sustainable technologies, fuel cells and batteries have emerged as promising technologies with revolutionary potential. Hydrogen fuel cell vehicles offer faster refueling times, extended driving ranges, and reduced weight and space requirements compared to battery electric vehicles, making them highly appealing for future transportation applications. Despite these advantages, optimizing electrode structures and balancing various transport mechanisms are crucial for improving PEFCs’ performance for widespread commercial viability. Previous research has utilized topology optimization (TO) to identify optimal electrode structures and attempted to establish a connection between entropy generation and topographically optimized structures, aiming to strengthen TO numerical findings with a robust theoretical basis. However, existing studies have often neglected the coupling of transport phenomena. Typically, it is assumed that a single
Tep, Rotanak Visal SokLong, MenglyAlizadeh, MehrzadCharoen-amornkitt, PatcharawatSuzuki, TakahiroTsushima, Shohji
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