Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Flight Test”

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.

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

At least 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Comparison of ground and flight test results using a modified F106B aircraft

A F106 aircraft was modified by installing two additional underwing nacelles housing afterburning J85 engines to study exhaust nozzles in flight at Mach numbers up to 1.3. Installation effects were determined for several nozzles by comparing flight and wind-tunnel data. The effect is to decrease boattail drag and delay its drag rise Mach number to about 0.98. A study of Reynolds number effects, carried out at subsonic speeds with afterburning turbofan engines showed boattail drag to be sensitive to Reynolds number. In flight, drag was highest at the lowest Reynolds number, and decreased as the Re number was increased. Static and flyover noise measurements showed that, except for special cases, noise levels at takeoff (M = 0.4) were higher than predicted from static data.

Wilcox, F. A.↗
NASA NTRS2000

Design and Flight Testing of an Inflatable Sunshield for the NGST

The Next Generation Space Telescope (NGST) mission is scheduled to launch in 2007 and be stationed at L2 for a mission life of ten years. The large aperture mirror and optical detectors aboard NGST require shielding from the constant solar energy seen at this orbit. The government reference NGST design, called the Yardstick, baselined a sunshield using an inflation deployment system. During the formulation phase, NGST is spending approximately 25% of the overall budget to foster the development of new technology. The goal is to develop and demonstrate enabling or enhancing technology and provide innovative solutions for the design of the NGST observatory. Inflatable technology falls in the category of enhancing technology due to its advantages in weight, stowed volume and cost. The Inflatable Sunshield in Space (ISIS) flight experiment will provide a realistic space flight demonstration of an inflatable sunshield. The supporting technology development program will provide an information base for the design, manufacture, assembly and testing of large thin membranes and inflatable structural elements for space structures. The ISIS experiment will demonstrate the feasibility of using inflatable technology to passively cool optical systems for NGST and provide correlation between analytical predictions and on orbit results. The experiment will be performed on a Hitchhiker/Space Shuttle mission in late 2001. The ISIS mission is an effort to address several major technical challenges of the NGST inflatable sunshield, namely controlled inflation deployment, plenarity and separation of large stretched membranes, space rigidization of inflatable booms, and dynamic modeling and simulation. This paper will describe the design of the flight experiment and the testing to be performed on-orbit.

Adams, Michael L.↗
NASA NTRS1992

Program overview: 1991 flight test objectives

The topics are presented in viewgraph form and include the following: the Joint NASA/FAA Airborne Wind Shear Detection and Avoidance Program; the windshear problem; NASA/FAA Wind Shear Program objectives; program elements; Wind Shear Program roadmap; airborne wind shear sensors; 1991 wind shear flight experiments; operative wind shear detection systems; research aircraft sensor installations; and 1991 test results.

Bowles, Roland L.↗
NASA NTRS1986

Design considerations for flight test of a fault inferring nonlinear detection system algorithm for avionics sensors

The modifications to the design of a fault inferring nonlinear detection system (FINDS) algorithm to accommodate flight computer constraints and the resulting impact on the algorithm performance are summarized. An overview of the flight data-driven FINDS algorithm is presented. This is followed by a brief analysis of the effects of modifications to the algorithm on program size and execution speed. Significant improvements in estimation performance for the aircraft states and normal operating sensor biases, which have resulted from improved noise design parameters and a new steady-state wind model, are documented. The aircraft state and sensor bias estimation performances of the algorithm's extended Kalman filter are presented as a function of update frequency of the piecewise constant filter gains. The results of a new detection system strategy and failure detection performance, as a function of gain update frequency, are also presented.

Caglayan, A. K.↗
NASA NTRS1999

F-16XL and F-18 High Speed Acoustic Flight Test Databases

This report presents the recorded acoustic data and the computed narrow-band and 1/3-octave band spectra produced by F-18 and F-16XL aircraft in subsonic flight over an acoustic array. Both broadband-shock noise and turbulent mixing noise are observed in the spectra. Radar and c-band tracking systems provided the aircraft position which enabled directivity and smear angles from the aircraft to each microphone to be computed. These angles are based on source emission time and thus give some idea about the directivity of the radiated sound field due to jet noise. A follow-on static test was also conducted where acoustic and engine data were obtained. The acoustic data described in the report has application to community noise analysis, noise source characterization and validation of prediction models. A detailed description of the signal processing procedures is provided. Follow-on static tests of each aircraft were also conducted for which engine data and far-field acoustic data are presented.

Kelly, J. J.↗
NASA NTRS2007

Ares I-X Flight Test--The Future Begins Here

In less than two years, the National Aeronautics and Space Administration (NASA) will launch the Ares I-X mission. This will be the first flight of the Ares I crew launch vehicle, which, together with the Ares V cargo launch vehicle, will eventually send humans to the Moon, Mars, and beyond. As the countdown to this first Ares mission continues, personnel from across the Ares I-X Mission Management Office (MMO) are finalizing designs and fabricating vehicle hardware for a 2009 launch. This paper will discuss the hardware and programmatic progress of the Ares I-X mission.

Davis, Stephan R.↗
NASA NTRS1988

The flight test of a grazing incidence relay optics telescope for solar X-ray astronomy utilizing a thinned, back-illuminated CCD detector

The new AS&E Ultrahigh Resolution Soft X-ray Solar Research Rocket Payload has been successfully flown twice on Black Brant IX Sounding Rockets from White Sands Missile Range. These flights, conducted on 15 August 1987 and 11 December 1987, provided the first test of the new payload which consists of 3.8X magnifying hyperboloid-hyperboloid grazing incidence relay optic used in conjunction with an existing Wolter-I primary mirror. An RCA SID 500 series CCD detector was utilized in a thinned, back-illuminated configuration for recording the images. The 5.4 m effective focal length of the compound optics system resulted in a plate scale of 1 arc second per pixel which is comparable to the inherent resolution of the primary mirror. These flights represent the first use in X-ray astronomy of either of these two new technologies. These observations are presented with comparison to laboratory measurements and theoretical expectations of the instrument performance.

Moses, J. Daniel↗
NASA NTRS1969

Flight Tests Results from Supersonic Deployment of an 18-Foot Diameter (5.49 meter) Towed Ballute Decelerator

A ram-air-inflated, towed ballute decelerator having a maximum frontal diameter of 18 feet (5.49 meters) was deployed during free flight at a Mach number of 3.15 and a dynamic pressure of 38.5 lb/ft(exp 2) (1843.4 newtons/m(exp 2)). Deployment and extraction of the test ballute were normal but inflation stopped about 1 second after mortar firing and produced an average plateau drag force of 1500 pounds (6.7 kN) for about 1 second. Approximately 30 percent of expected total frontal area was obtained.

TESTS↗
NASA NTRS1992

Comparison ofdvanced turboprop interior noise control ground and flight test data

Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight sts with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

Simpson, Myles A.↗
NASA NTRS1992

Flight-test guidance for airbreathing hypersonic vehicles

A guidance solution for aerospace planes is given based on a family of energy-heading extremal solutions that can be used for feedback implementations. Test conditions are developed as steady-cruise solutions by means of energy-heading extremal solutions to a time/fuel-range flight-optimization problem. Feedback charts are derived that give control as a function of energy and heading-to-go, and the reduced-order model is compared to numerically optimized point-mass solutions for flight optimization. The energy-heading model is shown to provide feedback-control charts that yield fuel-efficient turn/acceleration maneuvers with significant weight-change as compared to the point-mass solutions. Such variables as Mach number, dynamic pressure, and lift are found to influence the solutions significantly.

Cliff, Eugene M.↗
NASA NTRS1930

Flight Tests on U.S.S. Los Angeles. Part I : Full Scale Pressure Distribution Investigation

The primary purpose of this investigation was to obtain simultaneous data on the loads and stress experience in flight by the U. S. S. Los Angeles which could be used in rigid airship structure design. A secondary object of the investigation was to determine the turning and drag characteristics of the airship. The aerodynamic loading was obtained by measuring the pressure at 95 locations on the tail surfaces, 54 on the hull, and 5 on the passenger car. These measurements were made during a series of maneuvers consisting of turns and reversals in smooth air and during a cruise in rough air which was just short of squall proportions. The results of the pressure measurements on the hull indicate that the forces on the forebody of an airship are relatively small. The tail surface measurements show conclusively that the forces caused by gusts are much greater than those caused by horizontal maneuvers. In this investigation the tail surface loadings caused by gusts closely approached the designed loads of the tail structure. The turning and drag characteristics will be reported in separate reports.

De France, S J↗
NASA NTRS1983

Flight-test results using nonlinear control with the F-8C digital fly-by-wire aircraft

The design and operation of the cooperative advanced digital research experiment (CADRE) to develop nonlinear pitch flight control algorithms is described, and the results of an in-flight evaluation using the F-8C digital fly-by-wire (DFBW) research aircraft are presented. The CADRE controller is described, including the initial filter, linear command prefilter, nonlinear command prefilter, and gain scheduling. The variable-integral control-to-optimize response of the controller is considered, and CADRE parameter combinations are addressed. The remotely-augmented-vehicle interface used in the DFBW aircraft experiment is discussed. The distanct-tracking and close-formation tracking evaluation tasks for the aircraft are described along with evaluation configurations, and the test results are presented and discussed. The latter indicate that a nonlinear adaptive controller is a feasible control system technique for the fighter tracking task.

Larson, R. R.↗
NASA NTRS1983

The ocean color experiment (OCE) on the second orbital flight test of the Space Shuttle (OSTA-1)

The Ocean Color Experiment was one of the six remote-sensing experiments which for the first time were launched and successfully operated on board of the second flight of the Space Shuttle during November 1981. The experiment consists of a multispectral image scanner dedicated to the measurement of water color and its interpretation in terms of major water constituents and circulation patterns. The objectives of the experiment, the test site selection, and associated activities are described. The actual mission and results of an initial data analysis is discussed.

Van Der Piepen, H.↗
NASA NTRS1973

Development and flight test of a digital fly-by-wire F8.

The objective of the F-8 digital fly-by-wire program is to establish a technology base for the implementation of advanced flight control systems. The central element is the Apollo Lunar Guidance Computer (LGC). This versatile computer ran over 2000 hours in support of fly-by-wire without a failure. Difficulties encountered in the first flights were corrected rapidly and simply by changes in the erasable software memory. Control-configured vehicles offer significant weight-saving possibilities.

Peterson, B. A.↗
NASA NTRS1974

Omega flight-test data reduction sequence

Computer programs for Omega data conversion, summary, and preparation for distribution are presented. Program logic and sample data formats are included, along with operational instructions for each program. Flight data (or data collected in flight format in the laboratory) is provided by the Ohio University Omega receiver base in the form of 6-bit binary words representing the phase of an Omega station with respect to the receiver's local clock. All eight Omega stations are measured in each 10-second Omega time frame. In addition, an event-marker bit and a time-slot D synchronizing bit are recorded. Program FDCON is used to remove data from the flight recorder tape and place it on data-processing cards for later use. Program FDSUM provides for computer plotting of selected LOP's, for single-station phase plots, and for printout of basic signal statistics for each Omega channel. Mean phase and standard deviation are printed, along with data from which a phase distribution can be plotted for each Omega station. Program DACOP simply copies the Omega data deck a controlled number of times, for distribution to users.

Lilley, R. W.↗
NASA NTRS1986

Design considerations for flight test of a fault inferring nonlinear detection system algorithm for avionics sensors

This paper summarizes the modifications made to the design of a fault inferring nonlinear detection system (FINDS) algorithm to accommodate flight computer constraints and the resulting impact on the algorithm performance. An overview of the flight data-driven FINDS algorithm is presented. This is followed by a brief analysis of the effects of modifications to the algorithm on program size and execution speed. Significant improvements in estimation performance for the aircraft states and normal operating sensor biases, which have resulted from improved noise design parameters and a new steady-state wind model, are documented. The aircraft state and sensor bias estimation performances of the algorithm's extended Kalman filter are presented as a function of update frequency of the piecewise constant filter gains. The results of a new detection system strategy and failure detection performance, as a function of an update frequency, are also presented.

Caglayan, A. K.↗