SEARCH · Engineering Papers

Results for “testing data”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,693 records · Page 94

All sources NASA NTRS DOE OSTI

NASA NTRS1935

The Effect of the Angle of Afterbody Keel on the Water Performance of a Flying-Boat Hull Model

NACA model 11-C was tested according to the general method with the angle of afterbody keel set at five different angles from 2-1/2 degrees to 9 degrees, but without changing other features of the hull. The results of the tests are expressed in curves of test data and of non-dimensional coefficients. At the depth of step used in the tests, 3.3 percent beam, the smaller angles of afterbody keel give greater load-resistance ratios at the hump speed and smaller at high speed than the larger angles of afterbody keel. Comparisons are made of the load-resistance ratios at several other points in the speed range. The effect of variation of the angle of afterbody keel upon the take-off performance of a hypothetical flying boat of 15,000 pounds gross weight having a hull of model 11-C lines is calculated, and the calculations show that the craft with the largest of the angles of afterbody keel tested, 9 degrees, takes off in the least time and distance.

Allison, John M.↗

NASA NTRS1941

Boundary layer removal by suction

Flight-test data and wind-tunnel data on suction profiles are substantially in agreement. The lift values found in the model test can be actually flown and used as a basis for the design. To visualize the action of the suction, the flow conditions with and without suction on the upper surface were photographed; figures 12 to 15 are sections of the film.

Schrenk, O↗

NASA NTRS2000

Integrated Advance Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: EOS AMSU-A1 and AMSU-A2 Receivers Assemblies

This test report presents the test data of the EOS AMSU-A Flight Model No.1 (FM-1) receiver subsystem. The tests are performed per the Acceptance Test Procedure for the AMSU-A Reseiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, the subsystem-level test are conducted at ambient temperature only.

Source record↗

NASA NTRS2002

Software for Statistical Analysis of Weibull Distributions with Application to Gear Fatigue Data: User Manual with Verification

The Weibull distribution has been widely adopted for the statistical description and inference of fatigue data. This document provides user instructions, examples, and verification for software to analyze gear fatigue test data. The software was developed presuming the data are adequately modeled using a two-parameter Weibull distribution. The calculations are based on likelihood methods, and the approach taken is valid for data that include type 1 censoring. The software was verified by reproducing results published by others.

Krantz, Timothy L.↗

NASA NTRS2002

Software for Statistical Analysis of Weibull Distributions with Application to Gear Fatigue Data: User Manual with Verification

The Weibull distribution has been widely adopted for the statistical description and inference of fatigue data. This document provides user instructions, examples, and verification for software to analyze gear fatigue test data. The software was developed presuming the data are adequately modeled using a two-parameter Weibull distribution. The calculations are based on likelihood methods, and the approach taken is valid for data that include type I censoring. The software was verified by reproducing results published by others.

Kranz, Timothy L.↗

NASA NTRS2013

Closeout Report for the Refractory Metal Accelerated Heat Pipe Life Test Activity

With the selection of a gas-cooled reactor, this heat pipe accelerated life test activity was closed out and its resources redirected. The scope of this project was to establish the long-term aging effects on Mo-44.5%Re sodium heat pipes when subjected to space reactor temperature and mass fluences. To date, investigators have demonstrated heat pipe life tests of alkali metal systems up to .50,000 hours. Unfortunately, resources have not been available to examine the effect of temperature, mass fluence, or impurity level on corrosion or to conduct post-test forensic examination of heat pipes. The key objective of this effort was to establish a cost/time effective method to systematically test alkali metal heat pipes with both practical and theoretical benefits. During execution of the project, a heat pipe design was established, a majority of the laboratory test equipment systems specified, and operating and test procedures developed. Procurements for the heat pipe units and all major test components were underway at the time the stop work order was issued. An extremely important outcome was the successful fabrication of an annular wick from Mo-5%Re screen (the single, most difficult component to manufacture) using a hot isostatic pressing technique. This Technical Publication (TP) includes specifics regarding the heat pipe calorimeter water-cooling system, vendor design for the radio frequency heating system, possible alternative calorimeter designs, and progress on the vanadium equilibration technique. The methods provided in this TP and preceding project documentation would serve as a good starting point to rapidly implement an accelerated life test. Relevant test data can become available within months, not years, and destructive examination of the first life test heat pipe might begin within 6 months of test initiation. Final conclusions could be drawn in less than a quarter of the mission duration for a long-lived, fission-powered, deep space probe.

Martin, J.↗

NASA NTRS2013

Human-rated Safety Certification of a High Voltage Robonaut Lithium-ion Battery

NASA's rigorous certification process is being followed for the R2 high voltage battery program for use of R2 on International Space Station (ISS). Rigorous development testing at appropriate levels to credible off-nominal conditions and review of test data led to design improvements for safety at the virtual cell, cartridge and battery levels. Tests were carried out at all levels to confirm that both hardware and software controls work. Stringent flight acceptance testing of the flight battery will be completed before launch for mission use on ISS.

Jeevarajan, Judith↗

NASA NTRS2018

NASA Electronic Parts and Packaging (NEPP) Field Programmable Gate Array (FPGA) Single Event Effects (SEE) Test Guideline Update

The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

Test guidelines↗

NASA NTRS2018

NASA Electronic Parts and Packaging Field Programmable Gate Array Single Event Effects Test Guideline Update

Field Programmable Gate Array (FPGA)↗

NASA NTRS2018

Aerogel-Based Insulation Materials for Cryogenic Applications

Many different aerogel-based materials are now being used in thermal insulation systems for cryogenic applications. These materials include flexible composite blankets, bulk-fill particles, and polymer composites in both evacuated and non-evacuated environments. In ambient environments, aerogels provide superior thermal performance compared to conventional polymeric foam and cellular glass insulations while offering unique advantages in avoiding problems with weathering, moisture, and mechanical damage. Aerogels are also used as spacer materials in multilayer insulation systems. These layered systems provide combined structural-thermal capability for cryogenic systems in either vacuum-jacketed or externally-applied insulation designs. Test data (effective thermal conductivity) include a wide range of both commercial and experimental aerogel materials. Testing was performed using laboratory cryostats and standard methods including full range vacuum (from ambient pressure to high vacuum) and boundary temperatures 293 K and 78 K. Examples of aerogel-based insulation systems are given for both evacuated and non-evacuated applications.

heat transfer↗

NASA NTRS2018

Aerogel-Based Insulation Materials for Cryogenic Applications

Many different aerogel-based materials are now being used in thermal insulation systems for cryogenic applications. These materials include flexible composite blankets, bulk-fill particles, and polymer composites in both evacuated and non-evacuated environments. In ambient environments, aerogels provide superior thermal performance compared to conventional polymeric foam and cellular glass insulations while offering unique advantages in solving problems with weathering, moisture, and mechanical damage. Aerogels are also used as spacer materials in multilayer insulation systems. These layered systems provide combined structural-thermal capability for cryogenic systems in either vacuum-jacketed or externally-applied insulation designs. Test data (effective thermal conductivity) include a wide range of both commercial and experimental aerogel materials. Testing was performed using laboratory cryostats and standard methods including full range vacuum (from ambient pressure to high vacuum) and boundary temperatures 293 K and 78 K. Examples of aerogel-based insulation systems are given for both evacuated and non-evacuated applications.

aerogel layered composites↗

NASA NTRSDate not supplied

MEDLI2: Ablator Models for Flight

During the entry of Mars Science Laboratory (MSL) the heatshield was equipped with the instrumentation suite Mars Entry, Descent, and Landing Instruments (MEDLI). In-depth thermocouple (TC) data was used to reconstruct the surface heating[1,2]. Discrepancies between MEDLI’s flight heating data and predicted thermal response and recession[3] led to a campaign to characterize and test Mars2020 and MEDLI2 (Mars Entry, Descent, and Landing Instrument 2)[4] flight-lot thermal protection materials (TPS) at relevant ground test conditions. This paper covers the development and validation of flight-lot material response models for the heatshield material Phenolic Impregnated Carbon Ablator (PICA) and the backshell material SLA-561V (Super Lightweight Ablator). Virgin and char properties such as thermal conductivity and emissivity were updated as a function of temperature and pressure in the MEDLI2 specific material response models. Other material properties were characterized and determined to be similar to prior TPS material measurements used for the heritage models. MEDLI2 also investigated the impact of the protective coating that was applied to MSL and Mars2020’s PICA heatshield to reduce the particulate matter shedding. Evidence from arc jet experiments on coated PICA showed that although there were no adverse effects on the performance of the TPS, there were differences in the in-depth temperatures and reduced recession compared to material response predictions of uncoated PICA.[5,6]. Fully Implicit Ablation and Thermal response (FIAT)[7] material response simulations were conducted with the heritage and MEDLI2 flight-lot material models. FIAT-predicted in-depth temperature responses and recession predictions were compared to flight-lot certification ground-test arc jet test data and MEDLI2 thermocouple data.

Materials Response↗

NASA NTRSDate not supplied

On Characterization of Laminar to Turbulent Transitional Flow in the Truncated IHF Semi-Elliptical Nozzle

This paper reports computational analysis and experimental data to characterize the laminar to turbulent flow transition in a high-enthalpy panel test facility at NASA Ames Research Center. The recently developed facility configuration uses a truncated version of an existing semi-elliptical nozzle in the 60-MW Interaction Heating Facility, and it provides testing capability for panel test articles as large as 43.2 cm x 43.2 cm (17 in x 17 in). A water-cooled calibration plate, which is attached to the semi-elliptical nozzle bottom surface and instrumented with twenty Gardon-gage heat flux calorimeters and twelve pressure gages, is used to characterize the convective heating environment over the panel test articles. The present analysis comprises computational fluid dynamics simulations of the nonequilibrium flowfield in the facility nozzle and test box, and the flowfields over panel test articles, and comparisons with the measured test data. Both laminar and turbulent simulations are performed. Constant current studies are performed: the measured data are grouped at the same arc current levels with varying mass flow rates, and they are compared with corresponding computations. For all currents studied, these studies indicate that the semi-elliptical nozzle flow is transitional at relatively higher mass flow rates within the facility operating envelope.

Arc-jets↗

NASA NTRSDate not supplied

MEDLI2 Material Response Model Development and Validation

During the entry of Mars Science Laboratory (MSL) the heatshield was equipped with the instrumentation suite Mars Entry, Descent, and Landing Instruments (MEDLI). In-depth thermocouple (TC) data was used to reconstruct the surface heating and temperatures. Discrepancies between MEDLI’s recorded in-depth heating data and the predicted thermal response and recession led to a campaign to characterize and test Mars Entry, Descent, and Landing Instrument 2 (MEDLI2) flight lot thermal protection materials (TPS) at relevant temperatures and pressures for Martian entry conditions. This paper covers the development and validation of MEDLI2 flight lot material response models for the heatshield material Phenolic Impregnated Carbon Ablator (PICA) and the backshell material Super-Lightweight Ablator (SLA-561V). Virgin and char thermal conductivities were updated as a function of temperature and pressure in the MEDLI2 specific material response models. Other material properties such as virgin and char density, emissivity, absorptivity, and specific heat capacitance was also characterized and compared to the “Heritage” models used during the TPS design phase of Mars 2020. Fully Implicit Ablation and Thermal response (FIAT) simulations were completed using the Heritage and MEDLI2 material response models to provide evidence of the increased accuracy of the MEDLI2 model. FIAT predicted in-depth temperatures were compared to flight lot certification ground-test arc jet test data and MEDLI2 flight thermocouple data.

Material response↗

NASA NTRSDate not supplied

On Characterization of Laminar to Turbulent Transitional Flow in the Truncated IHF Semi-Elliptical Nozzle

This paper reports computational analysis and experimental data to characterize the laminar to turbulent flow transition in a high-enthalpy panel test facility at NASA Ames Research Center. The recently developed facility configuration uses a truncated version of an existing semi-elliptical nozzle in the 60-MW Interaction Heating Facility, and it provides testing capability for panel test articles as large as 43.2 cm x 43.2 cm (17 in x 17 in). A water-cooled calibration plate, which is attached to the semi-elliptical nozzle bottom surface and instrumented with twenty Gardon-gage heat flux calorimeters and twelve pressure gages, is used to characterize the convective heating environment over the panel test articles. The present analysis comprises computational fluid dynamics simulations of the nonequilibrium flowfield in the facility nozzle and test box, and the flowfields over panel test articles, and comparisons with the measured test data. Both laminar and turbulent simulations are performed. Constant current studies are conducted: the measured data are grouped at the same arc current levels with varying mass flow rates, and they are compared with corresponding computations. For all currents considered, these studies indicate that the semi-elliptical nozzle flow is transitional at relatively higher mass flow rates within the facility operating envelope. An approximate facility map for the transitional flow characterization is developed, showing laminar and transitional to turbulent flow regions.

Arc-jets↗

NASA NTRSDate not supplied

Flight Performance Maneuver Planning for NASA’s X-57 “Maxwell” Flight Demonstrator – Part 2: Power-On Effects

Distributed Electric Propulsion technology as envisioned for NASA’s X-57 “Maxwell” flight demonstrator concept was designed to increase high-speed cruise efficiency compared to a combustion-powered general aviation baseline. A portion of this increased efficiency was due to beneficial aero-propulsive interaction inherent to the distributed propulsion architecture. The measure of the increase in efficiency between a conventional and distributed propulsion wing was to be determined by comparing flight test data from the electrically powered, conventional wing X-57 Mod II configuration to data obtained from the electrically powered, distributed propulsion wing X-57 Mod III/IV configuration. Flight test maneuvers that accommodate errors in instrumentation and the flight test environment were previously developed to establish the power-off drag characteristics for all X-57 configurations. In this paper, test points and maneuvers are evaluated to establish the installed and gross thrust that build upon the power-off drag estimates. Analysis of the proposed power-on maneuvers shows that the selected test points and measurement techniques could generate installed thrust estimates within 3-7% (at the 50% confidence level) of the actual values if each maneuver is conducted over a time period of 40 seconds.

Nicholas K Borer↗

NASA NTRS1977

Computer assisted thermal-vacuum testing

In testing complex systems and components under dynamic thermal-vacuum environments, it is desirable to optimize the environment control sequence in order to reduce test duration and cost. This paper describes an approach where a computer is utilized as part of the test control operation. Real time test data is made available to the computer through time-sharing terminals at appropriate time intervals. A mathematical model of the test article and environmental control equipment is then operated on using the real time data to yield current thermal status, temperature analysis, trend prediction and recommended thermal control setting changes to arrive at the required thermal condition. The data acquisition interface and the time-sharing hook-up to an IBM-370 computer is described along with a typical control program and data demonstrating its use.

Petrie, W.↗

NASA NTRS1999

International Ultraviolet Explorer (IUE) Battery History and Performance

The "International Ultraviolet Explorer (IUE) Battery History and Performance" report provides the information on the cell/battery design, battery performance during the thirty eight (38) solar eclipse seasons and the end-of-life test data. It is noteworthy that IUE spacecraft was an in-house project and that the batteries were designed, fabricated and tested (Qualification and Acceptance) at the Goddard Space Flight Center. A detailed information is given on the cell and battery design criteria and the designs, on the Qualification and the Acceptance tests, and on the cell life cycling tests. The environmental, thermal, and vibration tests were performed on the batteries at the battery level as well as with the interface on the spacecraft. The telemetry data were acquired, analyzed, and trended for various parameters over the mission life. Rigorous and diligent battery management programs were developed and implemented from time to time to extend the mission life over eighteen plus years. Prior to the termination of spacecraft operation, special tests were conducted to check the battery switching operation, battery residual capacity, third electrode performance and battery impedance.

Rao, Gopalskrishna M.↗