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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 667 records · Page 37

Progressive Hedging Decomposition for Solutions of Large-Scale Process Family Design Problems

In previous work, we have introduced a mathematical model for solving a discretized version of the process family design problem. This involves two sets of decision variables. One set selects which unit module designs are included in the process platform out of a candidate set of options; the other set determines which of these unit module designs are assigned to each variant. In this work, we exploit a parallelized Progressive Hedging (PH) algorithm to solve even larger scale design problems. PH is a well-known algorithm traditionally used to solve stochastic programming problems. While our problem is not a two-stage stochastic programming problem, the structure is similar, and it can be directly mapped to the PH approach, which we employ here to solve this deterministic optimization problem. We decompose our problem by process variant. We treat the platform unit module design variables as first-stage and the assignment of unit module designs to variants as second-stage, solving the problem using mpi-sppy. We demonstrate this approach on case studies of CC, water desalination, and refrigeration.

Stinchfield, Georgia↗

High-Fidelity, Large-Scale, Realistic Dataset Development

The final report summarizes the work performed for supporting the ARPA-E Grid Optimization Competition (Challenge 2 and Challenge 3) within the stated period. Challenge 2 For the challenge period, the main responsibility of the team is to investigate, gen- erate, and deliver parts of the data sets for the competition, based on the competition model for Challenge 2, existing data sets from Challenge 1, and data source supplied by other data set teams. Challenge 3 For the challenge period, the main responsibility of the team is to propose, create, deliver, and maintain the data format during the competition period. The data format will specify how the benchmark data will be represented and communicated to competitors. It will also specify how competitors should report back the solutions. The data format will be closely aligned with the problem formulation (maintained by the formulation team) and the solution validation process (maintained by the validation team). Our team is also responsible in investigating, generating, and delivering parts of the data sets for the competition. The data sets will be created based on the competition model for Challenge 3, existing data sets from Challenge 1 and Challenge 2, and data source supplied by other data set teams.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Electrochemical Production of Calcium Hydroxide from Calcium Carbonate

Calcium hydroxide is electrochemically synthesized to address SRNL core competency of Creating Manufacturing & Energy Solutions. This process is energy efficient compared to high temperature calcium carbonate decomposition to produce calcium oxide for the cement industry. Ultrasonic dehydration coupled with induction heating can further reduce the energy need for cement production.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Low-Temperature Plasma-Based Metrology of Lithium-Ion Battery Electrode Materials (CRADA Final Report)

As part of the Cyclotron Road program, SirenOpt Inc. evaluated its low-temperature plasma-based metrology sensor prototype for measuring multiple critical properties of lithium-ion battery electrode materials in parallel and in real-time. Cost-effective, minimal-waste manufacturing of high-performance battery electrode materials will be vital for achieving society’s net-zero carbon emission goals. Because existing electrode metrology sensors cannot operate within most sections of manufacturing lines, manufacturers often complete hundreds of processing steps before they can test their products and detect problems. When manufacturers perform these offline tests, they typically only test a small portion of the manufactured products. Current electrode manufacturing thus often yields many low-quality products, or off-spec products that must be thrown away all together. For example, at least 6% of the total lithium-ion battery manufacturing cost (i.e., over $250 million/year for the average gigafactory) is devoted to processing defective electrodes that are not scrapped until performance tests are failed during late-stage quality control checks. Electrode variability also leads manufacturers to build extra cells into battery packs to reduce the risk of poor performance. For example, many electric vehicle (EV) manufacturers include up to 10% more cells than needed, which substantially increases the cost and weight of the final EV product. The SirenOpt sensor can potentially enable early detection of poorly manufactured electrodes and allow them to be removed earlier from manufacturing lines, which can save battery manufacturers (hundreds of) millions of dollars per year. The sensor can further be used to improve product quality by accelerating R&D and process optimization, improving quality control, and enabling real-time process control. Overall, a real-time, in-situ metrology strategy can create unprecedented opportunities for implementation of smart manufacturing practices and advanced quality and process control solutions to realize higher battery electrode throughput and performance.

25 ENERGY STORAGE↗

Reduced backscattering cross section (Sigma degree) data from the Skylab S-193 radar altimeter

Backscattering cross section per unit scattering area data, reduced from measurements made by the Skylab S-193 radar altimeter over the ocean surface are presented. Descriptions of the altimeter are given where applicable to the measurement process. Analytical solutions are obtained for the flat surface impulse response for the case of a nonsymmetrical antenna pattern. Formulations are developed for converting altimeter AGC outputs into values for the backscattering cross section. Reduced data are presented for Missions SL-2, 3 and 4 for all modes of the altimeter where sufficient calibration existed. The problem of interpreting land scatter data is also discussed. Finally, a comprehensive error analysis of the measurement is presented and worst case random and bias errors are estimated.

Brown, G. S.↗

A numerical cloud model for the support of laboratory experimentation

A numerical cloud model is presented which can describe the evolution of a cloud starting from moist aerosol-laden air through the diffusional growth regime. The model is designed for the direct support of cloud chamber laboratory experimentation, i.e., experiment preparation, real-time control and data analysis. In the model the thermodynamics is uncoupled from the droplet growth processes. Analytic solutions for the cloud droplet growth equations are developed which can be applied in most laboratory situations. The model is applied to a variety of representative experiments.

Hagen, D. E.↗

Solar-Assisted Solution-Mining Concept

Brine heated in solar pond dissolves minerals from deposits. In proposed solution-mining process, hot brine is pumped down one well and recovered at one or more other wells. Emerging brine is rich in desired mineral. Brine is evaporated in solar ponds to recover mineral.

Dowler, W. L.↗

Study to establish cost predictions for the production of Redox chemicals

The chromium and iron chloride chemicals are significant first costs for NASA Redox energy storage systems. This study was performed to determine the lowest cost at which chromium and iron chlorides could be obtained for a complex of redox energy storage systems. In addition, since the solutions gradually become intermixed during the course of operation of Redox units, it was an objective to evaluate schemes for regeneration of the operating solutions. Three processes were evaluated for the production of chromium and iron chlorides. As a basis for the preliminary plant design and economic evaluation, it was assumed that the plant would produce about 25,000 tons of contained chromium as CrCl3 and an equivalent molar quantity of FeCl2. Preliminary plant designs, including materials and energy balances and sizing of major equipment, were prepared, and capital and operating costs were estimated.

Ammann, P. R.↗

Power-law X-ray and gamma-ray emission from relativistic thermal plasmas

A common characteristic of cosmic sources is power-law X-ray emission. Extragalactic sources of this type include compact components of active galactic nuclei (AGN). The present study is concerned with a theoretical model of such sources, taking into account the assumption that the power-law spectra are produced by repeated Compton scatterings of soft photons by relativistic thermal electrons. This is one of several possible physical mechanisms leading to the formation of a power-law spectrum. Attention is given to the Comptonization of soft photon sources, the rates of pair processes, the solution of the pair equilibrium equation, and the constraints on a soft photon source and an energy source. It is concluded that the compactness parameters L/R of most of the cosmic sources observed to date lie below the maximum luminosity curves considered.

Zdziarski, A. A.↗

Synthesis, curing and physical behavior of maleimide terminated poly(arylene ethers)

This paper describes the synthesis of maleimide terminated poly(ether ketones) using the solution imidization process described by Summers et al. (1987). Amorphous poly(arylene ether ketones), as well as poly(arylene ether sulfones, of controlled end group functionalities and molecular weights were synthesized by nucleophilic step polymerization of bisphehol-A phenolates with activated halides, such as 4,4'-difluorobenzophenone, and 'monofunctional' end cappers such as m-aminophenol. The thermal properties of the system included glass transition temperature (Tg) values of 160-170 C, with modulus above Tg proportional to cross-link density, which in turn was reciprocally related to oligomer molecular weight. The measurements of the fracture toughness values showed the materials to be very ductile, with the toughness increasing with oligomer molecular weight.

Lyle, G. D.↗

Upwind scheme for solving the Euler equations on unstructured tetrahedral meshes

An upwind scheme is presented for solving the three-dimensional Euler equations on unstructured tetrahedral meshes. Spatial discretization is accomplished by a cell-centered finite-volume formulation using flux-difference splitting. Higher-order differences are formed by a multidimensional linear reconstruction process. The solution gradients required for the higher-order differenes are computed by a novel approach that yields highly resolved solutions in regions of smooth flow while avoiding oscillations across shocks without explicitly applying a limiter. Solutions are advanced in time by a three-stage Runge-Kutta time-stepping scheme with convergence accelerated to steady state by local time stepping and implicit residual smoothing. Transonic solutions are presented for two meshes around the ONERA M6 wing and demonstrate substantial accuracy and insensitivity to mesh size.

Frink, Neal T.↗

Ordered organic thin films self-assembled from the vapor phase

Organic films self-assembled from a liquid phase, as in Langmuir-Blodgett or adsorption from solution, have received much attention in the past decade as techniques to achieve highly oriented-ordered polymeric thin films. Many organic compounds including some of the same fatty acids have been vapor deposited as well. However, organic pigments and dyes comprise a major class of important materials which have very low solubilities yet excellent thermal stabilities, making them ideally suited for film deposition from the vapor phase. Surprisingly, such molecular systems exhibit a significant propensity to self order, a high sensitivity to deposition parameters, and a range of microstructural forms that cannot be duplicated by the less energetic mechanisms associated with solution adsorption processes. Molecular solids such as heterocyclic polynuclear aromatics are excellent candidates for film formation by vacuum deposition means. Over the past decade, our work and that of others investigating a wide variety of perylene and phthalocyanine derivatives identified five deposition parameters that can significantly affect film morphology, physical microstructure, and type and extent of ordering developed in vacuum and vapor transport grown films. These parameters are substrate temperature, deposition rate, substrate chemistry and epitaxy, ambient gas convective flows, and post deposition annealing. Examples of how each of these conditions manifest themselves in the film structure and ordering, most frequently revealed by scanning electron microscopy, reflection absorption infrared spectroscopy (RAIR), and grazing incidence x-ray diffraction (GIX), are presented.

Debe, M. K.↗

Value added data archiving

Researchers in the Molecular Sciences Research Center (MSRC) of Pacific Northwest Laboratory (PNL) currently generate massive amounts of scientific data. The amount of data that will need to be managed by the turn of the century is expected to increase significantly. Automated tools that support the management, maintenance, and sharing of this data are minimal. Researchers typically manage their own data by physically moving datasets to and from long term storage devices and recording a dataset's historical information in a laboratory notebook. Even though it is not the most efficient use of resources, researchers have tolerated the process. The solution to this problem will evolve over the next three years in three phases. PNL plans to add sophistication to existing multilevel file system (MLFS) software by integrating it with an object database management system (ODBMS). The first phase in the evolution is currently underway. A prototype system of limited scale is being used to gather information that will feed into the next two phases. This paper describes the prototype system, identifies the successes and problems/complications experienced to date, and outlines PNL's long term goals and objectives in providing a permanent solution.

Berard, Peter R.↗

Scheduling with genetic algorithms

In many domains, scheduling a sequence of jobs is an important function contributing to the overall efficiency of the operation. At Boeing, we develop schedules for many different domains, including assembly of military and commercial aircraft, weapons systems, and space vehicles. Boeing is under contract to develop scheduling systems for the Space Station Payload Planning System (PPS) and Payload Operations and Integration Center (POIC). These applications require that we respect certain sequencing restrictions among the jobs to be scheduled while at the same time assigning resources to the jobs. We call this general problem scheduling and resource allocation. Genetic algorithms (GA's) offer a search method that uses a population of solutions and benefits from intrinsic parallelism to search the problem space rapidly, producing near-optimal solutions. Good intermediate solutions are probabalistically recombined to produce better offspring (based upon some application specific measure of solution fitness, e.g., minimum flowtime, or schedule completeness). Also, at any point in the search, any intermediate solution can be accepted as a final solution; allowing the search to proceed longer usually produces a better solution while terminating the search at virtually any time may yield an acceptable solution. Many processes are constrained by restrictions of sequence among the individual jobs. For a specific job, other jobs must be completed beforehand. While there are obviously many other constraints on processes, it is these on which we focussed for this research: how to allocate crews to jobs while satisfying job precedence requirements and personnel, and tooling and fixture (or, more generally, resource) requirements.

Fennel, Theron R.↗

Alternatives to Silicon Rubber Thermal Barrier in RSRM Nozzle Joints

Thiokol Propulsion encountered a situation where gas path can form in the Filler material in joints between the phenolic in the Space Shuttle Reusable Solid Rocket Motor nozzle. An investigation determined that the method for injecting the filler material into the joint created a pressurized pocket of air that forced its way to the surface while the filler was curing. The path that the air took remained open some situations leaving a path for hot gas to get deep into the joint. The condition that created the gas path has been corrected by modifications to the manufacturing process, but a design solution that would reduce processing time is being pursued. A strip of open cell installed deep into the joint, can serve as a barrier to the Filler material. Testing indicates that the foam eliminates the pressure pocket, and does not prevent detection of leakage of the o-ring seals during leak test. Open cell foam does not have thermal resistance capability and mechanical structure, which would be required in the event of a gas path. A replacement to open cell foam is now being considered. Braided carbon fiber rope has the permeability characteristics of foam and it has thermal resistance characteristics as well. Braided carbon fiber rope (BCFR) has been tested in simulated joints in subscale rocket motor. Results of the testing indicate that braided carbon fiber rope can significantly reduce gas temperature by as much es 3000 F in a nozzle joint configuration. BCFR can be installed as a barrier to stop the joint filler material or it can used as the thermal barrier alone.

Totman, Peter D.↗

NASA's Secured Advanced Federated Environment

In 1999, a NASA-wide team initially set out to create a collaborative environment to enable NASA's scientists and engineers to share information and tools across NASA locations and with world-wide partners. This paper describes the team's development process and solutions in resolving conflicting security issues of building a complex intra/inter-enterprise collaborative system. Based on the federated, hierarchical, compartmentalized principles, the Secured Advanced Federated Environment (SAFE) developed by the team is becoming a foundational element for building a collaborative infrastructure for NASA. This paper also introduces the concept of a Micro Security Domain which can achieve the balance between the need to collaborate and the need to enforce enterprise and local security rules. SAFE'S federated security concepts enables networks to be formed around the functional/security requirements. With the SAFE technologies and approaches, security will not be an afterthought of the enterprise network design.

network designs↗