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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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A real time mission simulation test program of nickel cadmium cells, performed in conjunction with the Anik 1A2 satellite, is reviewed. Simulation of the temperature profiles, the electrical profiles, the depth of discharge, and the rate of charge and discharge is reported. The type of separator used in the cells and the transfer of electrolytes during overcharge are discussed.
Test results for FM 5055B Lot No. 1 for filler testing, resin testing, fabric testing, and prepreg testing are presented in tabular and graphic format.
Test results for FM 5055B Lot No. 3 for filler testing, resin testing, fabric testing, and prepreg testing are presented in tabular and graphic format.
Test results for FM 5839 Lot No. 4 for filler testing, resin testing, fabric testing, prepreg testing are presented in tabular and graphic format.
The heat-transfer characteristics of a chordwise-finned, impingement-cooled vane were investigated in both a modified J-57 research engine and a four-vane cascade. The data were compared by a correlation of temperature difference ratio with coolant- to gas-flow ratio and also by two modifications of this correlation. The results indicated that the cascade vane temperature data can generally be used to represent the engine vane temperature data. A discussion of engine and cascade gas-side heat-transfer coefficients is also presented. A redesign of the vane leading edge could significantly increase the potential turbine-inlet temperature operating limit.
Analysis of C-141A flight test drag data
Advanced Flexible Reusable Surface Insulation (AFRSI) was developed as a replacement for the low-temperature (white) tiles on the Space Shuttle. The first use of the AFRSI for an Orbiter flight was on the OMS POD of Orbiter (OV-099) for STS-6. Post flight examination after STS-6 showed that damage had occurred to the AFRSI during flight. The failure anomaly between previous wind-tunnel tests and STS-6 prompted a series of additional wind tunnel tests to gain an insight as to the cause of the failure. An assessment of all the past STS-6 wind tunnel tests pointed out the sensitivity of the test results to scaling of dynamic loads due to the difference of boundary layer thickness, and the material properties as a result of exposure to heating. The thread component of the AFRSI was exposed to fatigue testing using an apparatus that applied pulsating aerodynamic loads on the threads similar to the loads caused by an oscillating shock. Comparison of the mean values of the number-of-cycles to failure showed that the history of the thread was the major factor in its performance. The thread and the wind tunnel data suggests a mechanism of failure for the AFRSI.
This Final Report presents an overview of the impact tests performed at NASA/MSFC in the time period 1985 to 1991 and the results of phenomena repeatability and data uncertainty studies performed using the information obtained from those tests. An analysis of the data from over 400 tests conducted between 1989 and 1991 was performed to generate a database to supplement the Hypervelocity Impact Damage Database developed under a previous effort.
This file contains the first set of tracer data for the EGS Collab testbed. The first set of tracer tests were conducted during October-November, 2018. We have included tracer data for C-dots, chloride, fluorescein, and rhodamine-B. The details about the tracer test can be found in Background and Methods of Tracer Tests (Mattson et al. (2019)) (also included in this package). References Mattson, E.D., Neupane, G., Plummer, M.A., Hawkins, A., Zhang, Y. and the EGS Collab Team 2019. Preliminary Collab fracture characterization results from flow and tracer testing efforts. In Proceedings 44th Workshop on Geothermal Reservoir Engineering, edited, Stanford University, Stanford, California.
The Advanced Flexible Reusable Surface Insulation (AFRSI) test article was wind tunnel tested. The AFRSI was exposed to a simulated ascent airloads environment and data was obtained which could be used to support the AFRSI certification program. The AFRSI sequence of environments also included radiant heating (1500 degrees Fahrenheit) and wind/rain environments. The test article was wind/rain conditioned before each wind tunnel entry and was thermally conditioned after each wind tunnel entry. The AFRSI failed and the test was aborted before reaching the ascent environment. The AFRSI test article sequentially exposed to 50 wind/rain and 49 simulated entry thermal missions, as well as four wind tunnel entries equivalent to 40 ascent missions.
ABSTRACT For topical, dermatological drug products, an in vitro option to determine bioequivalence (BE) between test and reference products is recommended. In particular, in vitro permeation test (IVPT) data analysis uses a reference‐scaled approach for two primary endpoints, cumulative penetration amount (AMT) and maximum flux ( J max ), which takes the within donor variability into consideration. In 2022, the Food and Drug Administration (FDA) published a draft IVPT guidance that includes statistical analysis methods for both balanced and unbalanced cases of IVPT study data. This work presents a comprehensive evaluation of various methodologies used to estimate critical parameters essential in assessing BE. Specifically, we investigate the performance of the FDA draft IVPT guidance approach alongside alternative empirical and model‐based methods utilizing mixed‐effects models. Our analyses include both simulated scenarios and real‐world studies. In simulated scenarios, empirical formulas consistently demonstrate robustness in approximating the true model, particularly in effectively addressing treatment–donor interactions. Conversely, the effectiveness of model‐based approaches heavily relies on precise model selection, which significantly influences their results. The research emphasizes the importance of accurate model selection in model‐based BE assessment methodologies. It sheds light on the advantages of empirical formulas, highlighting their reliability compared to model‐based approaches and offers valuable implications for BE assessments. Our findings underscore the significance of robust methodologies and provide essential insights to advance their understanding and application in the assessment of BE, employed in IVPT data analysis.
The system concepts and the flight test program results for a NASA designed in-flight data acquisition system are described. The system draws power from a rechargeable battery pack and intrudes on the aircraft systems only with a total pressure probe, a static pressure probe, and control position transducers, which are simply taped to the frame. A 4000 byte microcomputer forms the heart of the data recording system for cassette tape storage, and is expansion coupled to an eight-bit interactive microcomputer which interfaces with a transducer package for 16-channel demultiplexing. The transducers, ranges, and accuracies are listed, and a five/sec data acquisition rate minimum requirement is noted, although a 10/sec rate is used. The system components are detailed, along with the control and data processing procedures, and the results of dynamic flight testing are presented.
Sequence E: Yaw Releases (P) This test sequence used a downwind, rigid turbine with a 3.4° cone angle. The wind speeds ranged from 7 m/s to 17 m/s. Initial yaw angles of ±90° were achieved. The blade tip pitch was 3°. The rotor rotated at 72 RPM. Blade and probe pressure measurements were collected. The teeter dampers were replaced with rigid links, and these two channels were flagged as not applicable by setting the measured values in the data file to –99999.99 Nm. The teeter link load cell was pre-tensioned to 40,000 N. The turbine was positioned at each specified yaw angle. A 30- second data set was collected with the yaw brake engaged. These points used a letter for the last digit beginning with A and proceeding through the alphabet as repeat points were needed. These points were plotted and compared to ascertain the functionality of the instrumentation. The files ending in numbers beginning with 0 and increasing with each repetition represent yaw release points. Once the fixed-position yaw test was complete, the yaw drive was engaged to hold the turbine. The yaw brake was released, and the yaw drive was disabled allowing the turbine to yaw freely. The yaw drive was disabled about 5 seconds into the campaign, and the turbine was allowed to yaw freely for the rest of the 30-second duration. When the yaw drive is disabled, no torque is applied to the motor, and the inertia and yawing force of the nacelle and rotor overcomes the friction and inertia of the yaw gear and motor. The yaw releases were repeated five times at each condition. Four additional campaigns were collected to determine the turbine’s natural yaw error by releasing the brake at 0° yaw error. These file names use the E designation, followed by two digits for wind speed, followed by XXXX, followed by the repetition digit.
The primary goal of the basin model test program discussed herein is to properly scale and accurately capture physical data of the rigid body motions, accelerations and loads for different floating wind turbine platform technologies. The intended use for this data is for performing comparisons with predictions from various aero-hydro-servo-elastic floating wind turbine simulators for calibration and validation. Of particular interest is validating the floating offshore wind turbine simulation capabilities of NREL’s FAST open-source simulation tool. Once the validation process is complete, coupled simulators such as FAST can be used with a much greater degree of confidence in design processes for commercial development of floating offshore wind turbines. The test program subsequently described in this report was performed at MARIN (Maritime Research Institute Netherlands) in Wageningen, the Netherlands. The models considered consisted of the horizontal axis, NREL 5 MW Reference Wind Turbine (Jonkman et al., 2009) with a flexible tower affixed atop three distinct platforms: a tension leg platform (TLP), a spar-buoy modeled after the OC3 Hywind (Jonkman, 2010) and a semi-submersible. The three generic platform designs were intended to cover the spectrum of currently investigated concepts, each based on proven floating offshore structure technology. The models were tested under Froude scale wind and wave loads. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine which exhibits negligible swirl and low turbulence intensity in the flow field. Recorded data from the floating wind turbine models included rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions and accelerations at key locations on the nacelle, tower, and platform. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with irregular sea states and dynamic winds.
The goal of flight flutter testing is to detect possibly destructive modes of aircraft vibration which may arise during flight from interaction of aerodynamic forces with structural dynamic properties of the airframe. This is typically accomplished by exciting the airframe with a time varying force and monitoring the response of the aircraft throughout its flight envelope. The data generated must be analyzed and presented so that the frequency and time of occurrence of excited modes are clearly and unambiguously displayed. Processing and display in near real time is also desirable. Display of data in the time-frequency plane is a natural choice because it is a familiar and intuitive framework. The Matching Pursuit algorithm provides a time-frequency analysis with good adaptability to signal structure and good signal representation in the time-frequency plane. Improvements in efficiency are needed before the algorithm can be used in real time, however.
The objectives of the hot section technology (HOST) burner liner cyclic rig test program are basically threefold: (1) to assist in developing predictive tools needed to improve design analyses and procedures for the efficient and accurate prediction of burner liner structural response; (2) to calibrate, evaluate and validate these predictive tools by comparing the predicted results with the experimental data generated in the tests; and (3) to evaluate existing as well as advanced temperature and strain measurement instrumentation, both contact and noncontact, in a simulated engine cycle environment. The data generated will include measurements of the thermal environment (metal surface temperatures) as well as structural (strain) and life (fatigue) responses of simulated burner liners and specimens under controlled boundary and operating conditions. These data will be used to calibrate, compare and validate analytical theories, methodologies and design procedures, as well as improvements in them, for predicting liner temperatures, stress-strain responses and cycles to failure. Comparison of predicted results with experimental data will be used to show where the predictive theories, etc. need improvements. In addition, as the predictive tools, as well as the tests, test methods, and data acquisition and reduction techniques, are developed and validated, a proven, integrated analysis/experiment method will be developed to determine the cyclic life of a simulated burner liner.
Sequence 7: Shroud Operating (P) This test sequence used a downwind, rigid turbine with a 3.4° cone angle. The wind speed ranged from 5 m/s to 25 m/s. Turntable angles from 0° to 30° were achieved, but the yaw error angle was maintained at 0° by adjusting the nacelle yaw. The blade tip pitch was 3°. The rotor rotated at 72 RPM. Blade and probe pressure measurements were collected. The teeter dampers were replaced with rigid links, and these two channels were flagged as not applicable by setting the measured values in the data file to –99999.99 Nm. The teeter link load cell was pre-tensioned to 40,000 N. An airfoil-shaped aluminum shroud was placed on the tower below the 34% span five-hole probe. It extended below the 91% span five-hole probe. The turntable angle was adjusted to position the shroud at various angles relative to the flow, but the turbine yaw error angle was maintained at 0°. Two additional points were collected where the turntable angle was 0°, and the turbine yaw angle was 20° (71000200) or -20° (710M0200).
Sequence W: Extended Blade (F) This test sequence used an upwind, rigid turbine with a 0° cone angle. The wind speed ranged from 5 m/s to 21 m/s, and the yaw angle was held at 0°. The blade pitch angle was 3°. The rotor rotated at 72 RPM. Blade pressure measurements were collected. The five-hole probes were removed and the plugs were installed. Plastic tape 0.03-mm thick was used to smooth the interface between the plugs and the blade. The teeter dampers were replaced with rigid links, and these two channels were flagged as not applicable by setting the measured values in the data file to –99999.99 Nm. The teeter link load cell was pretensioned to 40,000 N. During postprocessing, the probe channels were set to read –99999.99. The standard tip blocks were replaced with blade extensions that created a 5.532-m radius rotor as shown in Appendix A. The extension used the S809 airfoil throughout, and the linear taper of the blade continued along the extension. Note that the blade radius was not changed during post-processing so the pressure tap locations are at the same radial location, but the reference to 30% represents 30% of 5.029 m, not 5.532 m. Throughout this report, references to the blade span are made for the 5.029-m radius, not the 5.532-m radius.