Search results for "Spark"
showing 10 items of 124 documents
A New Simple Friction Model for S. I. Engine
2009
Internal combustion engine modeling is nowadays a widely employed tool for modern engine development. Zero and mono dimensional models of the intake and exhaust systems, combined with multi-zone combustion models, proved to be reliable enough for the accurate evaluation of in-cylinder pressure, which in turn allow the estimation of the engine performance in terms of indicated mean effective pressure (IMEP). In order to evaluate the net engine output, both the torque dissipation due to friction and the energy drawn by accessories must be taken into consideration, hence a model for the friction mean effective pressure (FMEP) evaluation is needed. One of the most used models accounts for engin…
Knock Resistance Increase through the Addition of Natural Gas or LPG to Gasoline: An Experimental Study
2013
Bi-fuel spark ignition engines, nowadays widely spread, are usually equipped with two independent injection systems, in order run the engine either with gasoline or with gaseous fuel, which can be Natural Gas (NG) or Liquefied Petroleum Gas (LPG). These gases, besides lower cost and environmental impact, are also characterized by a higher knock resistance with respect to gasoline that allows to adopt a stoichiometric proportion with air also at full load. Gasoline, on the other hand, being injected as liquid, maintains higher volumetric efficiency and hence higher power output. As a compromise solution, it could be desired to exploit the advantages of both gasoline and gas (NG or LPG), thus…
InspirationWall
2015
Collaborative idea generation leverages social interactions and knowledge sharing to spark diverse associations and produce creative ideas. Information exploration systems expand the current context by suggesting novel but related concepts. In this paper we introduce InspirationWall, an unobtrusive display that leverages speech recognition and information exploration to enhance an ongoing idea generation session with automatically retrieved concepts that relate to the conversation. We evaluated the system in six idea generation sessions of 20 minutes with small groups of two people. Preliminary results suggest that InspirationWall contrasts the decay of idea productivity over time and can t…
Performance Prevision of a Turbocharged Natural Gas Fuelled S.I. Engine
2008
Natural gas represents today maybe the most valid alternative to conventional fuels for road vehicles propulsion. The main constituent of natural gas, methane, is characterized by a high autoignition temperature, which makes the fuel highly resistant to knocking: this allows a considerable downsizing of the engine by means of supercharging even under high compression ratio. Starting from these considerations, the authors realized a thermodynamic model of a 4-cilynder s.i. engine for the prevision of in-cylinder pressure, employing a two-zone approach for the combustion and adding sub-models to account for gas properties change and knocking occurrence. An extensive experimental campaign has …
Detailed Combustion Analysis of a Supercharged Double-Fueled Spark Ignition Engine
2021
The main goal of researches in the field of automotive engineering is to obtain a large-scale implementation of low- or zero-emissions vehicles in order to substantially reduce air pollution in urban areas. A fundamental step toward this green transition is represented by the improvement of current internal combustion (IC) engines in terms of fuel economy and pollutant emissions. The spark ignition (SI) engines of modern light-duty vehicles are supercharged, down-sized, and equipped with direct injection. Gaseous fuels, such as liquefied petroleum gas (LPG) or natural gas (NG), proved to be a valid alternative to gasoline in order to reduce pollutant emissions and increase fuel economy. In …
Performances and Emissions Improvement of an S.I. Engine Fuelled by LPG/Gasoline Mixtures
2010
As is known gaseous fuels, such as Liquefied Petroleum Gas (LPG) and Natural Gas (NG), thanks to their good mixing capabilities, allow complete and cleaner combustion than normal gasoline, resulting in lower pollutant emissions and particulate matter. Some of the automobile producers already put on the market “bi-fuel” engines, which may be fed either with standard gasoline or with LPG. These engines, endowed of two separate injection systems, are originally designed for gasoline operation; hence they do not fully exploit the good qualities of LPG, such as its better knocking resistance, which would allow higher compression ratios. Moreover, when running with gasoline at medium high loads, …
Augstas veiktspējas datu integrācija
2022
Datu apmaiņa starp sistēmām jeb datu integrācija ir ļoti svarīga datu pārvaldības procesa sastāvdaļa. Katru dienu tiek izveidots, nodots un apstrādāts milzīgs apjoms ar datiem, tāpēc, attīstoties tehnoloģijām un parādoties jauniem risinājumiem, ir iespējams padarīt datu integrācijas procesus kvalitatīvākus, ātrākus un efektīvākus. Darba mērķis ir apskatīt un izpētīt apjomīgu un ar sarežģītu struktūru datu integrācijas risinājumus, veikt metožu un rīku salīdzinājumus un atrast piemērotu risinājumu gan uzņēmumā jau esošo datu apmaiņu uzlabošanai, gan jaunu datu integrāciju izstrādei. Lai sasniegtu mērķi, tika izpētīta literatūra par datu izmaiņu uztveršanu, datu apstrādi, datu noliktavām un N…
Sustainable sparkling base wines obtained from waste matrices of the wine and honey supply chain
2019
The present work was performed to improve the general quality characteristics of sparkling wines produced in Southern Italy (Sicily region) as well as the sustainability of the production process. To this purpose, two novel approaches were applied during experimental winemaking: (i), the use of raceme grapes (formed from the secondary shoots) of Grillo cultivar to improve the chemical characteristics of sparkling base wine; (ii), the technological selection of potential fructophilic Saccharomyces cerevisiae strains isolated from honey by-product to improve the alcoholic fermentations and the organoleptic features of bottled wines. The racemes are typical of Grillo cugrapes and mature 20 day…
Immobilised Cell Technology in Winery and Fruit Wine Production
2006
Winemaking is largely concerned with the progress of biotechnology and especially with the use of high cell density reactors. Entrapment is the most widely method to immobilise cells; several matrix can be used (alginate, carrageenan, agar) with different geometry (beads, fibres, plates). Alcoholic fermentation of wine, malolactic fermentation, bottle fermentation known as the "Methode champenoise" and sparkling wines are among the industrial applications. Whereas prospects for this technology appear encouraging, further research is needed to optimise reaction variables, improve the long-term stability of the reactors, and understand more about secondary metabolite production by yeasts unde…
Effect of Production Phase on Bottle-Fermented Sparkling Wine Quality
2015
This review analyzes bottle-fermented sparkling wine research at each stage of production by evaluating existing knowledge to identify areas that require future investigation. With the growing importance of enological investigation being focused on the needs of the wine production industry, this review examines current research at each stage of bottle-fermented sparkling wine production. Production phases analyzed in this review include pressing, juice adjustments, malolactic fermentation (MLF), stabilization, clarification, tirage, lees aging, disgorging, and dosage. The aim of this review is to identify enological factors that affect bottle-fermented sparkling wine quality, predominantly …