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Viewing 1 to 13 of 13
2015-04-14
Technical Paper
2015-01-0304
Samveg Saxena, Jason MacDonald, Doug Black, Sila Kiliccote
Abstract Electric vehicles (EVs) enable improved vehicle efficiency and zero emissions in population centers, however the large loads from EV charging can stress grid systems during periods of peak demand. We apply detailed physics-based models of EVs with data on how drivers use their cars to quantify the ability for EVs to reduce their charging during periods of peak demand, i.e. as in a demand response program. A managed charging controller is developed and applied within the vehicle-to-grid simulator (V2G-Sim) which charges vehicles during demand response (DR) events only if charging is required to satisfy anticipated mobility needs for a given driver over the next 24 hours. We find that up to 95% of EV charging loads can be removed during DR events without compromising the mobility needs of individual drivers. This value is found by comparing the charging loads of EVs using the managed charging controller against an uncontrolled charging case.
2015-04-14
Technical Paper
2015-01-0821
Alvaro Pinheiro, David Vuilleumier, Darko Kozarac, Samveg Saxena
Abstract This paper follows a cycle-simulation method for creating an engine performance map for an ethanol fueled boosted HCCI engine using a 1-dimensional engine model. Based on experimentally determined limits, the study defined operating conditions for the engine and performed a limited parameter sweep to determine the best efficiency case for each condition. The map is created using a 6-Zone HCCI combustion model coupled with a detailed chemical kinetic reaction mechanism for ethanol, and validated against engine data collected from a 1.9L 4-Cylinder VW TDI engine modified to operate in HCCI mode. The engine was mapped between engine speeds of 900 and 3000 rpm, 1 and 3 bar intake pressure, and 0.2 and 0.4 equivalence ratio, resulting in loads between idle and 14.0 bar BMEP. Analysis of a number of trends for this specific engine map are presented, such as efficiency trends, effects of combustion phasing, intake temperature, engine load, engine speed, and operating strategy.
2012-04-16
Technical Paper
2012-01-1119
Ivan Dario Bedoya, Francisco Cadavid, Samveg Saxena, Robert Dibble, Salvador Aceves, Daniel Flowers
This study presents the development of a new HCCI simulation methodology. The proposed method is based on the sequential coupling of CFD analysis prior to autoignition, followed by multi-zone chemical kinetics analysis of the combustion process during the closed valve period. The methodology is divided into three steps: 1) a 1-zone chemical kinetic model (Chemkin Pro) is used to determine either the intake conditions at IVC to achieve a desired ignition timing or the ignition timing corresponding with given IVC conditions, 2) the ignition timing and IVC conditions are used as input parameters in a CFD model (Fluent 6.3) to calculate the charge temperature profile and mass distribution prior to autoignition, and 3) the temperature profile and mass distribution are fed into a multi-zone chemical kinetic model (Chemkin Pro) to determine the main combustion characteristics.
2006-04-03
Technical Paper
2006-01-0829
Joseph C. Ghislain, Aimee T. McKane
Industrial motor-driven systems consume more than 70% of global manufacturing electricity annually and offer one of the largest opportunities for energy savings. System optimization techniques through the application of existing, commercially available technologies and accepted engineering practices typically achieve energy savings of 20% or more for these systems across all industrial sectors. The optimization opportunities for steam systems are at least equal or greater. Despite the potential benefits, energy savings from these industrial systems have remained largely unrealized by US industry. This paper presents the argument that unless energy efficiency is institutionalized, it will be viewed by corporate managers as something different than the effective and efficient use of labor and material resources. If this institutionalization does not occur, the potential benefits will never be achieved or sustained.
2004-07-19
Technical Paper
2004-01-2280
L. Heilbronn, S. Guetersloh, J. Miller, C. Zeitlin
This report describes the highlights and progress made in a program of measurements studying radiation transport through materials of interest to NASA. All measurements were performed at accelerator facilities, primarily using GCR-like heavy-ion beams incident upon various elemental and composite targets. Both primary and secondary particles exiting the target were measured. The secondary particles include both charged particles and neutrons. These measurements serve as useful benchmarks and input to transport model calculations.
2003-07-07
Technical Paper
2003-01-2330
J. Ware, J. Ferl, J. W. Wilson, M. S. Clowdsley, G. De Angelis, J. Tweed, C. J. Zeitlin, J. Miller, L. H. Heilbronn
Prior studies have been performed where basic fabric lay-ups of the current Shuttle spacesuit were tested for radiation shielding capabilities. It was found that the fabric portions of the suit give far less protection from radiation than previously estimated. This is due to the porosity and non-uniformity of the fabrics and LCVG components. These findings were incorporated into the spacesuit model developed at NASA Langley Research Center to estimate exposures for mission planning and evaluation of safety during radiation field disturbance. Overall material transmission properties were also less than optimal. In order to evaluate the radiation protection characteristics of some proposed new spacesuit materials, fifteen test target combinations of current baseline and new proposed spacesuit materials were exposed to a low-energy proton beam at Lawrence Berkeley National Laboratory. Each target combination contained all of the necessary spacesuit layers, i.e.
2003-03-03
Technical Paper
2003-01-1076
Daniel Türler, Deborah Hopkins, Howdy Goudey
Advanced lightweight insulation and window technologies can contribute significantly to achieving industry and government goals of substantially improving fuel economy without loss of vehicle performance or passenger comfort. Two conventional passenger automobiles, a 2001 sport-utility vehicle (SUV) and a 1999 mid-size sedan, were retrofitted with lightweight insulation; the sedan was also fitted with specially designed windows. The body insulation and windows reduce heating and cooling loads, which allows downsizing of heating, ventilation, and air conditioning (HVAC) equipment. Benefits derived from the use of advanced insulation and window technologies include: Demonstrated reductions in cooling loads; Fuel savings for conventional and hybrid vehicles; Extended range for electric vehicles; Greatly improved passenger comfort; Reduced degradation of interior surfaces; and Improved safety.
2003-03-03
Technical Paper
2003-01-0980
Daniel Türler, Deborah Hopkins, Frédéric Reverdy
A series of laboratory experiments were conducted to determine the ability of acoustic and thermographic methods to evaluate the quality of individual spot welds and the structural integrity of spot-welded joints with and without adhesive. Test specimens consisted of spot-welded, adhesive-bonded, and weld-bonded lap joints in steel plates. The quality of the spot welds was altered by varying welding parameters. After nondestructive evaluation, the samples were peeled or subjected to mechanical tests to determine the strength of the welds. Results demonstrate that it is possible to detect defective spot welds in both the thermographic and acoustic images. Techniques are presented that allow identification of “stick” welds characterized by solid but weak contact. Methods to quantify the imaging results are being developed by comparing the acoustic and thermographic images to the data obtained from mechanical strength tests and modeling results.
2002-07-15
Technical Paper
2002-01-2462
J. Ware, J. Ferl, J. W. Wilson, M. S. Clowdsley, G. de Angelis, J. Tweed, C. J. Zeitlin
In prior studies of the current Shuttle Spacesuit (SSA), where basic fabric lay-ups were tested for shielding capabilities, it was found that the fabric portions of the suit give far less protection than previously estimated due to porosity and non-uniformity of fabric and LCVG components. In addition, overall material transmission properties were less than optimum. A number of alternate approaches are being tested to provide more uniform coverage and to use more efficient materials. We will discuss in this paper, recent testing of new material lay-ups/configurations for possible use in future spacesuit designs.
2002-07-15
Technical Paper
2002-01-2401
John W. Fisher, Suresh Pisharody, Mark J. Moran, Kanapathipillai Wignarajah, X. H. Xu, Yao Shi, Shih-Ger Chang
NASA Ames Research Center and Lawrence Berkeley National lab have completed a three-year joint NRA research project on the use of waste biomass to make a gaseous contaminant removal system. The objective of the research was to produce activated carbon from life support wastes and to use the activated carbon to adsorb and remove incineration flue gas contaminants such as NOx. Inedible biomass waste from food production was the primary waste considered for conversion to activated carbon. Previous research at NASA Ames has demonstrated the adsorption of both NOx and SO2 on activated carbon made from biomass and the subsequent conversion of adsorbed NOx to nitrogen and SO2 to sulfur. This paper presents the results testing the whole process system consisting of making, using, and regenerating activated carbon with relevant feed from an actual incinerator. Factors regarding carbon preparation, adsorption and regeneration are addressed.
2002-06-03
Technical Paper
2002-01-1948
Raymond A. Sutula, Kenneth L. Heitner, James A. Barnes, Tien Q. Duong, Connie Bezanson, Robert S. Kirk, Vince Battaglia, Gary Henriksen, Frank McLarnon, B. J. Kumar
The successful commercialization of Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) can provide significant benefits by reducing the United States' growing dependence on petroleum fuels for transportation; decreasing polluting and greenhouse gas emissions; and facilitating a long-term transition to sustainable renewable energy sources. Recognizing these benefits, the U.S. Department of Energy (DOE) supports an active program of long-range R&D to develop electric vehicle (EV) and hybrid electric vehicle (HEV) technologies and to accelerate their commercialization. The DOE Office of Advanced Automotive Technologies (OAAT) supports several innovative R&D programs, conducted in partnership with DOE's national laboratories, industry, other government agencies, universities, and small businesses. The Office has two key R&D cooperative agreements with the U.S. Advanced Battery Consortium (USABC) to develop high-energy batteries for EVs and high-power batteries for HEVs.
2000-07-10
Technical Paper
2000-01-2283
John W. Fisher, Suresh Pisharody, Mark J. Moran, Kanapathipillai Wignarajah, Yao Shi, Shih-Ger Chang
This paper presents the results from a joint research initiative between NASA Ames Research Center and Lawrence Berkeley National lab. The objective of the research is to produce activated carbon from life support wastes and to use the activated carbon to adsorb and chemically reduce the NOx and SO2 contained in incinerator flue gas. Inedible biomass waste from food production is the primary waste considered for conversion to activated carbon. Results to date show adsorption of both NOx and SO2 in activated carbon made from biomass. Conversion of adsorbed NOx to nitrogen has also been observed.
1999-08-02
Technical Paper
1999-01-2464
W. Jiang, X. Song, K. Kinoshita, T. Tran
Various techniques are used to characterize the physico-chemical properties of carbon materials (e.g., transmission electron microscopy, x-ray diffraction, and Raman spectroscopy) for Li-ion batteries. A convenient method to observe the chemical reactivity of carbons is to monitor their oxidation behavior by measuring the weight loss as carbon reacts with oxygen to form gaseous species such as CO and CO2. The results obtained by thermal analysis (TGA and DTA) of three types of cokes: (i) fluid coke, (ii) coal-tar pitch delayed coke and (iii) needle coke are presented. The aim of this paper is to utilize thermal analysis to investigate the active sites on petroleum and pitch cokes and to examine their affect on the irreversible capacity loss. Data from this study and the published literature are used in the analysis of the relationship between the physical properties of carbon and the irreversible capacity loss during the initial cycle.
Viewing 1 to 13 of 13

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