Results for “Performance tests” — Page 79

NASA NTRS1999

Elimination of High-Frequency Combustion Instability in the Fastrac Engine Thrust Chamber

A series of tests were conducted to stabilize the combustion of the Fastrac engine thrust chamber. The first few stability tests resulted in unstable combustion due ineffective acoustic cavity designs. The thrust chamber exhibited unstable combustion in the first-tangential mode and its harmonics. Combustion was stabilized by increasing the volume of the acoustic cavities and by plugging the dump-cooling orifices so that the cavities were uncooled. Although the first few stability tests resulted in unstable combustion, prior and subsequent long-duration performance tests of the Fastrac thrust chamber were spontaneously stable. Stability considerations during the injector faceplate design were based on the Hewitt correlation.

Rocker, Marvin↗

NASA NTRS1999

Elimination of High-Frequency Combustion Instability in the Fastrac Engine Thrust Chamber

A series of tests were conducted to stabilize the combustion of the Fastrac engine thrust chamber. The first few stability tests resulted in unstable combustion due ineffective acoustic cavity designs. The thrust chamber exhibited unstable combustion in the first-tangential mode and its harmonics. Combustion was stabilized by increasing the volume of the acoustic cavities and by plugging the dump-cooling orifices so that the cavities were uncooled. Although the first few stability tests resulted in unstable combustion, prior and subsequent long-duration performance tests of the Fastrac thrust chamber were spontaneously stable. Stability considerations during the injector faceplate design were based on the Hewitt correlation.

Rocker, Marvin↗

NASA NTRS2006

An Assessment of NASA Glenn's Aeroacoustic Experimental and Predictive Capabilities for Installed Cooling Fans: Aerodynamic Performance - Part 1

Driven by the need for low production costs, electronics cooling fans have evolved differently than the bladed components of gas turbine engines which incorporate multiple technologies to enhance performance and durability while reducing noise emissions. Drawing upon NASA Glenn's experience in the measurement and prediction of gas turbine engine aeroacoustic performance, tests have been conducted to determine if these tools and techniques can be extended for application to the aerodynamics and acoustics of electronics cooling fans. An automated fan plenum installed in NASA Glenn's Acoustical Testing Laboratory was used to map the overall aerodynamic and acoustic performance of a spaceflight qualified 80 mm diameter axial cooling fan. In order to more accurately identify noise sources, diagnose performance limiting aerodynamic deficiencies, and validate noise prediction codes, additional aerodynamic measurements were recorded for two operating points: free delivery and a mild stall condition. Non-uniformities in the fan s inlet and exhaust regions captured by Particle Image Velocimetry measurements, and rotor blade wakes characterized by hot wire anemometry measurements provide some assessment of the fan aerodynamic performance. The data can be used to identify fan installation/design changes which could enlarge the stable operating region for the fan and improve its aerodynamic performance and reduce noise emissions.

VanZante, Dale E.↗

NASA NTRS2012

Ice Growth Measurements from Image Data to Support Ice-Crystal and Mixed-Phase Accretion Testing

This paper describes the imaging techniques as well as the analysis methods used to measure the ice thickness and growth rate in support of ice-crystal icing tests performed at the National Research Council of Canada (NRC) Research Altitude Test Facility (RATFac). A detailed description of the camera setup, which involves both still and video cameras, as well as the analysis methods using the NASA Spotlight software, are presented. Two cases, one from two different test entries, showing significant ice growth are analyzed in detail describing the ice thickness and growth rate which is generally linear. Estimates of the bias uncertainty are presented for all measurements. Finally some of the challenges related to the imaging and analysis methods are discussed as well as methods used to overcome them.

Struk, Peter, M↗

NASA NTRS2012

Ice Growth Measurements from Image Data to Support Ice Crystal and Mixed-Phase Accretion Testing

This paper describes the imaging techniques as well as the analysis methods used to measure the ice thickness and growth rate in support of ice-crystal icing tests performed at the National Research Council of Canada (NRC) Research Altitude Test Facility (RATFac). A detailed description of the camera setup, which involves both still and video cameras, as well as the analysis methods using the NASA Spotlight software, are presented. Two cases, one from two different test entries, showing significant ice growth are analyzed in detail describing the ice thickness and growth rate which is generally linear. Estimates of the bias uncertainty are presented for all measurements. Finally some of the challenges related to the imaging and analysis methods are discussed as well as methods used to overcome them.

Struk, Peter M.↗

NASA NTRS2015

Development of an Infrared Lamp Array for the Smap Spacecraft Thermal Balance Test

NASA launched the SMAP observatory in January 2015 aboard a Delta II into a sun-synchronous orbit around Earth. The science payload of a radar and a radiometer utilizes a shared rotating six-meter antenna to provide a global map of the Earth's soil moisture content and its freeze/thaw state on a global, high-resolution scale in this three-year mission. An observatory-level thermal balance test conducted in May/June 2014 validated the thermal design and demonstrated launch readiness as part of the planned environmental test campaign. An infrared lamp array was designed and used in the thermal balance test to replicate solar heating on the solar array and sunlit side of the spacecraft that would normally be seen in orbit. The design, implementation, and operation of an infrared lamp array used for this nineteen-day system thermal test are described in this paper. Instrumental to the smooth operation of this lamp array was a characterization test performed in the same chamber two months prior to the observatory test to provide insight into its array operation and flux uniformity. This knowledge was used to identify the lamp array power settings that would provide the worst case predicted on-orbit fluxes during eclipse, cold, and hot cases. It also showed the lamp array variation when adjustments in flux were needed. Calorimeters calibrated prior to testing determined a relationship between calorimeter temperature and lamp array flux. This allowed the team to adjust the lamp output for the desired absorbed flux on the solar array. Flux levels were within 10% of the desired value at the center of the solar array with an ability to maintain these levels within 5% during steady state cases. All tests demonstrated the infrared lamp array functionality and furthered lamp array understanding for modeling purposes. This method contributed to a high-fidelity environmental simulation, which was required to replicate the extreme on-orbit thermal environments.

Miller, Jennifer R.↗

NASA NTRS2026

QS ATMS Calibration Data Book Government Version: Pre-Launch Version

The Advanced Technology Microwave Sounder (ATMS) SN301 is an instrument onboard the QuickSounder Satellite System, QuickSounder mission (renamed QS). Throughout this document the mission may be referred to as QuickSounder or QS. The purpose of this document is to provide information needed to interpret and process QS ATMS science data. The contents of the data book incorporate results from pre-launch subsystem-level and instrument-level testing as well as post-launch testing performed during instrument commissioning. Major milestones include instrument thermal vacuum (TVAC) testing in May 2024 and observatory TVAC testing in 2026. QS launch will be no earlier than Feb. 15, 2027.

Microwave Radiometer↗

DOE OSTI2013

Characterization and Potential Remediation Approaches for Vadose Zone Contamination at Hanford 241-SX Tank Farm

Unplanned releases of radioactive and hazardous wastes have occurred at the 241-SX Tank Farm on the U.S. Department of Energy Hanford Site in southeast Washington State. Interim and long-term mitigation efforts are currently under evaluation for 241-SX Tank Farm. Two contiguous interim surface barriers have been designed for deployment at 241-SX Tank Farm to reduce future moisture infiltration; however, construction of the surface barriers has been deferred to allow testing of alternative technologies for soil moisture reduction and possibly contaminant source term reduction. Previous tests performed by other organizations at the Hanford Site have demonstrated that: vadose zone desiccation using large diameter (greater than 4 inch) boreholes is feasible; under certain circumstances, mobile contaminants may be removed in addition to water vapor; and small diameter (approximately 2 inch) boreholes (such as those placed by the direct push hydraulic hammer) can be used to perform vapor extractions. Evaluation of the previous work combined with laboratory test results have led to the design of a field proof-of-principle test to remove water and possibly mobile contaminants at greater depths, using small boreholes placed with the direct push unit.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2014

Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications

Air Products is carrying out a scope of work under DOE Award No. DE-FE0012065 “Development of ITM Oxygen Technology for Low-cost and Low-emission Gasification and Other Industrial Applications.” The Statement of Project Objectives (SOPO) includes a Task 4f in which a Decision Point shall be reached, necessitating a review of Tasks 2-5 with an emphasis on Task 4f. This Topical Report constitutes the Decision Point Application pertaining to Task 4f. The SOPO under DOE Award No. DE-FE0012065 is aimed at furthering the development of the Ion Transport Membrane (ITM) Oxygen production process toward a demonstration scale facility known as the Oxygen Development Facility (ODF). It is anticipated that the completion of the current SOPO will advance the technology significantly along a pathway towards enabling the design and construction of the ODF. Development progress on several fronts is critical before an ODF project can commence; this Topical Report serves as an early update on the progress in critical development areas. Progress was made under all tasks, including Materials Development, Ceramic Processing Development, Engineering Development, and Performance Testing. Under Task 4f, Air Products carried out a cost and performance study in which several process design and cost parameters were varied and assessed with a process model and budgetary costing exercise. The results show that the major variables include ceramic module reliability, ITM operating temperature, module production yield, and heat addition strategy. High-temperature compact heat exchangers are shown to contribute significant cost benefits, while directly firing into the feed stream to an ITM are even a mild improvement on the high-temperature recuperation approach. Based on the findings to-date, Air Products recommends no changes to the content or emphasis in the current SOPO and recommends its completion prior to another formal assessment of these factors.

Armstrong, Phillip↗

DOE OSTI2022

Evaluation of Bifacial Modules and PV Technologies with Combined-Accelerated Stress Testing

In view of the increasing interest and market share of bifacial cells and modules, suitable substrates such as glass and transparent backsheets along with ethylene vinyl acetate (EVA) and polyolefin elastomer (POE) encapsulants were examined in combined-accelerated stress testing (C-AST) to evaluate and compare degradation modes. Testing with both monofacial and bifacial cells, we found glass-glass modules with monofacial cells led to greater grid finger breakage than those with polymeric backsheets. This is attributed to previous x-ray topography work showing higher stress in cells in glass-glass modules than glass backsheet modules. Consistent with the objectives of C-AST, which stresses modules at levels corresponding to the limits seen in the natural environment, we observed the UV-fluorescence signatures of modules tested in C-AST (considering the degradation associated with developing chromophores, moisture penetration and photobleaching effects) to be like those in fielded modules, more so than other chamber stress testing implemented for comparison. Finally, among multiple cell degradation modes that we observed such as light-induced degradation (LID), we differentiated susceptibility to potential-induced degradation (PID) on the back of the bifacial Passivated Emitter Back Cells (PERC) in C-AST. Confirming with ex-situ tests, we found polarization-type PID most prevalent in glass/glass modules with EVA as would be anticipated considering the greater leakage current through such module encapsulation. Unlike PID tests performed in the dark, which can lead to false positive PID test results, field-representative illumination is experienced by the modules on the front and back side while -1200 V system voltage is applied in C-AST, supporting the conclusion that this module type would be susceptible to PID in the field.

bifacial modules↗

DOE OSTI2013

Characterization and Potential Remediation Approaches for Vadose Zone Contamination at Hanford 241-SX Tank Farm - 13235

Unplanned releases of radioactive and hazardous wastes have occurred at the 241-SX Tank Farm on the U.S. Department of Energy Hanford Site in southeast Washington State. Interim and long-term mitigation efforts are currently under evaluation for 241-SX Tank Farm. Two contiguous interim surface barriers have been designed for deployment at 241-SX Tank Farm to reduce future moisture infiltration; however, construction of the surface barriers has been deferred to allow testing of alternative technologies for soil moisture reduction and possibly contaminant source term reduction. Previous tests performed by other organizations at the Hanford Site have demonstrated that: vadose zone desiccation using large diameter (greater than 4 inch) boreholes is feasible; under certain circumstances, mobile contaminants may be removed in addition to water vapor; and small diameter (approximately 2 inch) boreholes (such as those placed by the direct push hydraulic hammer) can be used to perform vapor extractions. Evaluation of the previous work combined with laboratory test results have led to the design of a field proof-of-principle test to remove water and possibly mobile contaminants at greater depths, using small boreholes placed with the direct push unit. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS2017

Development and Testing of a Friction-Based Post-Installable Fiber-Optic Monitoring System for Subsea Applications

This paper presents the design and development of a friction-based coupling device for a fiber-optic monitoring system capable of measuring pressure, strain, and temperature that can be deployed on existing subsea structures. A summary is provided of the design concept, prototype development, prototype performance testing, and subsequent design refinements of the device. The results of laboratory testing of the first prototype performed at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) are also included. Limitations of the initial concept were identified during testing and future design improvements were proposed and later implemented. These new features enhance the coupling of the sensor device and improve the monitoring system measurement capabilities. A major challenge of a post-installed instrumentation monitoring system is to ensure adequate coupling between the instruments and the structure of interest for reliable measurements. Friction-based devices have the potential to overcome coupling limitations caused by marine growth and soil contamination on flowlines, risers, and other subsea structures. The work described in this paper investigates the design and test of a friction-based coupling device (herein referred to as a friction clamp) which is suitable for pipelines and structures that are suspended in the water column as well as for those that are resting on the seabed. The monitoring elements consist of fiberoptic sensors that are bonded to a stainless steel clamshell assembly with a high-friction surface coating. The friction clamp incorporates a single hinge design to facilitate installation of the clamp and dual rows of opposing fasteners to distribute the clamping force along the structure. The friction clamp can be modified to be installed by commercial divers in shallow depths or by remotely operated vehicles in deep-water applications. NASA-JSC was involved in the selection and testing of the friction coating, and in the design and testing of the prototype clamp device. Four-inch diameter and eight-inch diameter sub-scale friction clamp prototypes were built and tested to evaluate the strain measuring capabilities of the design under different loading scenarios. The testing revealed some limitations of the initial design concept, and subsequent refinements were explored to improve the measurement performance of the system. This study was part of a collaboration between NASA-JSC and Astro Technology Inc. within a study called Clear Gulf. The primary objective of the Clear Gulf study is to develop advanced instrumentation technologies that will improve operational safety and reduce the risk of hydrocarbon spillage. NASA provided unique insights, expansive test facilities, and technical expertise to advance technologies that will benefit the environment, the public, and commercial industries.

Bentley, Nicole L.↗

DOE OSTI2012

Integrated Data Collection Analysis (IDCA) Program - Final Review September 12, 2012 at DHS

The Integrated Data Collection Analysis (IDCA) program conducted a final program review at the Department of Homeland Security on September 12, 2012. The review was focused on the results of the program over the complete performance period. A summary presentation delineating the accomplished tasks started the meeting, followed by technical presentations on various issues that arose during the performance period. The presentations were completed with a statistical evaluation of the testing results from all the participants in the IDCA Proficiency Test study. The meeting closed with a discussion of potential sources of funding for continuing work to resolve some of these technical issues. This effort, funded by the Department of Homeland Security (DHS), put the issues of safe handling of these materials in perspective with standard military explosives. The study added Small-Scale Safety and Thermal (SSST) testing results for a broad suite of different HMEs to the literature, and suggested new guidelines and methods to develop safe handling practices for HMEs. Each participating testing laboratory used identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results were compared among the laboratories and then compared to historical data from various sources. The testing performers involved were Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Naval Surface Warfare Center, Indian Head Division (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory, Tyndall AFB (AFRL/RXQL). These tests were conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1979

Indoor test for thermal performance of the Sunmaster evacuated tube (liquid) solar collector

The test procedures used to obtain the thermal performance data for a solar collector under simulated conditions are presented. Tests included a stagnation test, a time constant test, a thermal efficiency test, an incident angle modifier test, and a hot fill test. All tests were performed at ambient conditions and the transient effect and the incident angle effect on the collector were determined. The solar collector is a water working fluid type.

Source record↗

NASA NTRS1976

Viking mission support

On April 26, 1976, the network operations control center was declared available for planetary operations in support of the Viking project. This final capability in the network configuration for Viking had been delayed since February with hardware and software problems both in the control center and at the Deep Space stations. The effect of these problems, particularly insofar as they affected production of intermediate data records, the resolution of the problems, and the current status of the network operations control center in the Viking environment, are given in this article. Also discussed are the operational verification tests performed to check out the new capabilities and associated procedures. The Viking project tests supported by the DSN and finally the DSN support of Viking cruise operations, along with some statistics on performance, are included.

Mudgway, D. J.↗

NASA NTRS1984

Performance Measures for Aircraft Landings as a Function of Aircraft Dynamics

A theory of performance measurement for operator controlled systems is presented. The theory permits synthesis of a system performance measure which scores performance on successive data samples based on the impact of the sampled performance on the overall summary of performance. The development of measures for aircraft carrier landings for the glide path and angle of attack control channels is documented. While developing the performance measures, the measures used previously were evaluated and were found to lack the necessary discrimination capability. The previously used measure, the RMS of deviations from the glide path, can, for instance, provide identical scores for both satisfactory and unsatisfactory flight paths. Two types of performance measures developed for aircraft landings are described. Also, an argument is given for the need to test performance measures prior to their use. A suggested test of the measures is offered.

Connelly, E. M.↗

NASA NTRS1992

Orbital Transfer Vehicle Engine Technology High Velocity Ratio Diffusing Crossover

High speed, high efficiency head rise multistage pumps require continuous passage diffusing crossovers to effectively convey the pumped fluid from the exit of one impeller to the inlet of the next impeller. On Rocketdyne's Orbital Transfer Vehicle (OTV), the MK49-F, a three stage high pressure liquid hydrogen turbopump, utilizes a 6.23 velocity ratio diffusing crossover. This velocity ratio approaches the diffusion limits for stable and efficient flow over the operating conditions required by the OTV system. The design of the high velocity ratio diffusing crossover was based on advanced analytical techniques anchored by previous tests of stationary two-dimensional diffusers with steady flow. To secure the design and the analytical techniques, tests were required with the unsteady whirling characteristics produced by an impeller. A tester was designed and fabricated using a 2.85 times scale model of the MK49-F turbopumps first stage, including the inducer, impeller, and the diffusing crossover. Water and air tests were completed to evaluate the large scale turbulence, non-uniform velocity, and non-steady velocity on the pump and crossover head and efficiency. Suction performance tests from 80 percent to 124 percent of design flow were completed in water to assess these pump characteristics. Pump and diffuser performance from the water and air tests were compared with the actual MK49-F test data in liquid hydrogen.

Lariviere, Brian W.↗

NASA NTRS1987

Miniature high stability high temperature space rated blackbody radiance source

This paper presents the design and test performance of a conical cavity type blackbody radiance source that will meet the requirements of the Halogen Occultation Experiment on the NASA Upper Atmospheric Research Satellite program. The thrust of this design effort was to minimize the heat losses, in order to keep the power usage under 7.5 watts, and to minimize the amount of silica in the materials. Silica in the presence of the platinum heater winding used in this design would cause the platinum to erode, changing the operating temperature set-point. The design required the development of fabrication techniques which would provide very small, close tolerance parts from extremely difficult-to-machine materials. Also, a space rated ceramic core and unique, low thermal conductance, ceramic-to-metal joint was developed, tested and incorporated in this design. The completed flight qualification hardware has undergone performance, environmental and life testing. The design configuration and test results are discussed in detail.

Jones, J. A.↗