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  1. MECHANICAL- AND THERMAL-BUCKLING BEHAVIOR OF RECTANGULAR PLATES WITH DIFFERENT CENTRAL CUTOUTS , Technical Memorandum
    Authors: William L. Ko
    Report Number: NASA-TM-1998-206542
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Mechanical- and thermal-buckling analyses were performed on rectangular plates with central cutouts. The cutouts were either circular holes or square holes. The finite-element structural analysis method was used to study the effects of plate-support conditions, plate aspect ratio, hole geometry, and hole size on the mechanical-and thermal-buckling strengths of the perforated plates. By increasing the hole size, thermal-buckling strengths of the plates could be enhanced. The compressive-buckling strengths of the plates could also be increased considerably only under certain boundary conditions and aspect ratios. The plate-buckling mode can be symmetrical or antisymmetrical, depending on the plate boundary conditions, aspect ratio, and the hole size. For the same cutout areas (i.e., same plate weight density), the buckling strengths of the same-sized plates with square holes generally surpass those of the plates with circular holes over the range of hole sizes. The results and illustrations provide vital information for the efficient design of aerospace structural panels.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 39
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          Postscript (1,201 KBytes)
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    Report Date: March 1998
    No. Pages: 47
    Funding Organization: WU 522 32 34
    Keywords:      Buckling mode shapes; Mechanical buckling; Plates with circular holes; Plateswith square holes; Thermal buckling


  2. ROBUST FLUTTER MARGIN ANALYSIS THAT INCORPORATES FLIGHT DATA , Technical Paper
    Authors: Rick Lind and Martin J. Brenner
    Report Number: NASA-TP-1998-206543
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An approach for computing worst-case flutter margins has been formulated in a robust stability framework. Uncertainty operators are included with a linear model to describe modeling errors and flight variations. The structured singular value, mu, computes a stability margin that directly accounts for these uncertainties. This approach introduces a new method of computing flutter margins and an associated new parameter for describing these margins. The mu margins are robust margins that indicate worst-case stability estimates with respect to the defined uncertainty. Worst-case flutter margins are computed for the F/A-18 Systems Research Aircraft using uncertainty sets generated by flight data analysis. The robust margins demonstrate flight conditions for flutter may lie closer to the flight envelope than previously estimated by p-k analysis.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: March 1998
    No. Pages: 104
    Funding Organization: WU 529 31 14
    Keywords:      Aeroelasticity; Flight data analysis; Flutter; Robust stability; Structural dynamics;Structured singular value
    Notes: Rick Lind is a National Research Council research associate.


  3. DESIGN AND CALIBRATION OF THE X-33 FLUSH AIRDATA SENSING (FADS) SYSTEM , Technical Memorandum
    Authors: Stephen A. Whitmore, Brent R. Cobleigh and Edward A. Haering
    Report Number: NASA-TM-206540
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper presents the design of the X-33 Flush Airdata Sensing (FADS) system. The X-33 FADS uses a matrix of pressure orifices on the vehicle nose to estimate airdata parameters. The system is designed with dual-redundant measurement hardware, which produces two independent measurement paths. Airdata parameters that correspond to the measurement path with the minimum fit error are selected as the output values. This method enables a single sensor failure to occur with minimal degrading of the system performance. The paper shows the X-33 FADS architecture, derives the estimating algorithms, and demonstrates a mathematical analysis of the FADS system stability. Preliminary aerodynamic calibrations are also presented here. The calibration parameters, the position error coefficient (epsilon), and flow correction terms for the angle of attack (delta alpha), and angle of sideslip (delta beta) are derived from wind tunnel data. Statistical accuracy of the calibration is evaluated by comparing the wind tunnel reference conditions to the airdata parameters estimated. This comparison is accomplished by applying the calibrated FADS algorithm to the sensed wind tunnel pressures. When the resulting accuracy estimates are compared to accuracy requirements for the X-33 airdata, the FADS system meets these requirements.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 06
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    Report Date: January 1998
    No. Pages: 35
    Funding Organization: 242-33-02-00-23-00-TA3
    Keywords:      FADS Calibration; Flush airdata sensing (FADS); X-33; Redundancy Management; Reusable Launch Vehicle (RLV)
    Notes: Presented at the AIAA Aerospace Sciences Meeting and Exhibit, January 12-15, 1998, Reno, Nevada. AIAA-98-0201


  4. ATMOSPHERIC CONSIDERATIONS FOR UNINHABITED AERIAL VEHICLE (UAV) FLIGHT TEST PLANNING , Technical Memorandum
    Authors: Edward H. Teets, Jr. , Casey J. Donohue , Ken Underwood and Jeffrey E. Bauer
    Report Number: NASA-TM-1998-206541
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Atmospheric considerations are a key element in support of uninhabited aerial vehicle (UAV) flight testing. The local atmospheric environment (wind speed and direction, wind shear, temperature, precipitation, and turbulence) must be characterized and understood. The primary objective is to ensure safety of the vehicle, test range, and ground assets. The generalized atmospheric behavior for any potential flight operations site is best described by combining the local seasonal climatology, daily upper atmospheric wind and temperature profiles, and hourly surface and low-level wind observations. This paper describes a continuous forecast update process based on monitoring atmospheric turbulence with surface and low-level wind for the support of UAV flights. Updates ensure the most current available data needed for mission planning. Each mission plan is developed so as not to exceed operation limits because of weather conditions. This paper also discusses climatology, weather forecasts, and day-of-flight weather monitoring for planning of uninhabited aerial vehicle missions.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 47
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    Report Date: January 1998
    No. Pages: 17
    Funding Organization: WU 242-33-02-00-23-00-T14
    Keywords:      Atmosphere; Climatology; Flight test planning; Uninhabited aerial vehicle (UAV);
    Notes: Presented as AIAA 98-0748 at the AIAA 36th Aerospace Sciences Meeting & Exhibit, Reno, Nevada, January 12-15, 1998. Edward Teets, Casey Donohue, AS&M Inc., Edwards, CA; Ken Underwood, AeroVironment, Inc., Monrovia, CA; Jeffrey Bauer, NASA Dryden, CA


  5. DEVELOPMENT OF THE X-33 AERODYNAMIC UNCERTAINTY MODEL , Technical Paper
    Authors: Brent R. Cobleigh
    Report Number: NASA-TP-206544
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An aerodynamic uncertainty model for the X-33 single-stage-to-orbit demonstrator aircraft has been developed at NASA Dryden Flight Research Center. The model is based on comparisons of historical flight test estimates to preflight wind-tunnel and analysis code predictions of vehicle aerodynamics documented during six lifting-body aircraft and the Space Shuttle Orbiter flight programs. The lifting-body and Orbiter data were used to define an appropriate uncertainty magnitude in the subsonic and supersonic flight regions, and the Orbiter data were used to extend the database to hypersonic Mach numbers. The uncertainty data consist of increments or percentage variations in the important aerodynamic coefficients and derivatives as a function of Mach number along a nominal trajectory. The uncertainty models will be used to perform linear analysis of the X-33 flight control system and Monte Carlo mission simulation studies. Because the X-33 aerodynamic uncertainty model was developed exclusively using historical data rather than X-33 specific characteristics, the model may be useful for other lifting-body studies.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 02
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    Report Date: April 1998
    No. Pages: 38
    Funding Organization: WU 242 33 02 00 23 00 TA2
    Keywords:      Aerodynamic uncertainty; Lifting-body aircraft; Monte Carlo simulation; Reusable


  6. WAVELET FILTERING TO REDUCE CONSERVATISM IN AEROSERVOELASTIC ROBUST STABILITY MARGINS , Technical Memorandum
    Authors: Marty Brenner and Rick Lind
    Report Number: NASA-TM-206545
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Wavelet analysis for filtering and system identification was used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins was reduced with parametric and nonparametric time-frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data was used to reduce the effects of external desirableness and unmodeled dynamics. Parametric estimates of modal stability were also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. F-18 High Alpha Research Vehicle aeroservoelastic flight test data demonstrated improved robust stability prediction by extension of the stability boundary beyond the flight regime.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: March 1998
    No. Pages: 16
    Funding Organization: WU 529 50 04
    Keywords:      Aeroservoelasticity; Modal estimation; Robust stability; Uncertainty modeling; Wavelet analysis
    Notes: Rick Lind is a National Research Council research associate. AIAA 98-1896 - presented at the AIAA Structures, Structural Dynamics and Materials Conference, Long Beach, California, April 20-23, 1998.


  7. CORRELATION FILTERING OF MODAL DYNAMICS USING THE LAPLACE WAVELET , Conference Paper
    Authors: Lawrence C. Freudinger, Rick Lind and Martin J. Brenner
    Report Number: H-2223
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Wavelet analysis allows processing of transient response data commonly encountered in vibration health monitoring tasks such as aircraft flutter testing. The Laplace wavelet is formulated as an impulse response of a single mode system to be similar to data features commonly encountered in these health monitoring tasks. A correlation filtering approach is introduced using the Laplace wavelet to decompose a signal into impulse responses of single mode subsystems. Applications using responses from flutter testing of aeroelastic systems demonstrate modal parameters and stability estimates can be estimated by correlation filtering free decay data with a set of Laplace wavelets.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: February 1998
    No. Pages: 10
    Funding Organization: 505-63-50
    Keywords:      Aeroelasticity; Correlation filtering; Health monitoring; Parameter estimation; Wavelet
    Notes: Presented at the 16th International Modal Analysis Conference, Santa Barbara, California, February 2-5, 1998.


  8. USING ENGINE THRUST FOR EMERGENCY FLIGHT CONTROL: MD-11 AND B-747 RESULTS , Technical Memorandum
    Authors: Frank W. Burcham, Jr. , Trindel A. Maine , John J. Burken and John Bull
    Report Number: NASA-TM-1998-206552
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: With modern digital control systems, using engine thrust for emergency flight control to supplement or replace failed aircraft normal flight controls has become a practical consideration. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control. An F-15 and an MD-11 airplane have been landed without using any flight control surfaces. Preliminary studies have also been conducted that show that engines on only one wing can provide some flight control capability if the lateral center of gravity can be shifted toward the side of the airplane that has the operating engine(s). Simulator tests of several airplanes with no flight control surfaces operating and all engines out on the left wing have all shown positive control capability within the available range of lateral center-of- gravity offset. Propulsion-controlled aircraft systems that can operate without modifications to engine control systems, thus allowing PCA technology to be installed on less capable airplanes or at low cost, are also desirable. Further studies have examined simplified "PCA Lite" and "PCA Ultralite" concepts in which thrust control is provided by existing systems such as autothrottles or a combination of existing systems and manual pilot control.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 03
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    Report Date: May 1998
    No. Pages: 31
    Funding Organization: WU 522-15-34-00-39-00-IDA
    Keywords:      B-747; Emergency control; MD-11; Propulsion control; Throttle-only-control
    Notes: Paper presented at the Aviation Safety Issues session of the American Society of Mechanical Engineers 43rd Gas Turbine and Aeroengine Technical Congress, Exposition, and Users Symposium, June 25, 1998, Stockholm, Sweden.


  9. RECENT FLIGHT TEST EXPERIENCE WITH UNINHABITED AERIAL VEHICLES AT THE NASA DRYDEN FLIGHT RESEACH CENTER , Technical Memorandum
    Authors: John H. Del Frate and Gary B. Cosentino
    Report Number: NASA-TM-1998-206546
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The NASA Dryden Flight Research Center has had substantial involvement with uninhabited aerial vehicles (UAVs) in the past. These vehicles include the Highly Maneuverable Aircraft Technology (HiMAT) aircraft and a new breed of UAVs, such as the X-36 and the Pathfinder. This article describes lessons learned with the current UAVs which may help others in any stage of UAV design or flight testing. Topics discussed include airspace factors, weather factors, frequency availability, range safety, human factors and crew station design, hardware and software design redundancy, ground testing, simulator use, flight testing procedures, crew training, and environmental testing.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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          Postscript (206 KBytes)
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    Report Date: April 1998
    No. Pages: 14
    Funding Organization: WU 529-10-04-M1-00
    Notes: To be published in The ITEA Journal of Test and Evaluation. 29-700S-000


  10. WEB-BASED INSTRUCTION AND LEARNING: ANALYSIS AND NEEDS ASSESSMENT , Technical Paper
    Authors: Barbara Grabowski, Marianne McCarthy and Tiffany Koszalka
    Report Number: NASA-TP-1998-206547
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An analysis and needs assessment was conducted to identify kindergarten through grade 14 (K14) customer needs with regard to using the World Wide Web (WWW) for instruction and to identify obstacles K14 teachers face in utilizing NASA Learning Technologies products in the classroom. The needs assessment was conducted as part of the Dryden Learning Technologies Project which is a collaboration between Dryden Flight Research Center (DFRC), Edwards, California and The Pennsylvania State University (PSU), University Park, Pennsylvania. The overall project is a multiyear effort to conduct research in the development of teacher training and tools for Web-based science, mathematics and technology instruction and learning. The project team conducting the research consisted of graduate students at PSU under the supervision of Dr. Barbara Grabowski, Associate Professor, PSU, and Dr. Marianne McCarthy, Learning Technologies Project Manager at DFRC. Jeff Ehmen of the Marshall Space Flight Center Spacelink program, Dr. Marchelle Canright of the Langley Research Center Office of Education and Lee Duke, Chief of Public Affairs, Commercialization, and Education at DFRC also contributed to the research effort. The areas investigated included administrative infrastructure, technology infrastructure, teacher factors, school curriculum, existing Web-based NASA materials, best practices using the WWW in the classroom, teacher tutorials and teaching and learning philosophy.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 81
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    Report Date: May 1998
    No. Pages: 75
    Funding Organization: WU 332-41-00-M1-00-TT-07
    Keywords:      Education; Learning technology; Pedagogy; Teacher tutorials; World wide web
    Notes: Presented at INET 1998 Internet Summit, Technology and Learnining Tract, Geneva, Switzerland, July 1998. Barbara Grabowski and Tiffany Koszalka, PSU, Grant NAG 4-113; Marianne McCarthy, AS&M, Inc., Contract 4-50066. E.L. Duke, NASA Technical Monitor.


  11. ANOMALOUS BUCKLING CHARACTERISTICS OF LAMINATED METAL-MATRIX COMPOSITE PLATES WITH CENTRAL SQUARE HOLES , Technical Paper
    Authors: William L. Ko
    Report Number: NASA-TP-1998-206559
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Compressive buckling analysis was performed on metal-matrix composite (MMC) plates with central square holes. The MMC plates have varying aspect ratios and hole sizes and are supported under different boundary conditions. The finite- element structural analysis method was used to study the effects of plate boundary conditions, plate aspect ratio, hole size, and the composite stacking sequence on the compressive buckling strengths of the perforated MMC plates. Studies show that by increasing the hole sizes, compressive buckling strengths of the perforated MMC plates could be considerably increased under certain boundary conditions and aspect ratios ('anomalous' buckling behavior); and that the plate buckling mode could be symmetrical or antisymmetrical, depending on the plate boundary conditions, aspect ratio, and the hole size. For same-sized plates with same-sized holes, the compressive buckling strengths of the perforated MMC plates with [90/0/ 0/90]2 lamination could be as much as 10 percent higher or lower than those of the [45/-45/-45/45]2 laminations, depending on the plate boundary conditions, plate aspect ratios, and the hole size. Clamping the plate edges induces far stronger "anomalous" buckling behavior (enhancing compressive buckling strengths at increasing hole sizes) of the perforated MMC plates than simply supporting the plate edges.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 39
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          Postscript (571 KBytes)
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    Report Date: July 1998
    No. Pages: 26
    Funding Organization: WU 522 32 34 00 RS 00 000 01


  12. RECENT FLIGHT TEST RESULTS OF THE JOINT CIAM-NASA MACH 6.5 SCRAMJET FLIGHT PROGRAM , Technical Memorandum
    Authors: Alexander S. Roudakov , Vyacheslav L. Semenov and John W. Hicks
    Report Number: NASA-TM-1998-206548
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Under a contract with NASA, a joint Central Institute of Aviation Motors (CIAM) and NASA team recently conducted the fourth flight test of a dual-mode scramjet aboard the CIAM Hypersonic Flying Laboratory, "Kholod." With an aim test Mach 6.5 objective, the successful launch was conducted at the Sary Shagan test range in central Kazakstan on February 12, 1998. Ground-launch, rocket boosted by a modified Russian SA5 missile, the redesigned scramjet was accelerated to a new maximum velocity greater than Mach 6.4. This launch allowed for the measurement of the fully supersonic combustion mode under actual flight conditions. The primary program objective was the flight-to-ground correlation of measured data with preflight analysis and wind-tunnel tests in Russia and potentially in the United States. This paper describes the development and objectives of the program as well as the technical details of the scramjet and SA5 redesign to achieve the Mach 6.5 aim test condition. An overview of the launch operation is also given. Finally, preliminary flight test results are presented and discussed.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 15
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    Report Date: April 1998
    No. Pages: 15
    Funding Organization: WU 242-33-02-00-53-00-RLV
    Keywords:      Flight test; Hypersonics technology; SA5 missile booster; Scramjet; Supersonic
    Notes: Presented at AIAA 8th International Spaceplanes and Hypersonic Systems and Technology Conference, April 2730, 1998, Norfolk, Virginia. Roudakov and Semenov, Central Institute of Aviation Motors, Moscow, Russia; Hicks, NASA Dryden, Edwards, CA


  13. OPERATIONAL CONCEPTS FOR UNINHABITED TACTICAL AIRCRAFT , Technical Memorandum
    Authors: Dwain A. Deets and Dana Purifoy
    Report Number: NASA-TM-1998-206549
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: This paper describes experiences with five remotely piloted flight research vehicle projects in the developmental flight test phase. These projects include the Pathfinder, Perseus B, Altus, and X-36 aircraft and the Highly Maneuverable Aircraft Technology (HiMAT). Each of these flight projects was flown at the NASA Dryden Flight Research Center. With the exception of the HiMAT, these projects are a part of the Flight Research Base Research and Technology (R&T) Program of the NASA Aeronautics and Space Transportation Technology Enterprise. Particularly with respect to operational interfaces between the ground-based pilot or operator, this paper draws from those experiences, then provides some rationale for extending the lessons learned during developmental flight research to the possible situations involved in the developmental flights proceeding deployed uninhabited tactical aircraft (UTA) operations. Two types of UTA control approaches are considered: autonomous and remotely piloted. In each of these cases, some level of human operator or pilot control blending is recommended. Additionally, "best practices" acquired over years of piloted aircraft experience are drawn from and presented as they apply to operational UTA.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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          Postscript (182 KBytes)
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    Report Date: April 1998
    No. Pages: 9
    Funding Organization: WU 529 31 94 00 XX 00 000
    Keywords:      Altus; Autonomous control; Flight test; Highly Maneuverable Aircraft Technology;HiMAT; Pathfinder; Perseus B; Remotely piloted vehicles; Uninhabited tacticalaircraft; Unmanned tactical aircraft; X-36 airplane
    Notes: Presented at the 8th Symposium on System Design Considerations for Uninhabited Tactical Aircraft, Athens,Greece, October 7-9, 1997.


  14. ON-LINE ROBUST MODAL STABILITY PREDICTION USING WAVELET PROCESSING , Technical Memorandum
    Authors: Martin J. Brenner and Rick Lind
    Report Number: NASA-TM-1998-206550
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Wavelet analysis for filtering and system identification has been used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins is reduced with parametric and nonparametric time-frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data is used to reduce the effects of external disturbances and unmodeled dynamics. Parametric estimates of modal stability are also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. The F-18 High Alpha Research Vehicle aeroservoelastic flight test data demonstrates improved robust stability prediction by extension of the stability boundary beyond the flight regime. Guidelines and computation times are presented to show the efficiency and practical aspects of these procedures for on-line implementation. Feasibility of the method is shown for processing flight data from time-varying nonstationary test points.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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    Report Date: September 1998
    No. Pages: 19
    Funding Organization: WU 529 50 04
    Keywords:      Aeroservoelasticity; Modal estimation; Robust stability; Uncertainty modeling;
    Notes: Presented at 21st International Council of the Aeronautical Sciences (ICAS) Congress, Melbourne, Australia, September 14-17, 1998, ICAS-98-4,9,1.


  15. DETERMINATION OF SUN ANGLES FOR OBSERVATIONS OF SHOCK WAVES ON A TRANSPORT AIRCRAFT , Technical Memorandum
    Authors: David F. Fisher , Edward A. Haering, Jr. , Gregory K. Noffz and Juan I. Aguilar
    Report Number: NASA-TM-1998-206551
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Wing compression shock shadowgraphs were observed on two flights during banked turns of an L-1011 aircraft at a Mach number of 0.85 and an altitude of 35,000 ft (10,700 m). Photos and video recording of the shadowgraphs were taken during the flights to document the shadowgraphs. Bright sunlight on the aircraft was required. The time of day, aircraft position, speed and attitudes were recorded to determine the sun azimuth and elevation relative to the wing quarter chordline when the shadowgraphs were visible. Sun elevation and azimuth angles were documented for which the wing compression shock shadowgraphs were visible. The shadowgraph was observed for high to low elevation angles relative to the wing, but for best results high sun angles relative to the wing are desired. The procedures and equations to determine the sun azimuth and elevation angle with respect to the quarter chordline is included in the Appendix.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 02
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          Postscript (488 KBytes)
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    Report Date: September 1998
    No. Pages: 19
    Funding Organization: WU 529 59 04 00 RR 00 000
    Keywords:      Flight test; Flow visualization; GPS; L-1011 aircraft; Shadowgraph; Shock waves
    Notes: Extended version of a conference paper presented at the 8th International Symposium on Flow Visualization,Sorrento, Italy, Sept. 1-4, 1998.


  16. FOREBODY FLOW VISUALIZATION ON THE F-18 HARV WITH ACTUATED FOREBODY STRAKES , Technical Memorandum
    Authors: David F. Fisher and Daniel G. Murri
    Report Number: NASA-TM-1998-206556
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Off-surface smoke flow visualization and extensive pressure measurements were obtained on the forebody of the NASA F-18 High Alpha Research Vehicle equipped with actuated forebody strakes. Test points at alpha = 50 deg were examined in which only one strake was deflected or in which both strakes were deflected differentially. The forebody pressures were integrated to obtain forebody yawing moments. Results showed that small single strake deflections can cause an undesirable yawing moment reversal. At alpha = 50 deg, this reversal was corrected by deploying both strakes at 20 deg initially, then differentially from 20 deg to create a yawing moment. The off-surface flow visualization showed that in the case of the small single strake deflection, the resulting forebody/strake vortex remained close to the surface and caused accelerated flow and increased suction pressures on the deflected side. When both strakes were deflected differentially, two forebody/strake vortices were present. The forebody/strake vortex from the larger deflection would lift from the surface while the other would remain close to the surface. The nearer forebody/strake vortex would cause greater flow acceleration, higher suction pressures and a yawing moment on that side of the forebody. Flow visualization provided a clear description of the strake vorticies fluid mechanics.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 02
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    Report Date: September 1998
    No. Pages: 15
    Funding Organization: WU 529-31-04-00-37-00-F18
    Keywords:      Aircraft; F-18; Flight; Flight Test; Flow visualization; Forebody; Smoke; Strake;
    Notes: Presented at the 8th International Symposium on Flow Visualization, Sorrento, Italy Sept. 1-4, 1998.


  17. REYNOLDS NUMBER EFFECTS AT HIGH ANGLES OF ATTACK , Technical Paper
    Authors: David F. Fisher, Brent R. Cobleigh, Daniel W. Banks, Robert M. Hall and Richard W. Wahls
    Report Number: NASA-TP-1998-206553
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Lessons learned from comparisons between ground-based tests and flight measurements for the high-angle-of- attack programs on the F-18 High Alpha Research Vehicle (HARV), the X-29 forward-swept wing aircraft, and the X-31 enhanced fighter maneuverability aircraft are presented. On all three vehicles, Reynolds number effects were evident on the forebodies at high angles of attack. The correlation between flight and wind tunnel forebody pressure distributions for the F-18 HARV were improved by using twin longitudinal grit strips on the forebody of the wind-tunnel model. Pressure distributions obtained on the X-29 wind-tunnel model at flight Reynolds numbers showed excellent correlation with the flight data up to alpha = 50 deg. Above alpha = 50 deg the pressure distributions for both flight and wind tunnel became asymmetric and showed poorer agreement, possibly because of the different surface finish of the model and aircraft. The detrimental effect of a very sharp nose apex was demonstrated on the X-31 aircraft. Grit strips on the forebody of the X-31 reduced the randomness but increased the magnitude of the asymmetry. Nose strakes were required to reduce the forebody yawing moment asymmetries and the grit strips on the flight test noseboom improved the aircraft handling qualities.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 02
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          Postscript (1,972 KBytes)
          PDF (536 KBytes)
    Report Date: June 1998
    No. Pages: 36
    Funding Organization: WU 529-50-04-00-RR-00-000
    Keywords:      Angle of attack; Flight test; Forebody; Noseboom; Reynolds number; Vortices;
    Notes: Presented at 20th AIAA Advanced Measurement and Ground Testing Technology Conference, Albuquerque, New Mexico, June 15-18, 1998, AIAA-98-2879 (Invited Paper).


  18. PROPULSION FLIGHT RESEARCH AT NASA DRYDEN FROM 1967 TO 1997 , Technical Paper
    Authors: Frank W. Burcham, Jr., Ronald J. Ray, Timothy R. Conners and Kevin R. Walsh
    Report Number: NASA-TP-1998-206554
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: From 1967 to 1997, pioneering propulsion flight research activities have been conceived and conducted at the NASA Dryden Flight Research Center. Many of these programs have been flown jointly with the United States Department of Defense, industry, or the Federal Aviation Administration. Propulsion research has been conducted on the XB-70, F-111A, F-111E, YF-12, JetStar, B-720, MD-11, F-15, F-104, Highly Maneuverable Aircraft Technology, F-14, F/A-18, SR-71, and the hypersonic X-15 airplanes. Research studies have included inlet dynamics and control, in-flight thrust computation, integrated propulsion controls, inlet and boattail drag, wind tunnel-to-flight comparisons, digital engine controls, advanced engine control optimization algorithms, acoustics, antimisting kerosene, in-flight lift and drag, throttle response criteria, and thrust-vectoring vanes. A computer-controlled thrust system has been developed to land the F-15 and MD-11 airplanes without using any of the normal flight controls. An F-15 airplane has flown tests of axisymmetric thrust-vectoring nozzles. A linear aerospike rocket experiment has been developed and tested on the SR-71 airplane. This paper discusses some of the more unique flight programs, the results, lessons learned, and their impact on current technology.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 07
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          Postscript (703 KBytes)
          PDF (275 KBytes)
    Report Date: July 1998
    No. Pages: 28
    Funding Organization: WU 523-90-24-00-RP-00-000
    Keywords:      Engine; Flight test; Inlet; Nozzle; Propulsion
    Notes: Presented at the AIAA/SAE/ASME/34th Joint Propulsion Conference, Cleveland, Ohio, July 13-15, 1998, AIAA 98-3712.


  19. THERMAL ANALYSIS OF A METALLIC WING GLOVE FOR A MACH-8 BOUNDARY-LAYER EXPERIMENT , Technical Memorandum
    Authors: Leslie Gong and W. Lance Richards
    Report Number: NASA-TM-1998-206555
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A metallic "glove" structure has been built and attached to the wing of the Pegasus ¨ space booster. An experiment on the upper surface of the glove has been designed to help validate boundary-layer stability codes in a free-flight environment. Three- dimensional thermal analyses have been performed to ensure that the glove structure design would be within allowable temperature limits in the experiment test section of the upper skin of the glove. Temperature results obtained from the design-case analysis show a peak temperature at the leading edge of 490 ¡F. For the upper surface of the glove, approximately 3ʩn. back from the leading edge, temperature calculations indicate transition occurs at approximately 45 sec into the flight profile. A worst-case heating analysis has also been performed to ensure that the glove structure would not have any detrimental effects on the primary objective of the Pegasus ¨ launch. A peak temperature of 805 ¡F has been calculated on the leading edge of the glove structure. The temperatures predicted from the design case are well within the temperature limits of the glove structure, and the worst- case heating analysis temperature results are acceptable for the mission objectives.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 34
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          Postscript (540 KBytes)
          PDF (190 KBytes)
    Report Date: June 1998
    No. Pages: 20
    Funding Organization: WU 529-60-24-00-17-00-DOC
    Keywords:      Aerodynamic heating; Boundary layer transition; Finite element modeling;
    Notes: Presented at 7th AIAA/AMSE Joint Thermophysics and Heat Transfer Conference, June 1518, 1998, AIAA-98-2580.


  20. SUMMARY OF INLET CHARACTERISTICS OF THE F/A-18A HIGH ALPHA RESEARCH VEHICLE , AIAA Conference Paper
    Authors: Kevin Walsh , William Steenken and John Williams
    Report Number: H-2260
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Effects of high-angle-of-attack flight on aircraft inlet aerodynamic characteristics were investigated at NASA Dryden Flight Research Center as part of NASA's High Alpha Technology Program. The highly instrumented F/A-18A High Alpha Research Vehicle was used for this research. A newly designed inlet total-pressure rake was installed in front of the right-hand F404-GE-400 engine to measure inlet recovery and distortion characteristics. Objectives included (1) determining the inlet total-pressure characteristics at steady high-angle-of- attack conditions, (2) assessing if inlet distortion is significantly different between rapid angle-of-attack maneuvers and corresponding steady aerodynamic conditions, (3) assessing inlet characteristics during aircraft departures, (4) providing data for developing and verifying computational fluid dynamic codes, and (5) calculating engine airflow using four methods for comparison with a reference method. This paper describes the results obtained from this investigation. These data and the associated database were rigorously validated to establish the foundation for understanding inlet characteristics at high angle of attack.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 07
    Availability:
        Format(s) on-line:
          Postscript (1,627 KBytes)
          PDF (402 KBytes)
    Report Date: July 1998
    No. Pages: 22
    Funding Organization: WU 529-31-04-00-37-00-F-18
    Keywords:      Aircraft departures; Computational fluid dynamics; F/A-18A airplane; GE404engine airflow; High angle of attack; Inlet distortion; Rapid angle-of-attackmaneuvers
    Notes: Presented at 34th Joint Propulsion Conference, Cleveland, Ohio, July 13-15, 1998, AIAA 98-3713. Kevin Walsh, NASA Dryden, William Steenken and John Williams, General Electric Aircraft Engines, Evandale, OH


  21. THE X-33 EXTENDED FLIGHT TEST RANGE , Technical Memorandum
    Authors: Dale A. Mackall, Robert Sakahara and Steven E. Kremer
    Report Number: NASA-TM-1998-206557
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Development of an extended test range, with range instrumentation providing continuous vehicle communications, is required to flight-test the X-33, a scaled version of a reusable launch vehicle. The extended test range provides vehicle communications coverage from California to landing at Montana or Utah. This paper provides an overview of the approaches used to meet X-33 program requirements, including using multiple ground stations, and methods to reduce problems caused by reentry plasma radio frequency blackout. The advances used to develop the extended test range show other hypersonic and access-to-space programs can benefit from the development of the extended test range.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 17
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          Postscript (321 KBytes)
          PDF (196 KBytes)
    Report Date: October 1998
    No. Pages: 16
    Funding Organization: WU 242-33-02-00-23-00-TA9
    Keywords:      Extended test range; Radio frequency communications; Reentry plasma blackout;Reusable Launch Vehicle; X-33
    Notes: Presented at 39th International Telemetry Conference, San Diego, CA, Oct. 26-29, 1998. Dale Mackall, NASA Dryden, Edwards, CA; Robert Sakahara, Air Force Flight Test Center, Edwards,CA; Steven Kremer, NASA Goddard, Wallops Island, VA.


  22. FULL FLIGHT ENVELOPE DIRECT THRUST MEASUREMENT ON A SUPERSONIC AIRCRAFT , Technical Memorandum
    Authors: Timothy R. Conners and Robert L. Sims
    Report Number: NASA-TM-1998-206560
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Direct thrust measurement using strain gages offers advantages over analytically-based thrust calculation methods. For flight test applications, the direct measurement method typically uses a simpler sensor arrangement and minimal data processing compared to analytical techniques, which normally require costly engine modeling and multisensor arrangements throughout the engine. Conversely, direct thrust measurement has historically produced less than desirable accuracy because of difficulty in mounting and calibrating the strain gages and the inability to account for secondary forces that influence the thrust reading at the engine mounts. Consequently, the strain-gage technique has normally been used for simple engine arrangements and primarily in the subsonic speed range. This paper presents the results of a strain gage-based direct thrust-measurement technique developed by the NASA Dryden Flight Research Center and successfully applied to the full flight envelope of an F-15 aircraft powered by two F100-PW-229 turbofan engines. Measurements have been obtained at quasi-steady-state operating conditions at maximum nonaugmented and maximum augmented power throughout the altitude range of the vehicle and to a maximum speed of Mach 2.0, and are compared against results from two analytically-based thrust calculation methods. The strain-gage installation and calibration processes are also described.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
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          PDF (597 KBytes)
    Report Date: July 1998
    No. Pages: 37
    Funding Organization: WU 529-20-04-00-33-00-MGT
    Keywords:      Accuracy; Analytical models; Calibration; Direct thrust measurement; F-15; F100-PW-229 engine; Strain gage; Supersonic; Thrust calculation
    Notes: Presented at the 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Cleveland, Ohio, July 13-15, 1998, AIAA 98-3872.


  23. INITIAL FLIGHT TEST EVALUATION OF THE F-15 ACTIVE AXISYMMETRIC VECTORING NOZZLE PERFORMANCE , Technical Memorandum
    Authors: John S. Orme , Ross Hathaway and Michael D. Ferguson
    Report Number: NASA-TM-1998-206558
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A full envelope database of a thrust-vectoring axisymmetric nozzle performance for the Pratt & Whitney Pitch/Yaw Balance Beam Nozzle (P/YBBN) is being developed using the F-15 Advanced Control Technology for Integrated Vehicles (ACTIVE) aircraft. At this time, flight research has been completed for steady-state pitch vector angles up to 20 degrees at an altitude of 30,000 ft from low power settings to maximum afterburner power. The nozzle performance database includes vector forces, internal nozzle pressures, and temperatures all of which can be used for regression analysis modeling. The database was used to substantiate a set of nozzle performance data from wind tunnel testing and computational fluid dynamic analyses. Findings from initial flight research at Mach 0.9 and 1.2 are presented in this paper. The results show that vector efficiency is strongly influenced by power setting. A significant discrepancy in nozzle performance has been discovered between predicted and measured results during vectoring.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05, 07
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        Format(s) on-line:
          Postscript (565 KBytes)
          PDF (272 KBytes)
    Report Date: July 1998
    No. Pages: 23
    Funding Organization: WU 529-50-40-00-32-00-001
    Notes: Presented at 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conf., Cleveland, OH, July 13-15, 1998. John Orme, NASA Dryden, Edwards, CA; Ross Hathaway, AS&M, Edwards, CA; Michael Ferguson, United Technologies Corp., P&W, West Palm Beach, FL.


  24. LINEAR AEROSPIKE SR-71 EXPERIMENT (LASRE): AEROSPACE PROPULSION HAZARD MITIGATION SYSTEMS , Technical Memorandum
    Authors: Masashi Mizukami , Griffin P. Corpening , Ronald J. Ray , Neal Hass , Kimberly A. Ennix and Scott M. Lazaroff
    Report Number: NASA-TM-1998-206561
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: A major hazard posed by the propulsion system of hypersonic and space vehicles is the possibility of fire or explosion in the vehicle environment. The hazard is mitigated by minimizing or detecting, in the vehicle environment, the three ingredients essential to producing fire: fuel, oxidizer, and an ignition source. The Linear Aerospike SR-71 Experiment (LASRE) consisted of a linear aerospike rocket engine integrated into one-half of an X-33-like lifting body shape, carried on top of an SR-71 aircraft. Gaseous hydrogen and liquid oxygen were used as propellants. Although LASRE is a one-of-a-kind experimental system, it must be rated for piloted flight, so this test presented a unique challenge. To help meet safety requirements, the following propulsion hazard mitigation systems were incorporated into the experiment: pod inert purge, oxygen sensors, a hydrogen leak detection algorithm, hydrogen sensors, fire detection and pod temperature thermocouples, water misting, and control room displays. These systems are described, and their development discussed. Analyses, ground test, and flight test results are presented, as are findings and lessons learned.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 20
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          Postscript (1,269 KBytes)
          PDF (569 KBytes)
    Report Date: July 1998
    No. Pages: 21
    Funding Organization: WU 242-33-02-00-33-00-T15
    Keywords:      Fire prevention; Flight safety; Hypersonic vehicles; Reusable launch vehicles;
    Notes: Presented at 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conf., Cleveland, OH, July 13-15, 1998. M. Mizukami, G. Corpening, R. Ray, N. Hass and K. Ennix, NASA Dryden, Edwards, CA; S. Lazaroff, NASA Johnson Space Center, Houston, TX.


  25. DEVELOPMENT AND TESTING OF A HIGH STABILITY ENGINE CONTROL (HISTEC) SYSTEM , Technical Memorandum
    Authors: John S. Orme , John C. DeLaat , Robert D. Southwick , George W. Gallops and Paul M. Doane
    Report Number: NASA-TM-1998-206562
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Flight tests were recently completed to demonstrate an inlet-distortion-tolerant engine control system. These flight tests were part of NASA's High Stability Engine Control (HISTEC) program. The objective of the HISTEC program was to design, develop, and flight demonstrate an advanced integrated engine control system that uses measurement-based, real-time estimates of inlet airflow distortion to enhance engine stability. With improved stability and tolerance of inlet airflow distortion, future engine designs may benefit from a reduction in design stall-margin requirements and enhanced reliability, with a corresponding increase in performance and decrease in fuel consumption. This paper describes the HISTEC methodology, presents an aircraft test bed description (including HISTEC-specific modifications) and verification and validation ground tests. Additionally, flight test safety considerations, test plan and technique design and approach, and flight operations are addressed. Some illustrative results are presented to demonstrate the type of analysis and results produced from the flight test program.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05, 07
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          Postscript (480 KBytes)
          PDF (216 KBytes)
    Report Date: July 1998
    No. Pages: 18
    Funding Organization: WU 529-20-04-00-33-00-MGT
    Keywords:      Air data; Avionics; Controls; Engine control; Engine stability; F-15 ACTIVE;
    Notes: Presented at 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conf., Cleveland, OH, July 13-15, 1998. J. Orme, NASA Dryden; J. DeLaat, NASA Lewis; R. Southwick and G. Gallops, United Tech. Corp., P&W, W. Palm Beach, FL, P. Doane, Boeing Phantom, St. Louis, MO.


  26. CONVERSION FROM ENGINEERING UNITS TO TELEMETRY COUNTS ON DRYDEN FLIGHT SIMULATIONS , Contractor Report
    Authors: Jay A. Fantini
    Report Number: NASA-CR-1998-206563
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: Dryden real-time flight simulators encompass the simulation of pulse code modulation (PCM) telemetry signals. This paper presents a new method whereby the calibration polynomial (from first to sixth order), representing the conversion from counts to engineering units (EU), is numerically inverted in real time. The result is less than one-count error for valid EU inputs. The Newton-Raphson method is used to numerically invert the polynomial. A reverse linear interpolation between the EU limits is used to obtain an initial value for the desired telemetry count. The method presented here is not new. What is new is how classical numerical techniques are optimized to take advantage of modern computer power to perform the desired calculations in real time. This technique makes the method simple to understand and implement. There are no interpolation tables to store in memory as in traditional methods. The NASA F-15 simulation converts and transmits over 1000 parameters at 80 times/sec. This paper presents algorithm development, FORTRAN code, and performance results.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 61
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          Postscript (203 KBytes)
          PDF (95 KBytes)
    Report Date: October 1998
    No. Pages: 16
    Keywords:      Flight Simulators; Fortran; Newton-Raphson Method; Numerical Analysis;
    Notes: Presented at the 34th International Telemetry Conference, San Diego, California, October 26-28, 1998. Technical Monitor, Brian Curtlett, NASA Dryden. WU 314-02-000-FR-00-ITG


  27. X-33 INTEGRATED TEST FACILITY EXTENDED RANGE SIMULATION , Technical Memorandum
    Authors: Ashley Sharma
    Report Number: NASA-TM-1998-206564
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: In support of the X-33 single-stage-to-orbit program, NASA Dryden Flight Research Center was selected to provide continuous range communications of the X-33 vehicle from launch at Edwards Air Force Base, California, through landing at Malmstrom Air Force Base, Montana, or at Michael Army Air Field, Utah. An extensive real-time range simulation capability is being developed to ensure successful communications with the autonomous X-33 vehicle. This paper provides an overview of the various levels of simulation, integration, and test being developed to support the X-33 extended range subsystems. These subsystems include the flight termination system, L-band command uplink subsystem, and S-band telemetry downlink subsystem.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 61
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        Format(s) on-line:
          Postscript (267 KBytes)
          PDF (123 KBytes)
    Report Date: October 1998
    No. Pages: 15
    Funding Organization: WU 242-33-02-00-23-00-TA9
    Keywords:      Dynamic Ground Station Analysis; Integration and Test Facility; Link Margin;
    Notes: Presented at the 34th International Telemetry Conference, San Diego, California, October 26-29, 1998.


  28. FLIGHT STABILITY AND CONTROL AND PERFORMANCE RESULTS FROM THE LINEAR AEROSPIKE SR-71 EXPERIMENT (LASRE) , Technical Memorandum
    Authors: Timothy R. Moes , Brent R. Cobleigh , Timothy H. Cox , Timothy R. Conners , Kenneth W. Iliff and Bruce G. Powers
    Report Number: NASA-TM-1998-206565
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The Linear Aerospike SR-71 Experiment (LASRE) is presently being conducted to test a 20-percent-scale version of the Linear Aerospike rocket engine. This rocket engine has been chosen to power the X-33 Single Stage to Orbit Technology Demonstrator Vehicle. The rocket engine was integrated into a lifting body configuration and mounted to the upper surface of an SR-71 aircraft. This paper presents stability and control results and performance results from the envelope expansion flight tests of the LASRE configuration up to Mach 1.8 and compares the results with wind tunnel predictions. Longitudinal stability and elevator control effectiveness were well-predicted from wind tunnel tests. Zero-lift pitching moment was mispredicted transonically. Directional stability, dihedral stability, and rudder effectiveness were overpredicted. The SR-71 handling qualities were never significantly impacted as a result of the missed predictions. Performance results confirmed the large amount of wind-tunnel-predicted transonic drag for the LASRE configuration. This drag increase made the performance of the vehicle so poor that acceleration through transonic Mach numbers could not be achieved on a hot day without depleting the available fuel.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 08
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          Postscript (835 KBytes)
          PDF (427 KBytes)
    Report Date: August 1998
    No. Pages: 32
    Funding Organization: WU 244-33-02-00-23-00-T15
    Keywords:      Aerospike rocket; Flight test; LASRE; SR-71; Stability and control
    Notes: Presented at the AIAA Atmospheric Flight Mechanics Conference, August 10-12, 1998, Boston, MA. Timothy Moes, Brent Cobleigh, Timothy Cox, Timothy Conners, and Kenneth Iliff, NASA Dryden, Edwards, CA; and Bruce Powers, AS&M, Inc., Edwards, CA.


  29. AN OVERVIEW OF AN EXPERIMENTAL DEMONSTRATION AEROTOW PROGRAM , Technical Memorandum
    Authors: James E. Murray, Albion H. Bowers, William A. Lokos, Todd L. Peters and Joseph Gera
    Report Number: NASA-TM-1998-206566
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: An overview of an experimental demonstration of aerotowing a delta-wing airplane with low-aspect ratio and relatively high wing loading is presented. Aerotowing of future space launch configurations is a new concept, and the objective of the work described herein is to demonstrate the aerotow operation using an airplane configuration similar to conceptual space launch vehicles. Background information on the use of aerotow for a space launch vehicle is presented, and the aerotow system used in this demonstration is described. The ground tests, analytical studies, and flight planning used to predict system behavior and to enhance flight safety are detailed. The instrumentation suite and flight test maneuvers flown are discussed, preliminary performance is assessed, and flight test results are compared with the preflight predictions.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 05
    Availability:
        Format(s) on-line:
          Postscript (3,637 KBytes)
          PDF (1,404 KBytes)
    Report Date: September 1998
    No. Pages: 28
    Funding Organization: WU 242-33-02-00-25-00-000
    Keywords:      ECLIPSE; Tethered aircraft; Towed aircraft; Towing aircraft; Towed system
    Notes: Presented at 30th Anniversary Symposium of the Society of Flight Test Engineers, Inc., September 15-17, 1998, Reno, NV. James Murray, Albion Bowers, William Lokos, Todd Peters, NASA Dryden, Edwards, CA; Joseph Gera, AS&M, Inc., Edwards, CA.


  30. FLIGHT TESTING THE LINEAR AEROSPIKE SR-71 EXPERIMENT (LASRE) , Technical Memorandum
    Authors: Stephen Corda, Bradford A. Neal, Timothy R. Moes, Timothy H. Cox, Richard C. Monaghan, Leonard S. Voelker, Griffin P. Corpening, Richard R. Larson and Bruce G. Powers
    Report Number: NASA-TM-1998-206567
    Performing Organization: NASA Dryden Flight Research Center, Edwards, CA
    Abstract: The design of the next generation of space access vehicles has led to a unique flight test that blends the space and flight research worlds. The new space vehicle designs, such as the X-33 vehicle and Reusable Launch Vehicle (RLV), are powered by linear aerospike rocket engines. Conceived of in the 1960's, these aerospike engines have yet to be flown, and many questions remain regarding aerospike engine performance and efficiency in flight. To provide some of these data before flying on the X-33 vehicle and the RLV, a spacecraft rocket engine has been flight-tested atop the NASA SR-71 aircraft as the Linear Aerospike SR-71 Experiment (LASRE). A 20 percent-scale, semispan model of the X-33 vehicle, the aerospike engine, and all the required fuel and oxidizer tanks and propellant feed systems have been mounted atop the SR-71 airplane for this experiment. A major technical objective of the LASRE flight test is to obtain installed-engine performance flight data for comparison to wind-tunnel results and for the development of computational fluid dynamics- based design methodologies. The ultimate goal of firing the aerospike rocket engine in flight is still forthcoming. An extensive design and development phase of the experiment hardware has been completed, including approximately 40 ground tests. Five flights of the LASRE and firing the rocket engine using inert liquid nitrogen and helium in place of liquid oxygen and hydrogen have been successfully completed.
    Distribution/Availability: Unclassified - Unlimited
    Subject Category: 07
    Availability:
        Format(s) on-line:
          Postscript (844 KBytes)
          PDF (338 KBytes)
    Report Date: September 1998
    No. Pages: 26
    Funding Organization: WU 242-33-02-00-23-T15
    Keywords:      Flight test; Flight tests using hydrogen fuel; Linear aerospike rocket engines;SR-71; X-33 space vehicle.
    Notes: Presented at 30th Anniversary Symposium of the Society of Flight Test Engineers, Sept. 15-17, 1998, Reno, NV. S. Corda, B. Neal, T. Moes, T. Cox, R. Monaghan, L.Voelker, G. Corpening, R. Larson, NASA Dryden, Edwards, CA; B. Powers, AS&M, Hampton, VA.
 
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