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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 505 records · Page 28

Piecewise Linear Optimization for Public EV Charging Depots in Different Utility Environments

With the proliferation of electric vehicles (EVs), EV supply equipment technology is being pushed to increasingly higher power levels, such as extreme fast charging (XFC) at 300kW or more. As more public XFC depots are connected to electric distribution systems, utility operators will mitigate their impact with pricing schemes and programs such as demand response, demand charges, and time-varying prices. In this paper we describe an XFC management system that combines an on-site battery energy storage system and an optimization application that minimizes the cost to operate the depot in light of the utility pricing programs. We have designed the optimizer specially to use fast and simple linear programming so that it can be deployed to low-cost computing platforms. We also describe how several utility pricing schemes are integrated into a single piecewise model, reducing the engineering effort to implement the optimizer in different utility environments.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Concentrating Solar Power and Water Issues in the U.S. Southwest

Concentrating solar power (CSP) systems utilize the sun's energy to create heat that is used to generate electrical power. CSP systems in the United States are installed primarily in the Southwest, with 92% of plants that are operational, under construction, or under development located in three western states--Arizona, California, and Nevada. This report provides an overview of CSP development in these states, or the 'Southwest' for the purposes of this discussion, with a particular focus on the water supply issues associated with CSP. The Western Governors' Association (WGA) commissioned staff from the Western States Water Council (WSWC) to collaborate with staff from the National Renewable Energy Laboratory (NREL) to prepare this report. The WGA has long supported the effective management of the West's water resources, as well as the development of a clean, diverse, reliable, and affordable energy supply consisting of traditional and renewable energy resources. This report is specifically intended to help inform these goals, especially as WGA continues to underwrite a Regional Transmission Expansion Planning project, undertaken by the WSWC and the Western Electricity Coordinating Council (WECC), to better understand energy development within the existing and future water resource constraints of the West. This report builds upon earlier research conducted by NREL, the University of Colorado-Boulder, and Stanford University that was supported through the Joint Institute for Strategic Energy Analysis (JISEA) and presents information gathered through extensive research and literature reviews, as well as interviews and outreach with state water administrators and energy regulators, WECC and other experts familiar with CSP development in the Southwest.

14 SOLAR ENERGY↗

Defense strategies for asymmetric networked systems under composite utilities

We consider an infrastructure of networked systems with discrete components that can be reinforced at certain costs to guard against attacks. The communications network plays a critical, asymmetric role of providing the vital connectivity between the systems. We characterize the correlations within this infrastructure at two levels using (a) aggregate failure correlation function that specifies the infrastructure failure probability giventhe failure of an individual system or network, and (b) first order differential conditions on system survival probabilities that characterize component-level correlations. We formulate an infrastructure survival game between an attacker and a provider, who attacks and reinforces individual components, respectively. They use the composite utility functions composed of a survival probability term and a cost term, and the previously studiedsum-form and product-form utility functions are their special cases. At Nash Equilibrium, we derive expressions for individual system survival probabilities and the expected total number of operational components. We apply and discuss these estimates for a simplified model of distributed cloud computing infrastructure

Rao, Nageswara S.↗

Understanding I/O workload characteristics of a Peta-scale storage system

Understanding workload characteristics is critical for optimizing and improving the performance of current systems and software, and architecting new storage systems based on observed workload patterns. In this paper, we characterize the I/O workloads of scientific applications of one of the world's fastest high performance computing (HPC) storage cluster, Spider, at the Oak Ridge Leadership Computing Facility (OLCF). OLCF flagship petascale simulation platform, Titan, and other large HPC clusters, in total over 250 thousands compute cores, depend on Spider for their I/O needs. We characterize the system utilization, the demands of reads and writes, idle time, storage space utilization, and the distribution of read requests to write requests for the Peta-scale Storage Systems. From this study, we develop synthesized workloads, and we show that the read and write I/O bandwidth usage as well as the inter-arrival time of requests can be modeled as a Pareto distribution. We also study the I/O load imbalance problems using I/O performance data collected from the Spider storage system.

I/O↗

Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Valuation Diagramming and Accounting of Transactive Energy Systems

Transactive energy (TE) systems support both economic and technical objectives of a power system including efficiency and reliability. TE systems utilize value-driven mechanisms to coordinate and balance responsive supply and demand in the power system. Economic performance of TE systems cannot be assessed without estimating their value. Estimating the potential value of transactive energy systems requires a systematic valuation methodology that can capture value exchanges among different stakeholders (i.e., actors) and ultimately estimate impact of one TE design and compare it against another one. Such a methodology can help decision makers choose the alternative that results in preferred outcomes. This paper presents a valuation methodology developed to assess value of TE systems. A TE use-case example is discussed, and metrics identified in the valuation process are quantified using a TE simulation program.

Makhmalbaf, Atefe↗

Progress Towards Commercialization of Electrochemical Membrane Technology for CO2 Capture and Power Generation

To address the concerns about climate change resulting from emission of CO2 by coal-fueled power plants, FuelCell Energy, Inc. has developed Combined Electric Power and Carbon-dioxide Separation (CEPACS) system concept, as a novel solution for greenhouse gas emission reduction. The CEPACS system utilizes Electrochemical Membrane (ECM) technology derived from the Company’s well established Direct FuelCell® products. The system concept works as two devices in one: it separates the CO2 from the exhaust of other plants and simultaneously, using a supplementary fuel, produces electric power at high efficiency. FCE is currently evaluating the use of ECM to cost effectively separate CO2 from the flue gas of coal fired power plants under a U.S. Department of Energy contract. The overarching objective of the project is to verify that the ECM can achieve at least 90% CO2 capture from flue gas of a PC plant with no more than 35% increase in the cost of electricity. The specific objectives and related activities presently ongoing for the project include: 1) conduct bench scale tests of ECM and 2) evaluate the effects of impurities present in the coal plant flue gas by laboratory scale performance tests of the membrane.

carbon↗

The development of a residential heating and cooling system using NASA derived technology

A study to determine the technical and economic feasibility of a solar-powered space heating, air-conditioning, and hot water heating system for residential applications is presented. The basic system utilizes a flat-plate solar collector to process incident solar radiation, a thermal energy storage system to store the collected energy for use during night and heavily overcast periods, and an absorption cycle heat pump for actually heating and cooling the residence. In addition, heat from the energy storage system is used to provide domestic hot water. The analyses of the three major components of the system (the solar collector, the energy storage system, and the heat pump package) are discussed and results are presented. The total system analysis is discussed in detail, including the technical performance of the solar-powered system and a cost comparison between the solar-powered system and a conventional system. The projected applicability of the system to different regions of the nation is described.

Oneill, M. J.↗

Design and test of a self-controlled heat pipe radiator.

A 15,000-W spacecraft waste heat rejection system utilizing heat pipe radiator panels has been investigated. Of the several concepts initially identified, a series system was selected for more in-depth analysis. As a demonstration of system feasibility, a nominal 500-W radiator panel has been designed, built, and bench tested. The panel, which is a module of the 15,000-W system, consists of a variable conductance heat pipe (VCHP) header, and six isothermalizer heat pipes attached to a radiator. The thermal load to the VCHP is supplied by a Freon 21 liquid loop via an integral heat exchanger. This paper describes the results of the system studies and the radiator design. Also presented are test data on the VCHP, heat exchanger and isothermalizer heat pipes.

Swerdling, B.↗

Free radical propulsion concept

The concept of a free radical propulsion system, utilizing the recombination energy of dissociated low molecular weight gases to produce thrust, is analyzed. The system, operating at a theoretical impulse with hydrogen, as high as 2200 seconds at high thrust to power ratio, is hypothesized to bridge the gap between chemical and electrostatic propulsion capabilities. A comparative methodology is outlined by which characteristics of chemical and electric propulsion for orbit raising mission can be investigated. It is noted that free radicals proposed in rockets previously met with difficulty and complexity in terms of storage requirements; the present study proposes to eliminate the storage requirements by using electric energy to achieve a continuous-flow product of free radicals which are recombined to produce a high velocity propellant. Microwave energy used to dissociate a continuously flowing gas is transferred to the propellant via three-body-recombination for conversion to propellant kinetic energy. Microwave plasma discharge was found in excess of 90 percent over a broad range of pressure in preliminary experiments, and microwave heating compared to electrothermal heating showed much higher temperatures in gasdynamic equations.

Hawkins, C. E.↗

Altitude testing of a flight weight, self-cooled, 2D thrust vectoring exhaust nozzle

The Augmented Deflector Exhaust Nozzle (ADEN) was tested in PSL-3 at NASA-Lewis Research Center using an F404 engine. The ADEN is a flight weight Single Expansion Ramp Nozzle with thrust vectoring, an internal cooling system utilizing the available engine fan flow, and a variable area throat controlled by the engine control system. Test conditions included dry and max A/B operation at nozzle pressure ratios from 2.0 to 15.0. High nozzle pressure loading was simulated to verify structural integrity at near maximum design pressure. Nozzle settings covered the full range in throat area and + or - 15 deg deflection angle. Test results demonstrated expected aerodynamic performance, cooling system effectiveness, control system stability, and mechanical integrity.

Wooten, W. H.↗

Four spot laser anemometer and optical access techniques for turbine applications

A time-of-flight anemometer (TOFA) system, utilizing a spatial lead-lag filter for bipolar pulse generation was constructed and tested. This system, called a Four Spot Laser Anemometer, was specifically designed for use in high speed, turbulent flows in the presence of walls or surfaces. The TOFA system uses elliptical spots to increase the flow acceptance angle to be comparable with that of a fringe type anemometer. The tightly focused spots used in the Four Spot yield excellent flare light rejection capabilities. Good results were obtained to 75 microns normal to a surface, with a f/2.5 collecting lens. This system is being evaluated for use in a warm turbine facility. Results from both a particle lag velocity experiment and boundary layer profiles will be discussed. In addition, an analysis of the use of curved windows in a turbine casing will be presented. Curved windows, matching the inner radius of the turbine casing, preserve the flow conditions, but introduce astigmatic aberrations. A correction optic was designed that virtually eliminates these astigmatic aberrations throughout the intrablade survey region for normal incidence.

Wernet, Mark P.↗

Microgravity fluid management requirements of advanced solar dynamic power systems

The advanced solar dynamic system (ASDS) program is aimed at developing the technology for highly efficient, lightweight space power systems. The approach is to evaluate Stirling, Brayton and liquid metal Rankine power conversion systems (PCS) over the temperature range of 1025 to 1400K, identify the critical technologies and develop these technologies. Microgravity fluid management technology is required in several areas of this program, namely, thermal energy storage (TES), heat pipe applications and liquid metal, two phase flow Rankine systems. Utilization of the heat of fusion of phase change materials offers potential for smaller, lighter TES systems. The candidate TES materials exhibit large volume change with the phase change. The heat pipe is an energy dense heat transfer device. A high temperature application may transfer heat from the solar receiver to the PCS working fluid and/or TES. A low temperature application may transfer waste heat from the PCS to the radiator. The liquid metal Rankine PCS requires management of the boiling/condensing process typical of two phase flow systems.

Migra, Robert P.↗

Lightning First Pulses Used in the "Last" (Time-of-Arrival) and "Atlas" (Single Station) Total Lightning Mapping Systems

The first RF pulse from "total lightning' discharges (cloud and ground flashes) has been used in different ways to locate the origin of flashes in two new types of lightning detection systems. The multisensor LASI time-of-arrival (TOA) system uses GPS timing of the first pulse. The ATLAS single sensor system uses the amplitude of the first pulse, which is invariant in magnitude and polarization for all lightning discharges, to determine distance from the sensor. It is significantly more accurate than past single sensor lightning mapping systems. The polarity of the first pulse generally identifies lightning type (IC or CG). Both systems utilize only the first pulse which makes signal processing much simpler than with previous lightning locating systems. Knowing the position where lightning begins (maximum electric fields, mixed phase hydrometeors and updrafts) is valuable for identifying convective cells producing the hazardous meteorological conditions caused by thunderstorms. It is also important for research studying thunderstorm electrification and associated microphysical problems.

Markson, Ralph↗

Digital Radar-Signal Processors Implemented in FPGAs

High-performance digital electronic circuits for onboard processing of return signals in an airborne precipitation- measuring radar system have been implemented in commercially available field-programmable gate arrays (FPGAs). Previously, it was standard practice to downlink the radar-return data to a ground station for postprocessing a costly practice that prevents the nearly-real-time use of the data for automated targeting. In principle, the onboard processing could be performed by a system of about 20 personal- computer-type microprocessors; relative to such a system, the present FPGA-based processor is much smaller and consumes much less power. Alternatively, the onboard processing could be performed by an application-specific integrated circuit (ASIC), but in comparison with an ASIC implementation, the present FPGA implementation offers the advantages of (1) greater flexibility for research applications like the present one and (2) lower cost in the small production volumes typical of research applications. The generation and processing of signals in the airborne precipitation measuring radar system in question involves the following especially notable steps: The system utilizes a total of four channels two carrier frequencies and two polarizations at each frequency. The system uses pulse compression: that is, the transmitted pulse is spread out in time and the received echo of the pulse is processed with a matched filter to despread it. The return signal is band-limited and digitally demodulated to a complex baseband signal that, for each pulse, comprises a large number of samples. Each complex pair of samples (denoted a range gate in radar terminology) is associated with a numerical index that corresponds to a specific time offset from the beginning of the radar pulse, so that each such pair represents the energy reflected from a specific range. This energy and the average echo power are computed. The phase of each range bin is compared to the previous echo by complex conjugate multiplication to obtain the mean Doppler shift (and hence the mean and variance of the velocity of precipitation) of the echo at that range.

Berkun, Andrew↗

Cumulative Measurement Errors for Dynamic Testing of Space Flight Hardware

Located at the NASA Johnson Space Center in Houston, TX, the Six-Degree-of-Freedom Dynamic Test System (SDTS) is a real-time, six degree-of-freedom, short range motion base simulator originally designed to simulate the relative dynamics of two bodies in space mating together (i.e., docking or berthing). The SDTS has the capability to test full scale docking and berthing systems utilizing a two body dynamic docking simulation for docking operations and a Space Station Remote Manipulator System (SSRMS) simulation for berthing operations. The SDTS can also be used for nonmating applications such as sensors and instruments evaluations requiring proximity or short range motion operations. The motion base is a hydraulic powered Stewart platform, capable of supporting a 3,500 lb payload with a positional accuracy of 0.03 inches. The SDTS is currently being used for the NASA Docking System testing and has been also used by other government agencies. The SDTS is also under consideration for use by commercial companies. Examples of tests include the verification of on-orbit robotic inspection systems, space vehicle assembly procedures and docking/berthing systems. The facility integrates a dynamic simulation of on-orbit spacecraft mating or de-mating using flight-like mechanical interface hardware. A force moment sensor is used for input during the contact phase, thus simulating the contact dynamics. While the verification of flight hardware presents unique challenges, one particular area of interest involves the use of external measurement systems to ensure accurate feedback of dynamic contact. The measurement systems for the test facility have two separate functions. The first is to take static measurements of facility and test hardware to determine both the static and moving frames used in the simulation and control system. The test hardware must be measured after each configuration change to determine both sets of reference frames. The second function is to take dynamic measurements during hardware motion and contact. While performing dynamic testing of an active docking system, researchers found that the data from the motion platform, test hardware and two external measurement systems exhibited frame offsets and rotational errors. While the errors were relatively small when considering the motion scale overall, they substantially exceeded the individual accuracies for each component. After evaluating both the static and dynamic measurements, researchers found that the static measurements introduced significantly more error into the system than the dynamic measurements even though, in theory, the static measurement errors should be smaller than the dynamic. In several cases, the magnitude of the errors varied widely for the static measurements. Upon further investigation, researchers found the larger errors to be a consequence of hardware alignment issues, frame location and measurement technique whereas the smaller errors were dependent on the number of measurement points. This paper details and quantifies the individual and cumulative errors of the docking system and describes methods for reducing the overall measurement error. The overall quality of the dynamic docking tests for flight hardware verification was improved by implementing these error reductions.

Winnitoy, Susan↗

Carbon Capture Design and Costing: Phase 2 (C3DC2) (Final Project Report)

ION Clean Energy’s (ION) advanced solvent is one of the leading solvent systems currently under development for post-combustion carbon dioxide (CO 2 ) capture. ION has partnered with Nebraska Power Public District (NPPD), Sargent & Lundy, Koch Modular Process Systems, and Siemens to design a commercial-scale (700 MW) capture system utilizing ION’s advanced solvent, ICE-21, retrofitted onto NPPD’s Gerald Gentleman Station in Sutherland, Nebraska, USA. The capture system was designed to take full advantage of the solvent benefits including an efficient physical plant layout, reduced energy requirements, less solvent degradation, lower emissions, and lower capital costs relative to systems built with DOE BBS case benchmark solvents. This Front-End Engineering Design (FEED) study also included an investigation of utilizing biomass co-combustion with the aim of reaching near-zero emissions for this coal-fired power generating unit. The targeted biomass was from local resources in Nebraska tied to the production of ethanol.

01 COAL, LIGNITE, AND PEAT↗