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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 163 records · Page 9

STOL and STOVL hot gas ingestion and airframe heating tests in the NASA Lewis 9- by 15-foot low-speed wind tunnel

Short takeoff and landing (STOL) and advanced short takeoff and vertical landing (STOVL) aircraft are being pursued for deployment near the end of this century. These concepts offer unique capabilities not seen in conventional aircraft: for example, shorter takeoff distances and the ability to operate from damaged runways and remote sites. However, special technology is critical to the development of this unique class of aircraft. Some of the real issues that are associated with these concepts are hot gas ingestion and airframe heating while in ground effects. Over the past nine years, NASA Lewis Research Center has been involved in several cooperative programs in the 9- by 15 Foot Low-Speed Wind Tunnel (LSWT) to establish a database for hot gas ingestion and airframe heating. The modifications are presented that were made in the 9- by 15-Foot LSWT, including the evolution of the ground plane, model support system, and tunnel sidewalls; and flow visualization techniques, instrumentation, test procedures, and test results. The 9- by 15-Foot LSWT tests were conducted at full scale exhaust nozzle pressure ratios. The headwind velocities varied from 8 to 120 kn depending on the concept (STOL or STOVL). Typical compressor-face distortions (pressure and temperature), ground plane contours, and model surface temperature profiles are presented.

Johns, Albert L.↗

Photovoltaic array space power plus diagnostics experiment

The objective is to summarize the five years of hardware development and fabrication represented by the Photovoltaic Array Space Power Plus Diagnostics (PASP Plus) Instrument. The original PASP Experiment requirements and background is presented along with the modifications which were requested to transform the PASP Experiment into the PASP Plus Instrument. The PASP Plus hardware and software is described. Test results for components and subsystems are given as well as final system tests. Also included are appendices which describe the major subsystems and present supporting documentation such as block diagrams, schematics, circuit board artwork, drawings, test procedures and test reports.

Burger, D. R.↗

Health maintenance facility: Dental equipment requirements

The objectives were to test the effectiveness of the Health Maintenance Facility (HMF) dental suction/particle containment system, which controls fluids and debris generated during simulated dental treatment, in microgravity; to test the effectiveness of fiber optic intraoral lighting systems in microgravity, while simulating dental treatment; and to evaluate the operation and function of off-the-shelf dental handheld instruments, namely a portable dental hand drill and temporary filling material, in microgravity. A description of test procedures, including test set-up, flight equipment, and the data acquisition system, is given.

Young, John↗

Experiments with phase change thermal energy storage canisters for Space Station Freedom

The solar dynamic power module proposed for the Space Station Freedom (SSF) uses the heat of fusion of a phase change material (PCM) to efficiently store thermal energy for use during eclipse periods. The PCM, a LiF-20CaF2 salt, is contained in annular, metal canisters located in a heat receiver at the focus of a solar concentrator. PCM canister ground-based experiments and analytical heat transfer studies are discussed. The hardware, test procedures, and test results from these experiments are discussed. After more than 900 simulated SSF orbital cycles, no canister cracks or leaks were observed and all data were successfully collected. The effect of 1-g test orientation on canister wall temperatures was generally small while void position was strongly dependent on test orientation and canister cooling. In one test orientation, alternating wall temperature data were measured that supports an earlier theory of oscillating vortex flow in the PCM melt. Analytical canister wall temperatures compared very favorably with experimental temperature data. This illustrates that ground-based canister thermal performance can be predicted well by analyses that employ straight-forward, engineering models of void behavior and liquid PCM free convection.

Kerslake, Thomas W.↗

Arc tracking of cables for space applications

The main objective of this study is to develop a new test method that is suitable for the assessment of the resistance of aerospace cables to arc tracking for different specific environmental and network conditions of spacecrafts. This paper reports the purpose, test conditions, test specimen, test procedure, and test acceptance criteria of seven different (200-250 mm long) cables.

Koenig, D.↗

The Third Flight Magnet

A self-shielded superconducting magnet was designed for the NASA Goddard Space Flight Center Adiabatic Demagnetization Refrigerator Program. This is the third magnet built from this design. The magnets utilize Cryomagnetics' patented ultra-low current technology. The magnetic system is capable of reaching a central field of two tesla at slightly under two amperes and has a total inductance of 1068 henries. This final report details the requirements of the magnet, the specifications of the resulting magnet, the test procedures and test result data for the third magnet (Serial # C-654-M), and recommended precautions for use of the magnet.

McGhee, R. Wayne↗

Procedure Developed for Ballistic Impact Testing of Composite Fan Containment Concepts

The fan-containment system in a jet engine is designed to prevent a fan blade from penetrating the engine case in the event that the blade or a portion of the blade separates from the rotor during operation. Usually, these systems consist of a thick metal case that is strong enough to survive such an impact. Other systems consist of a dry aramid fabric wrapped around a relatively thin metal case. In large turbofan engines, metal-containment systems can weigh well over 300 kg, and there is a strong impetus to reduce their weight. As a result, the NASA Lewis Research Center is involved in an effort to develop polymer matrix composite (PMC) fan-containment systems to reduce the weight and cost while maintaining the high levels of safety associated with current systems. Under a Space Act Agreement with AlliedSignal Aircraft Engines, a new ballistic impact test procedure has been developed to quantitatively evaluate the performance of polymer matrix composite systems.

Pereira, J. Michael↗

Prevailing Torque Locking Feature in Threaded Fasteners Using Anaerobic Adhesive

This paper presents results from tests to assess the use of anaerobic adhesive for providing a prevailing torque locking feature in threaded fasteners. Test procedures are developed and tests are performed on three fastener materials, four anaerobic adhesives, and both unseated assembly conditions. Five to ten samples are tested for each combination. Tests for initial use, reuse without additional adhesive, and reuse with additional adhesive are performed for all samples. A 48-hour cure time was used for all initial use and reuse tests. Test data are presented as removal torque versus removal angle with the specification required prevailing torque range added for performance assessment. Percent specification pass rates for the all combinations of fastener material, adhesive, and assembly condition are tabulated and reveal use of anaerobic adhesive as a prevailing torque locking feature is viable. Although not every possible fastener material and anaerobic adhesive combination provides prevailing torque values within specification, any combination can be assessed using the test procedures presented. Reuse without additional anaerobic adhesive generally provides some prevailing torque, and in some cases within specification. Reuse with additional adhesive often provides comparable removal torque data as in initial use.

Hernandez, Alan↗

Standardization of carbon-phenolic composite test methodology

The objective of this study was to evaluate the residual volatiles, filler content, and resin flow test procedures for carbon-phenolic prepreg materials. The residual volatile test procedure was rewritten with tighter procedure control which was then evaluated by round robin testing by four laboratories on the same rolls of prepreg. Results indicated that the residual volatiles test was too operator and equipment dependent to be reliable, and it was recommended that the test be discontinued. The resin flow test procedures were rewritten with tighter procedure control, and it is now considered to be an acceptable test. It was recommended that the filler content determination be made prior to prepregging.

Hall, W. B.↗

Sizing Single Cantilever Beam Specimens for Characterizing Facesheet/Core Peel Debonding in Sandwich Structure

This technical publication details part of an effort focused on the development of a standardized facesheet/core peel debonding test procedure. The purpose of the test is to characterize facesheet/core peel in sandwich structure, accomplished through the measurement of the critical strain energy release rate associated with the debonding process. Following an examination of previously developed tests and a recent evaluation of a selection of these methods, a single cantilever beam (SCB) specimen was identified as being a promising candidate for establishing such a standardized test procedure. The objective of the work described here was to begin development of a protocol for conducting a SCB test that will render the procedure suitable for standardization. To this end, a sizing methodology was developed to ensure appropriate SCB specimen dimensions are selected for a given sandwich system. Application of this method to actual sandwich systems yielded SCB specimen dimensions that would be practical for use. This study resulted in the development of a practical SCB specimen sizing method, which should be well-suited for incorporation into a standardized testing protocol.

Ratcliffe, James G.↗

On the Crack Bifurcation and Fanning of Crack Growth Data

Crack growth data obtained from ASTM load shedding method for different R values show some fanning especially for aluminum alloys. It is believed by the authors and it has been shown before that the observed fanning is due to the crack bifurcation occurs in the near threshold region which is a function of intrinsic properties of the alloy. Therefore, validity of the ASTM load shedding test procedure and results is confirmed. However, this position has been argued by some experimentalists who believe the fanning is an artifact of the test procedure and thus the obtained results are invalid. It has been shown that using a special test procedure such as using compressively pre-cracked specimens will eliminate the fanning effect. Since not using the fanned data fit can result in a significantly lower calculated cyclic life, design of a component, particularly for rotorcraft and propeller systems will considerably be impacted and therefore this study is of paramount importance. In this effort both test procedures i.e. ASTM load shedding and the proposed compressive pre-cracking have been used to study the fatigue crack growth behavior of compact tension specimens made of aluminum alloy 2524-T3. Fatigue crack growth paths have been closely observed using SEM machines to investigate the effects of compression pre-cracking on the crack bifurcation behavior. The results of this study will shed a light on resolving the existing argument by better understanding of near threshold fatigue crack growth behavior.

Forman, Royce G.↗

Integrated Advanced Microwave Sounding Unit-A (AMSU-A. Engineering Report: Electromagnetic Interface (EMI)/Electromagnetic Radiation (EMR) and Electromagnetic Compatibility (EMC), for the METSAT/METOP AMSU-A1

This document contains the procedure and the test results of the Advanced Microwave Sounding Unit-A (AMSU-A) Electromagnetic Interference (EMI), Electromagnetic Susceptibility, and Electromagnetic Compatibility (EMC) qualification test for the Meteorological Satellite (METSAT) and the Meteorological Operation Platform (METOP) projects. The test was conducted in accordance with the approved EMI/EMC Test Plan/Procedure, Specification number AE-26151/5D. This document describes the EMI/EMC test performed by Aerojet and it is presented in the following manner: Section-1 contains introductory material and a brief summary of the test results. Section 2 contains more detailed descriptions of the test plan, test procedure, and test results for each type of EMI/EMC test conducted. Section 3 contains supplementary information that includes test data sheets, plots, and calculations collected during the qualification testing.

Valdez, A.↗

Turbine blade testing methods

Testing procedures which could be used to model test turbine blades are developed. The methods studied were methods which used and extended current modal testing procedures. An acoustical impacting testing method was perfected for testing small turbine blades.

Source record↗

Marshall Space Flight Center head development program

This report summarizes the results of the candidate head evaluation for the new long-life magnetic head per the SOW of Contract No. NAS8-39407, MSFC Head Development Program. The original program plans were to test a candidate head, fabricate a new head, then qualify the new head. These activities were scheduled to be carried out between March 1993 and March 1994. The program was halted after the evaluation of the candidate head by NAS8-39407 Amendment No. 4. MSFC has provided and authorized the use the MARS-2000 SRB QUAL Recorder PN 10400-0677-801 - Serial Number 200004 (Datatape PN 591000 - Serial Number 1004), Reproduce Amplifier Module (RAM) Datatape PN 533040 - Serial Number 2006, associated cables, and magnetic tape on special SRB/DFI tapered reels to Datatape for this program. All the testing that has been done for the candidate head evaluation was done at Datatape's facility in Pasadena,CA. The testing was performed in a Class 100,000 particle counts clean room at ambient temperature, except for the thermal testing which was conducted in a different area at Datatape. The Performance Verification Test Procedure PVT-11004-4 (PVT) and Acceptance Test Procedure ATP-11004-09 (ATP) procedures were used when tests were conducted on the recorder.

Harrer, Jim↗

Guidelines for Broadband Seismometer Testing

The Comprehensive Nuclear-Test-Ban Treaty mandates the four verification technologies to be used by the International Monitoring System (IMS) to monitor compliance to the Treaty. These technologies are seismic, hydroacoustic, infrasound, and radionuclide. Operational manuals for each of these technologies specify the requirements that equipment installed at IMS stations must meet for data from said stations to be accepted by the International Data Center. Following a model in which a revised set of infrasound sensor specifications and accompanying test procedures were developed in an international collaboration overseen by the Comprehensive Nuclear-Test-Ban Treaty Organization, the same process was recently followed for seismometers potentially of use by the IMS. This document, a product of that collaboration, defines key concepts and recommends test procedures to be followed to characterize broadband seismometers in a consistent and standardized way. Results from these test procedures can be used to verify that a seismometer meets the manufacturers stated specifications and IMS requirements. ACKNOWLEDGEMENTS The writers of this document would like to acknowledge Charles R. Hutt, John R. Evans, Fred Followill, Robert L. Nigbor, and Erhard Wielandt, the authors of the 2009 Guidelines for Standardized Testing of Broadband Seismometers and Accelerometers funded by the U.S. Department of Interior, on which this document is based. Although this document is limited in scope to seismometers and much of the document has been updated, the structure remains essentially the same.

58 GEOSCIENCES↗

Plug-in electric vehicles in China and the USA: a technology and market comparison

As the top two plug-in electric vehicle (PEV) markets in the world, China and the United States of America (USA) have developed different market structures that are influenced by government policies, test procedures, customer acceptance, and vehicle performance. There are differences in PEV test procedures and vehicle class definitions as well. This paper quantifies such differences and compares PEV characteristics and markets in the two countries using actual data collected over several years. First, although China surpasses the USA in annual PEV production because of generous PEV policies and higher charging infrastructure availability, the USA has a higher PEV adoption rate per capita (2.3 versus 0.81 per 1000 people at the end of 2017). Second, the most popular vehicle classes are A00 battery electric vehicles (BEVs) in China but long-range mid-size BEVs in the USA. Moreover, China's electric and plug-in hybrid sport utility vehicle market is growing quickly. Third, the electricity consumption rated under Chinese test procedures is 20%-40% lower than that rated under US procedures. The sales-weighted electricity consumption of an average BEV in China is 23% lower than that in the USA because of larger proportions of small and micro BEVs in China. Fourth, PEV battery cost in the two countries is currently close to $210-$220 kWh. Finally, China has higher numbers of charging infrastructure, and the ratio of PEVs to public chargers is 9.0 in China versus 17.9 in the USA at the end of 2018.

China EV market↗

Sizing Single Cantilever Beam Specimens for Characterizing Facesheet/Core Peel Debonding in Sandwich Structure

This paper details part of an effort focused on the development of a standardized facesheet/core peel debonding test procedure. The purpose of the test is to characterize facesheet/core peel in sandwich structure, accomplished through the measurement of the critical strain energy release rate associated with the debonding process. The specific test method selected for the standardized test procedure utilizes a single cantilever beam (SCB) specimen configuration. The objective of the current work is to develop a method for establishing SCB specimen dimensions. This is achieved by imposing specific limitations on specimen dimensions, with the objectives of promoting a linear elastic specimen response, and simplifying the data reduction method required for computing the critical strain energy release rate associated with debonding. The sizing method is also designed to be suitable for incorporation into a standardized test protocol. Preliminary application of the resulting sizing method yields practical specimen dimensions.

Ratcliffe, James G.↗

Development of Optical Step Height Measurement Capability for the BOLT Flight Vehicle

This paper presents details on the development of testing procedures to evaluate two different optical step height sensors that were intended for use on the first and second Boundary Layer Transition (BOLT and BOLT II) flight vehicle as well as other flight vehicles. The accurate and precise measurement of step height at the interface of different sections of a flight vehicle is important, as small changes in the step height (in some instances < 10 microns) at such locations can have a significant influence on the development of a boundary layer over the outer surface of the vehicle, which in turn can significantly impact aeroheating (among other things). In this paper, testing procedures have been developed, and test hardware assembled, to determine the capabilities of two optical step height sensor candidates. The first candidate is a miniaturized camera sensor that would be embedded into the body of a flight vehicle and would image the interface between two sections of that vehicle. The second candidate is a small fiber-based optical sensor that would also be embedded into the body of the flight vehicle, but projects light onto the interface between two sections of the flight vehicle, and then monitors any reflected/scattered light from that interface. Preliminary data from these two sensor candidates are presented, and a discussion of improvements that will be made in the testing procedures and to the test hardware is provided.

Brett F Bathel↗