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Christoffersen L.,Chalmers University of Technology | Soderblom D.,Chalmers University of Technology | Lofdahl L.,Chalmers University of Technology | Hill R.,Lotus Engineering | Kerr L.,Lotus Cars
SAE Technical Papers

Amongst the aerodynamic devices often found on race cars, the diffuser is one of the most important items. The diffuser can work both to reduce drag and also to increase downforce. It has been shown in previously published studies, that the efficiency of the diffuser is a function of the diffuser angle, ground clearance and most importantly, the base pressure. The base pressure of a car is defined by the shape of the car and in particular the shape at the rear end, including the rear wheels. Furthermore, on most race cars, a wing is mounted at the rear end. Since the rear wheels and wing will influence the base pressure it is believed that, for a modern race car, there could be a strong interaction between these items and the diffuser. This work aims to systematically study the interaction between the rear wheels and wing; and the diffuser of a contemporary, sports car type, race vehicle. The work was carried out using computational fluid dynamics and the geometry, that the study was based on, was the Lotus Evora Type 124 CUP car. The car carried detailed chassis components and a complete cooling system. In the study, the diffuser angle was varied over several inclinations, ranging from 3 to 12 degrees. Furthermore, the height of the wing over the "rear deck" of the car was also varied. It was found from the study that the vertical position of the wing over the rear deck of the car had no significant influence on the flow through the diffuser, at the wing heights tested and vice versa, the diffuser showed only little influence on the flow past the rear wing. The diffuser however, had an influence on the base pressure and most importantly; on the downforce generation. At increasing diffuser angles the base pressure was reduced and consequently the downforce was increased. Copyright © 2011 SAE International. Source

Crawled News Article
Site: http://cleantechnica.com

As we reported recently, the first electric car recently rolled off the production lines at Detroit Electric’s manufacturing facility in the UK, bringing the anticipated electric sports car one step closer to wide release. As many have no doubt predicted — following the company’s scrapping of plans for production in the car manufacturing hub of Detroit, Michigan… from which Detroit Electric gets its name — it seems that the company may well end up not releasing the new electric vehicle (EV) in the US at all…. The name appears to (possibly) just be a means of selling Americana to Europeans (as with cowboys, country/honky tonk, blues music, jazz, etc). Even though the first SP:01 has rolled off the line and been sent on its way to an unidentified buyer in an unidentified location, the company (which is headquartered in The Netherlands, by the way) has yet to announce the car’s retail price. One thing is certain, though: the figure won’t be in American dollars. Despite its name, a nod to a defunct US-based maker of electric carriages from 1907 to 1938, the Detroit Electric sports car won’t be available in Detroit — or anywhere else in America. The company plans to sell the SP:01 only in Europe, Asia and few other select markets, including Iceland and South Africa. Detroit Electric’s CEO, Albert Lam, who announced the SP:01 with stars-and-stripes-waving enthusiasm back in 2013, doesn’t take the company’s geographic incongruity lightly. “We are Detroit Electric, not London Electric,” said Lam, former CEO of the Lotus Engineering Group. “Our commitment to the city of Detroit, the state of Michigan and the United States is as strong as it ever was.” But as the saying goes, love is a verb, and whether Lam can turn affectionate words into action remains to be seen. The company has promised that if things go well for its UK-built sports car, it will open a production facility in its namesake city to build a clean-sheet electric sedan. You can count me as skeptical that the Detroit Electric SP:01 will ever actually be available for general purchase in Detroit. Oh well, at least we still have Tesla to showcase the (seemingly asleep) “American entrepreneurial spirit.” And, yes, I’m aware that CEO Elon Musk is South African.     Get CleanTechnica’s 1st (completely free) electric car report → “Electric Cars: What Early Adopters & First Followers Want.”   Come attend CleanTechnica’s 1st “Cleantech Revolution Tour” event → in Berlin, Germany, April 9–10.   Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.   James Ayre 's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.

Turner J.W.G.,Lotus Engineering | Pearson R.J.,Lotus Engineering | McGregor M.A.,Lotus Engineering | Ramsay J.M.,Lotus Engineering | And 5 more authors.
SAE Technical Papers

The paper presents vehicle-based test work using tri-component, or ternary, blends of gasoline, ethanol and methanol for which the stoichiometric air-fuel ratio (AFR) was controlled to be 9.7:1. This is the same as that of conventional 'E85' alcohol-based fuel. Such ternary blends are termed 'GEM' after the first initial of the three components. The present work was a continuation of an earlier successful project which established that the blends were effectively invisible to a car using a virtual alcohol sensor. The vehicle used here employed the other major technology in flex-fuel vehicles to determine the proportion of alcohol fuel in the tank, a physical alcohol sensor. Another aspect of the present work included the desire to investigate ternary blend replacements for E85 having low ethanol concentrations. Evidence from the previous work suggested that under specific conditions, ethanol was required in some amount to act as a cosolvent for the gasoline and methanol in the blend. The present paper discusses the position of the phase separation boundary with respect to the concentration of the individual components, and determines new blends for test which are closer to this boundary. These and other ternary blends were first tested on the road and in a cold chamber, where cold startability was gauged at-20°C. All of the ternary blends were found to start well except that corresponding to E85, which would not start at all at this low temperature using this summer grade fuel. Of the fuel blends tested in the first phase, four were selected for more-controlled investigation in an emissions laboratory. Each was tested twice on the NEDC cycle under cold and hot conditions. In addition, gasoline baseline tests (using the same procedure) were conducted at the start and end of the ternary blend tests. The ternary blends were invisible to the vehicle, with no malfunction indicator light activity at all. An estimate of the cost of one of the blends (containing 10% by volume ethanol), based on current individual costs of the individual components, is made to be 10.1% cheaper than gasoline, on an energy basis. Finally, there is a discussion of how renewable methanol can be introduced, aided by the ability of the existing flex-fuel vehicle fleet to accept these fuel blends, and also of a means of manufacturing such fully-sustainable methanol by a coupling of the electricity and gas grids to enable massive storage of renewable energy. Copyright © 2012 Lotus Cars Limited. Source

Pearson R.J.,Lotus Engineering | Eisaman M.D.,Palo Alto Research Center PARC | Eisaman M.D.,Brookhaven National Laboratory | Turner J.W.G.,Lotus Engineering | And 7 more authors.
Proceedings of the IEEE

Fossil fuels are renewable only over geological time scales. The oxidation, via combustion, of considerable amounts of carbonaceous fuels since the dawn of the industrial revolution has led to a rapid accumulation of CO 2 in the atmosphere leading to an anthropogenic influence on the Earth's climate. We highlight here that a versatile energy carrier can be produced by recycling CO 2 and combining it chemically with a substance of high chemical bond energy created from renewable energy. If CO 2 is taken from the atmosphere, a closed-loop production process for carbon-neutral fuels is possible providing an energy-dense and easily distributed storage medium for renewable energy. The rationale for reduced carbon or carbon-neutral energy carriers made from recycled CO $ 2 is described, focusing on, for transport applications, their manifestation as energy-dense carbonaceous liquid fuels. Techniques for the separation of CO 2 directly from the atmosphere are reviewed, and the challenges and advantages relative to flue-gas capture are discussed. Pathways for the production of carbonaceous fuels from CO 2 are discussed. An integrated system is proposed where renewable energy is stored in the form of synthetic methane in the gas grid for supply to the power generation and heat sectors while methanol and drop-in hydrocarbon fuels are supplied to the transport sector. The use of atmospheric CO 2 and water as feed stocks for renewable energy carriers raises the important prospect of alleviating a dependency on imported fossil energy with the associated large financial transfers. Their application in the transport sector yields a high-value end product. The synthesis and storage of carbon-neutral liquid fuels offers the possibility of decarbonizing transport without the paradigm shifts required by either electrification of the vehicle fleet or conversion to a hydrogen economy.They can be supplied either as drop-in hydrocarbon fuels for existing reciprocating and turbine-powered combustion engines or, at lower energetic cost and using simpler chemical plant, in the form of low-carbon-number alcohols which can be burned at high efficiency levels in optimized internal combustion engines. The suitability of these fuels for conventional engines enables the continued provision of globally compatible, affordable vehicles. © 2006 IEEE. Source

Zhao H.,Brunel University | Psanis C.,Brunel University | Ma T.,Brunel University | Turner J.,Lotus Engineering | Pearson R.,Lotus Engineering
International Journal of Engine Research

As an alternative to the electric hybrid powertrain, air-hybrid engine concepts have the potential to achieve regenerative braking and air-assisted engine operations for low-carbon vehicle applications. Over the last few years, systematic studies have been carried out by the authors on a number of air-hybrid engine concepts. This paper presents the modelling and experimental results of air-hybrid engine operation enabled by fully variable valve actuation (FVVA). The principle and key operating features of such an air-hybrid engine will be presented first. This is followed by a detailed theoretical analysis of the two-stroke compression and expansion operations enabled by the FVVA system. Finally, experimental results will be presented with regard to the actual performance of a single-cylinder engine operating in the compression mode and expansion mode through the Lotus active valve train system. copyright © 2012 by institution of mechanical engineers. Source

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