International Journal of Alternative Propulsion最新文献

{"title":"Instantaneous, two-dimensional, spontaneous Raman measurements of hydrogen number density in a laminar jet using an intra-cavity configuration","authors":"D. Kyritsis, P. Felton, F. Bracco","doi":"10.1504/IJAP.2007.013021","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013021","url":null,"abstract":"In view of the increasing importance of hydrogen as a fuel, we are presenting a novel experimental technique that allows for two-dimensional (2D), spontaneous Raman hydrogen concentration measurements in optically accessible enclosures. The novelty of the technique lies in that the actual experiment takes place in a laser cavity, which significantly enhances the inherently weak hydrogen Raman signal. Quantitative, 2D measurements of hydrogen number density were performed at elevated pressure by inserting a pressurised vessel in the cavity of a flashlamp-pumped dye laser. Particular emphasis is placed on the determination of the data accuracy of this technique, which is inherently noisy because of the weakness of the Raman signal. The measurements are compared with the results of direct numerical simulation for a laminar jet. The problems of determining accurately the position and the intensity profile of the laser sheet are addressed. A minimum number density of hydrogen that can be detected with an acceptable signal-to-noise ratio, for a 520-m resolution, was determined.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131343622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of available exhaust gas heat recovery technologies for HD diesel engine applications","authors":"D. Hountalas, C. Katsanos, D. A. Kouremenos, E. Rogdakis","doi":"10.1504/IJAP.2007.013019","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013019","url":null,"abstract":"Diesel engines reject a considerable amount of energy to the ambience through the exhaust gas. Significant reduction of engine brake-specific fuel consumption (bsfc) could be attained by recovering a significant part of exhaust gas heat. Various techniques have been proposed in the past to recover exhaust energy: mechanical, electrical turbocompounding and Rankine Bottoming Cycles. In the present it is examined the potential bsfc improvement of heavy-duty (HD) diesel engines using the aforementioned technologies. The analysis is performed on a HD Diesel engine. An engine simulation model is used to estimate exhaust gas characteristics and examine mechanical and electrical turbocompounding. For mechanical turbocompounding it is investigated the effect of power turbine pressure ratio and efficiency while for electric the effect of T/C efficiency and exhaust pressure increase. Finally, a parametric study has been conducted using a 'Rankine bottoming cycle'. The analysis includes the effect of evaporator pressure and expander efficiency.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128279821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of temperature gradients through local extinction using Raman scattering spectroscopy","authors":"W. Carnell, M. Renfro","doi":"10.1504/IJAP.2007.013017","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013017","url":null,"abstract":"Measurements of temperature in laminar flames with localised extinction points were made using line imaging of spectrally resolved laser Raman scattering through the extinction process. A fit to the nitrogen scattering spectrum was used to determine temperature with an accuracy of 30 K. Temperature gradients through the extinction process were measured as the flame strength prior to extinction and the rate of extinction was separately controlled. The results were compared to previously reported numerical simulations for this flame and were found to validate the modelling of the flame extinction process. The measured temperature gradient is affected by the radial rate at which strain is increased, as well as inner flame strength. Measurements of integrated flame emission were also made at the extinction point and indicate that reactions persist at temperatures well below the onedimensional extinction temperature, which is consistent with reaction rate profiles from the numerical simulations.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126486840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the performance and emissions of a high-speed direct injection diesel engine operating on ethanol diesel fuel blends","authors":"C. Rakopoulos, K. A. Antonopoulos, D. Rakopoulos, D. Hountalas, E. C. Andritsakis","doi":"10.1504/IJAP.2007.013020","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013020","url":null,"abstract":"An experimental study is conducted to evaluate the effects of using various blends of ethanol with normal diesel fuel, in blend ratios of 5/95, 10/90 and 15/85, on the performance and exhaust emissions of a high-speed, direct injection (DI), Ricardo/Cussons 'Hydra' diesel engine. The tests are conducted using each of the above fuel blends or neat diesel fuel. Volumetric fuel consumption, exhaust gas temperature, exhaust smokiness and exhaust regulated gas emissions such as nitrogen oxides, carbon monoxide and total unburned hydrocarbons are measured. The differences in the performance and exhaust emission parameters from the baseline operation of the engine, that is, when working with neat diesel fuel, are determined and compared. Theoretical aspects of diesel engine combustion are used to aid the interpretation of the engine behaviour.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"56 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114052976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and characterisation of small-scale rotary engines","authors":"S. Sprague, Sangwon Park, D. Walther, A. Pisano, A. Pello","doi":"10.1504/IJAP.2007.013016","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013016","url":null,"abstract":"This paper describes the development and characterisation of small-scale rotary engines with displacements in the range of 781500 mm for portable applications in the range of 10200 W of power output. Small-scale combustion engines present a number of research challenges including manufacturing tolerances, sealing, thermal management, ignition, combustion efficiency and porting. Four engines have been characterised using a custom test bench and show an increase in performance due to design changes that mitigate the challenges associated with small-scale engines. The volumetric power density has been increased from 11 W/cm in a 348 mm engine operating with a supercharged hydrogen/air mixture to 22 W/cm in a 1500 mm engine operating with naturally aspirated liquid hydrocarbon fuel. The thermal efficiency has also been increased from 0.2 to 4%. Continued improvements in sealing, thermal management, combustion efficiency and friction reduction will allow further increases in engine performance.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115444789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding methane flame kinetics from reduced mechanisms","authors":"G. Skevis, D. Goussis, E. Mastorakos","doi":"10.1504/IJAP.2007.013025","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013025","url":null,"abstract":"Reduced mechanisms for laminar premixed methaneair flames are constructed on the basis of the GRI-3.0 detailed chemistry. It is demonstrated that significant understanding of the flame chemistry can be acquired by examining reduced mechanisms generated on the basis of either the full flame domain or specific subdomains, such as the preheat, the flame and the post-flame zones. Reduced mechanisms of increasing number of steps generated by taking into account the full flame domain identify the parts of chemistry that relate to the slowest chemical time scales and thus dominate the overall flame structure. Observed differences in the reduced mechanisms of a given size generated on the basis of different regions of the flame distinguish the locally prevailing kinetic paths. The effects of inlet mixture composition on the dominant parts of chemistry are discussed.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117340517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intermediate Reynolds/Peclet number, flat plate boundary layer flows over catalytic surfaces for micro-combustion applications","authors":"S. Smyth, Kowtilya Bijjula, D. Kyritsis","doi":"10.1504/IJAP.2007.013026","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013026","url":null,"abstract":"The reactive, flat plate boundary layer flow of close-tostoichiometric, methaneair mixtures over small size Pt plates is studied experimentally for intermediate Reynolds and Peclet numbers which pertain to micro-combustion applications. The surface temperature was measured with infrared thermography and correlated to reactant concentration profiles acquired with line-Raman imaging. Three phases of combustion were observed. Immediately after the leading edge, a first phase was established with a high surface temperature (>1200C) and intense fuel depletion. The Reynolds number and equivalence ratio strongly influenced this first phase. It was followed by a second, longer phase, where temperature reached an intermediate value near 1000C that exhibited little sensitivity to Reynolds number and equivalence ratio. In a third phase, combustion was completed and the surface temperature was reduced to the free-stream mixture temperature. It is suggested that this 'Phase I' combustion can be used for burner miniatu...","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133884665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the performance and exhaust emissions of a spark-ignited engine operating on syngas fuel","authors":"R. G. Papagiannakis, C. Rakopoulos, D. Hountalas, E. G. Giakoumis","doi":"10.1504/IJAP.2007.013022","DOIUrl":"https://doi.org/10.1504/IJAP.2007.013022","url":null,"abstract":"To resolve the problem of depletion of petroleum based liquid fuels, various solutions have been proposed. One of them is the use of gaseous fuels that are generated from the gasification of woods, namely syngas or wood-gas fuels, as full supplement fuels in spark ignition internal combustion (IC) engines. This fuel consists of nearly 40% combustible gases, mainly hydrogen and carbon monoxide (CO), while the rest is non-combustible gases. In the present work, a comparison between experimental and computed results is presented for a conventional natural gas, spark-ignited engine, fuelled with syngas instead of natural gas fuel. For the theoretical investigation, a computer model is developed that simulates the syngas combustion processes in a conventional natural gas, spark-ignited engine. The combustion model is a two-zone one, where the combustion rate of syngas fuel depends on the velocity of the flame front that forms around the area of the burning zone and then spreads inside the combustion chamber. The flame front development takes into account the history of pressure and temperature inside the chamber and the local composition, in order to estimate the flame velocity. An equilibrium model is used to determine the concentration of the chemical species involved, the extended Zeldovich mechanism is used to determine the concentration of nitric oxide (NO) and a CO kinetics scheme is used to estimate the CO emission. To validate the predictive ability of the model, experimental measurements are used from the operation of a multi-cylinder, four-stroke, turbocharged, spark-ignited engine fuelled with syngas fuel, with the measurements corresponding to various values of the air to fuel ratio (load). The experimental results are found to be in good agreement with the respective computed ones obtained from the computer model. Comparing the computed results when operating the engine with natural gas as against syngas fuel, a serious effect of the syngas operation on the cylinder pressure diagrams and the engine brake efficiency is revealed, for all test cases examined. Moreover, as far as pollutant emissions are concerned, the use of natural gas instead of syngas has a positive effect on both NO and CO emissions (reduction).","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132302777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved driveability of a hybrid electric vehicle using powertrain control","authors":"J. Fredriksson","doi":"10.1504/IJAP.2006.010760","DOIUrl":"https://doi.org/10.1504/IJAP.2006.010760","url":null,"abstract":"Hybridisation of vehicles is not only equivalent to improved energy efficiency and reduced emissions. In this paper, the additional degree-of-freedom introduced by electrifying the propulsion system of a vehicle is used for improving driveability. The vehicle in focus is a truck with an electric machine integrated into the engine's flywheel, a so-called integrated starter–alternator, that is, a vehicle with a low level of hybridisation. The electric machine is used to assist the internal combustion engine during transients. The idea is to use the internal combustion engine in combination with the electric machine to actively damp out oscillations induced in the driveline during acceleration. This paper includes driveline modelling, control design and verifications by simulations. The simulation shows that the use of powertrain control for a mild hybrid parallel powertrain configuration works very well. Not only can the driveability of the vehicle be improved it also reduces the emissions and is energy efficient.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125625522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of genetic algorithm for simultaneous optimisation of HEV component sizing and control strategy","authors":"M. Montazeri-Gh, Amir Poursamad","doi":"10.1504/IJAP.2006.010758","DOIUrl":"https://doi.org/10.1504/IJAP.2006.010758","url":null,"abstract":"This paper describes a methodological approach for the simultaneous optimisation of Hybrid Electric Vehicle (HEV) component sizing and control strategy using Genetic Algorithm (GA). In this approach, using a parallel HEV configuration and an Electric Assist Control Strategy (EACS), the optimisation problem is formulated. The whole set of sizing and control variables is then encoded as the chromosomes. The multi-objective target is also defined to minimise the Fuel Consumption (FC) and emissions. In addition, the PNGV performance requirements are considered as constraints. Finally, to evaluate the objective function, three driving cycles, ECE-EUDC, FTP and TEH-CAR, are employed. The simulation results obtained in this study show that the approach is effective, resulting in improvement of the objective value and FC.","PeriodicalId":425490,"journal":{"name":"International Journal of Alternative Propulsion","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130045377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}