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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 325 records · Page 18

Simulation Test Of Descent Advisor

Report describes piloted-simulation test of Descent Advisor (DA), subsystem of larger automation system being developed to assist human air-traffic controllers and pilots. Focuses on results of piloted simulation, in which airline crews executed controller-issued descent advisories along standard curved-path arrival routes. Crews able to achieve arrival-time precision of plus or minus 20 seconds at metering fix. Analysis of errors generated in turns resulted in further enhancements of algorithm to increase accuracies of its predicted trajectories. Evaluations by pilots indicate general support for DA concept and provide specific recommendations for improvement.

Davis, Thomas J.↗

Analysis of validation tests of the Langley pilot transonic cryogenic tunnel

A pilot transonic cryogenic pressure tunnel has recently been developed and proof tested at the NASA Langley Research Center. In addition to providing an attractive method for obtaining high Reynolds number results at moderate aerodynamic loadings and tunnel power, this unique tunnel allows the independent determination of the effects of Reynolds number, Mach number, and dynamic pressure (aeroelasticity) on the aerodynamic characteristics of the model under test. The proof of concept experimental and theoretical studies are briefly reviewed. Experimental results obtained on both two- and three-dimensional models have substantiated that cryogenic test conditions can be set accurately and that cryogenic gaseous nitrogen is a valid test medium.

Ray, E. J.↗

Evaluation of an envelope-limiting device using simulation and flight test of a remotely piloted research vehicle

The operating characteristics of a nonlinear envelope-limiting device were investigated at extreme flight conditions by using a real time digital aircraft spin simulation and flight tests of a scale model remotely piloted research vehicle. A digital mechanization of the F-15 control system, including the stall inhibiter, was used in the simulation and in the control system of the scale model. The operational characteristics of the stall inhibiter and the effects of the stall inhibiter on the spin susceptibility of the airplane were investigated.

Petersen, K. L.↗

A flight test evaluation of the pilot interface with a digital advanced avionics system

A flight study was conducted to study pilot workload and the pilot interface with high levels of avionics capability and automation. The study was done in the context of general aviation, single-pilot IFR operations and utilized an experimental, digital, integrated avionics system. Results indicate that such advanced systems can provide improved information to the pilot and increased functional capability. The results also indicate that additional research is needed to increase the knowledge base required to design the pilot interfaces with highly capable systems. A CRT-based moving map display format tested provided excellent navigational situational awareness but was inferior to an HSI for manual path tracking. The complexity of navigation data management, autopilot management, and maintaining awareness of system status contributed to pilot workload and errors. Suggested guidelines for the design of the pilot/avionics interface for advanced avionics systems are given.

Hinton, D. A.↗

Engineering-Scale Test of a Water-Lean Solvent for Post-Combustion Capture

EPRI, Pacific Northwest National Laboratory, RTI International, and their project collaborators developed an engineering-scale test of a new water-lean solvent, N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (EEMPA or 2-EEMPA) as a post-combustion CO 2 capture solvent for power plant applications. This test was conducted using the Pilot Solvent Test Unit at the National Carbon Capture Center. The primary objective of this test was to collect long-term data operating EEMPA with both coal- and natural gas-representative flue gases at the approximately 0.5 MW e -equivalent scale (5–10 metric tons CO 2 /day captured). This report details the activities preparing for that test, data collected during the test campaign, and analyses and interpretations of that data.

20 FOSSIL-FUELED POWER PLANTS↗

Exxon Mobil-NETL Testing of DAC Materials

This joint initiative is aimed at extending our understanding of real DAC testing conditions at the NETL DAC testbed facility. Of particular focus will be: • Small Scale testing of powdered and formulated materials (supplied by ExxonMobil) to evaluate various performance metrics under DAC process cycles • Pilot scale testing of formulated materials at larger scales ExxonMobil will work with NETL to shake down equipment, validate testing methods, and define best practices for data analysis. Three tasks are proposed: 1. Validation of multi-cycle test data on powdered and formulated materials to benchmark various performance metrics of these materials. 2. Steam regeneration of powdered samples at small scale to define baseline performance under commercially relevant conditions. 3. Pilot scale testing of larger formulated materials to test commercially relevant samples under actual process cycles.

36 MATERIALS SCIENCE↗

Initial results from flight testing a large, remotely piloted airplane model

The first four flights of a remotely piloted airplane model showed that a flight envelope can be expanded rapidly and that hazardous flight tests can be conducted safely with good results. The flights also showed that aerodynamic data can be obtained quickly and effectively over a wide range of flight conditions, clear and useful impressions of handling and controllability of configurations can be obtained, and present computer and electronic technology provide the capability to close flight control loops on the ground, thus providing a new method of design and flight test for advanced aircraft.

Holleman, E. C.↗

Pilot model expansion tunnel test flow properties obtained from velocity, pressure, and probe measurements

Velocity-profile, pitot-pressure, and supplemental probe measurements were made at the nozzle exist of an expansion tunnel (a modification to the Langley pilot model expansion tube) for a nozzle net condition of a nitrogen test sample with a velocity of 4.5 km/sec and a density 0.005 times the density of nitrogen at standard conditions, both with the nozzle initially immersed in a helium atmosphere and with the nozzle initially evacuated. The purpose of the report is to present the results of these measurements and some of the physical properties of the nitrogen test sample which can be inferred from the measured results. The main conclusions reached are that: the velocity profiles differ for two nozzle conditions; regions of the flow field can be found where the velocity is uniform to within 5 percent and constant for several hundred microseconds; the velocity of the nitrogen test sample is reduced due to passage through the nozzle; and the velocity profiles do not significantly reflect the large variations which occur in the inferred density profiles.

Friesen, W. J.↗

Lithium-doped solar cell pilot line fabrication and test programs

An investigation was conducted to determine the technology readiness of lithium-doped silicon solar cells with respect to use in space programs. A pilot line fabrication program was established, in which the pilot line cells were evaluated after being exposed to environments ordinarily imposed on nonlithium-doped silicon solar cells. Results indicate that further process improvements are required, particularly with respect to the P/N junction diffusion and the electrical contacting technique (including solder coating). It is concluded that lithium-doped cells can be fabricated to exhibit (1) high efficiencies, (2) uniform cell-to-cell recovery characteristics after exposure to 1-MeV electrons; and (3) good stability in most environments investigated (the only exception being the thermal shock environment).

Berman, P. A.↗

Vitrification of Inactive Incineration Ash in a Full Industrial Scale In Can Melter - 20502

In the framework of the H2020 THERAMIN project funded by the European Commission, CEA performed a pilot-scale trial consisting of the vitrification of inactive ash (Al, Ca, Si, Zn, Bi, K, Mg, etc.) using the In- Can Melter technology. These ashes were coming from incineration of simulated technological wastes such as cotton, latex, neoprene, polyethylene. The borosilicate glass feasibility was first evaluated at a laboratory scale (10-100 g of glass). The volatile behavior of fly ash was controlled by pelletizing to avoid pipes clogging when performing the pilot scale test. A 10 wt.% inorganic binder was added to obtain cohesive pellets. The glass frit composition was selected and its ratio was fixed at 50 wt.%. After this step, a bench test (1 kg of glass) was done to verify the absence of container corrosion. Finally, it was followed by a pilot scale test (50 kg of glass) with 75,000 ash pellets used. The same glass microstructure and chemical composition were observed at each scale. Typical crystals of apatites (Ca, P), zincochromites (Zn, Cr, Al) and bismuth alloys (Bi, Sb) dispersed into a borosilicate glass matrix were observed. The chemical durability of the wasteform was measured during 28 days in a 90 deg. C water. Although there were durable crystalline phases, the hydrolysis rate of the vitreous part is relatively high because of the B and Na contents. However, leach rate profiles suggest that an alteration layer will form, leading to an alteration rate decrease. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Structural dynamics research in a full-scale transport aircraft crash test

A remotely piloted air-to-ground crash test of a full-scale transport aircraft was conducted for the first time for two purposes: (1) to demonstrate performance of an antimisting fuel additive in suppressing fire in a crash environment, and (2) to obtain structural dynamics data under crash conditions for comparison with analytical predictions. The test, called the Controlled Impact Demonstration (CID), was sponsored by FAA and NASA with cooperation of industry, the Department of Defense, and the British and French governments. The test aircraft was a Boeing 720 jet transport. The aircraft impacted a dry lakebed at Edwards Air Force Base, CA. The purpose of this paper is to discuss the structural aspects of the CID. The fuselage section tests and the CID itself are described. Structural response data from these tests are presented and discussed. Nonlinear analytical modeling efforts are described, and comparisons between analytical results and experimental results are presented.

Mccomb, H. G., Jr.↗

Piloted Parameter Identification Flight Test Maneuvers for Closed Loop Modeling of the F-18 High Alpha Research Vehicle (HARV)

Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for closed loop parameter identification purposes, specifically for longitudinal and lateral linear model parameter estimation at 5, 20, 30, 45, and 60 degrees angle of attack, using the NASA 1A control law. Each maneuver is to be realized by the pilot applying square wave inputs to specific pilot station controls. Maneuver descriptions and complete specifications of the time/amplitude points defining each input are included, along with plots of the input time histories.

Morelli, Eugene A.↗

Real-Time Onboard Global Nonlinear Aerodynamic Modeling from Flight Data

Flight test and modeling techniques were developed to accurately identify global nonlinear aerodynamic models onboard an aircraft. The techniques were developed and demonstrated during piloted flight testing of an Aermacchi MB-326M Impala jet aircraft. Advanced piloting techniques and nonlinear modeling techniques based on fuzzy logic and multivariate orthogonal function methods were implemented with efficient onboard calculations and flight operations to achieve real-time maneuver monitoring and analysis, and near-real-time global nonlinear aerodynamic modeling and prediction validation testing in flight. Results demonstrated that global nonlinear aerodynamic models for a large portion of the flight envelope were identified rapidly and accurately using piloted flight test maneuvers during a single flight, with the final identified and validated models available before the aircraft landed.

Brandon, Jay M.↗

Pilot In-Trail Procedure Validation Simulation Study

A Human-In-The-Loop experiment was conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) to investigate the viability of the In-Trail Procedure (ITP) concept from a flight crew perspective, by placing participating airline pilots in a simulated oceanic flight environment. The test subject pilots used new onboard avionics equipment that provided improved information about nearby traffic and enabled them, when specific criteria were met, to request an ITP flight level change referencing one or two nearby aircraft that might otherwise block the flight level change. The subject pilots subjective assessments of ITP validity and acceptability were measured via questionnaires and discussions, and their objective performance in appropriately selecting, requesting, and performing ITP flight level changes was evaluated for each simulated flight scenario. Objective performance and subjective workload assessment data from the experiment s test conditions were analyzed for statistical and operational significance and are reported in the paper. Based on these results, suggestions are made to further improve the ITP.

Bussink, Frank J. L.↗

Flight test experience with pilot-induced-oscillation suppressor filters

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Shafer, M. F.↗