SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
This is the Performance Verification Report, Final Comprehensive Performance Test Report, P/N 1331200-2-TST, S/N 108/A2, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
This is the Performance Verification Report, Initial Comprehensive Performance Test Report, P/N 1331720-2-IT, S/N 108/Al, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).
This is the performance Verification Report, Final Comprehensive Performance Test Report, P?N 1331720-3-TST, S/N 109/A1, for the Integrated-Advanced Microwave Sounding Unit-A (AMSU-A).
The approach of this task was to apply leading parallel computing research to a number of existing techniques for assimilation, and extract parameters indicating where and how input/output limits computational performance. The following was used for detailed knowledge of the application problems: 1. Developing a parallel input/output system specifically for this application 2. Extracting the important input/output characteristics of data assimilation problems; and 3. Building these characteristics s parameters into our runtime library (Fortran D/High Performance Fortran) for parallel input/output support.
The stator-blade angles in the twelfth through fifteenth stages of a 16-stage axial-flow compressor were increased 3O. The over-all performance of this modified compressor is compared to the performance of the compressor with original blade angles. The matching characteristics of the modified compressor and a two-stage turbine were obtained and compared to those of the compressor with original blade angles and the same turbine.
The stator-blade angles in the first four stages of a 16-stage axial-flow compressor were increased in order to decrease the angles of attack of these stages, and thereby to improve part-speed performance. The performance of this modified compressor was compared with that of the same compressor with original blade angles.
The stator-blade angles in the twelfth to fifteenth stages of a 16-stage high-pressure-ratio axial-flow compressor were decreased 3 deg The over-all performance of this compressor is compared with the performance of the same compressor with standard blade angles. The matching characteristics of the modified compressor and a two-stage turbine were also obtained and compared with those of the compressor with the original blade angles and the same turbine.
Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F(2008) or ASTM D 7566 (2010) standards, respectively, and are classified as drop-in fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are certified individually on the basis of feedstock. Adherence to alternate fuels and fuel blends requires smart fueling systems or advanced fuel-flexible systems, including combustors and engines without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance (Part A) and emissions and particulates (Part B) combustor sector data for synthetic-parafinic-kerosene- (SPK-) type fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling.
GEIA-STD-0005-1 defines the objectives of, and requirements for, documenting processes that assure customers and regulatory agencies that AHP electronic systems containing lead-free solder, piece parts, and boards will satisfy the applicable requirements for performance, reliability, airworthiness, safety, and certify-ability throughout the specified life of performance. It communicates requirements for a Lead-Free Control Plan (LFCP) to assist suppliers in the development of their own Plans. The Plan documents the Plan Owner's (supplier's) processes, that assure their customer, and all other stakeholders that the Plan owner's products will continue to meet their requirements. The presentation reviews quality assurance requirements traceability and LFCP template instructions.
A challenge facing the U.S. National Highway Traffic Safety Administration (NHTSA), as well as international safety experts, is the need to educate car drivers about the dangers associated with performing distraction tasks while driving. Researchers working for the U.S. Army Research Laboratory have developed a technique for predicting the increase in mental workload that results when distraction tasks are combined with driving. They implement this technique using human performance modeling. They have predicted workload associated with driving combined with cell phone use. In addition, they have predicted the workload associated with driving military vehicles combined with threat detection. Their technique can be used by safety personnel internationally to demonstrate the dangers of combining distracter tasks with driving and to mitigate the safety risks.
The GOES-R flight project has developed the Image Navigation and Registration (INR) Performance Assessment Tool Set (IPATS) to perform independent INR evaluations of the optical instruments on the GOES-R series spacecraft. In this presentation, we document the development of navigation (NAV) evaluation capabilities within IPATS for the Geostationary Lightning Mapper (GLM). We also discuss the post-processing quality filtering developed for GLM NAV, and present example results for several GLM background image datasets. Initial results suggest that GOES-16 GLM is compliant with navigation requirements.
The Cassini mission was a highly successful 20-year mission to the planet Saturn that launched in 1997 and concluded its mission in September 2017. Over the course of its mission, Cassini executed hundreds of main engine and thruster-controlled ΔV maneuvers. This paper provides an overview of the Cassini maneuvers and provides data on the performance of the attitude controller and maneuver execution errors during these maneuvers. The paper concludes with an appendix documenting the vital statistics for all maneuvers that Cassini performed.
An investigation of the NASA High Efficiency Centrifugal Compressor (HECC) vaneless diffuser configuration was performed. This multipart investigation focused on validating the computational model against experimental data. The validated model was then used to explore the effects of observed geometric differences between the as-manufactured and design-intent impellers. Lastly, the validated model was used for comparison against an experimental tip clearance study. Details regarding each of the parts are detailed below: This second part of a multipart investigation of the NASA HECC vaneless diffuser configuration focused on the comparison of the as-manufactured HECC vaneless computational model validated in Part I against a new model that used the same grid and solver settings but replaced the impeller section data with the design-intent sections from NASA/CR-2014-218114/Rev1. The 1D performance values showed that the as-manufactured impeller underperformed compared to the design-intent for all four speedlines that were simulated. Further investigation of radial profiles, loading and contours showed consistent underperformance of the as-manufactured. An investigation into the source of the difference led to the discovery of several geometric differences in the two impellers of magnitudes that could not be explained outside of manufacturing. The differences that were observed can be summarized into four categories: fillets, TE exit radius differences, splitter LE differences and main blade thickness differences. The investigation then shifted to attempting to isolate the geometric differences as best as possible and to understand their contribution to the observed underperformance. The investigation showed that out of the four geometric differences that were explored, the differences in the splitter blade had the largest effect.
This report offers analysis and design insights for leveraging High-Performance Computing (HPC) to predict line-of-sight (LOS) Global Navigation Satellite System (GNSS) availability in a city. This work is motivated by the emerging fields of Advanced and Urban Air Mobility (AAM/UAM), where regulatory authorities are seeking city-scale, meter-resolution risk forecasting in order to safely integrate new flight missions with existing urban life and infrastructure. This work addresses the technical challenge of efficiently computing urban GNSS satellite visibility to predict GNSS performance metrics under these requirements. We present a new HPC-optimized shadow casting algorithm variant as a ray-based approach to forecasting satellite visibility. We apply this algorithm variant in a software-defined prognostic service which generates a GNSS navigation risk-correlated map as a path planning-style potential field. We detail dominant computational burdens, viable simplifying assumptions, and different algorithmic implementations, intending to demonstrate a baseline of computation time needed by each stage in such a service. We conclude by analyzing the prototype service’s prediction accuracy compared to receiver data from Corpus Christi, Texas. This informs design trade-offs along the dimensions of hardware, computation time, and tolerable forecasting error (including proportions of false positives and false negatives).
Cold climate Heat Pumps (CCHPs) using single-speed compressors in tandem have been successfully built and tested to reach its performance metrics with outdoor temperatures as low as -25°C. CCHPs must be designed to alleviate the problems of too high discharge temperatures, low suction pressure and high-pressure ratio at low ambient conditions and insufficient heating capacity relative to the heating capacity at 8.3°C. In this paper we recognize those concerns. Low-GWP refrigerants are screened based on the shape of their T-S saturation boundary. Simulations of the performance of low-GWP refrigerants (R32, R454B, R466A, and R452B) relative to R410A is done using the DOE/ORNL Heat Pump Design Model at the component level. Systemic inefficiency, the root cause of lost work, is addressed by component-level exergy analysis to refine design options. CCHPs using low-GWP refrigerants addresses issues of reducing energy consumption, lowering carbon footprint, and enabling environmentally sustainability. The CCHP was designed to meet a HSPF > 11.0 and SEER > 15.0 having adequate heat pump heating capacity down to -25°C. It is estimated that at least 2.6 million U.S homes using electric furnaces and heat pumps in cold or very old climates with an annual energy consumption of 0.17EJ would benefit by CCHPs.
Biomass derived monomers can offer unique functionality, often in the forms of heteroatoms, that is not easily accessible by routine petrochemical routes. Importantly, many of these monomers offer the potential to replace the petrochemical monomers used in the manufacture of thermosets to enable expanded functionality and performance. In the present work, we leverage amine containing monomers that can be obtained via biological conversions in both epoxy and benzoxazine thermosets. These monomers have a wide degree of functionality available to them that augment the material properties. In the case of benzoxazines, monomers that contain both an amine and carboxylic acid are used and the presence of the carboxylic acid leads to an acceleration in cure kinetics and a dramatic reduction in cure temperature. For the epoxy thermosets, multifunctional amine monomers are used as a hardener and the properties of the resultant materials are found to scale with the spacing and identity between reactive centers. The amines can be further modified and reacted to produce a mixed network of triazines and epoxy-amines that enables the end-of-life degradation of these materials. Importantly, subsequent process analysis reveals that the use of bioderived amines can present dramatic reductions in both supply chain energy and GHG emissions while possessing a cost similar to their petrochemical counterparts. Overall, this work demonstrates the robust potential to use bioderived amines for performance advantaged properties.
Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm. Exhaust pressures and temperatures were determined from an analysis of indicator cards. The analysis showed that, at rich mixtures with the exhaust back pressure equal to the inlet-air pressure, there is excess energy available for driving a turbine over that required for supercharging. The presence of this excess energy indicates that a highly supercharged compression-ignition engine might be desirable as a compressor and combustion chamber for a turbine.
This paper describes the reconstruction of electrons and photons with the ATLAS detector, as employed for measurements and searches exploiting the complete LHC Run 2 dataset. An improved energy clustering algorithm is introduced, and its implications for the measurement and identification of electrons and photons are discussed in detail. Corrections and calibrations that affect performance, including energy calibration, identification and isolation efficiencies, and the measurement of the charge of reconstructed electron candidates are determined using up to 81 fb -1 of proton-proton collision data collected at $\sqrt{s}=$ 13 TeV between 2015 and 2017.