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Sample records for airframe program acap

  1. Advanced composite airframe program: Today's technology

    NASA Technical Reports Server (NTRS)

    Good, Danny E.; Mazza, L. Thomas

    1988-01-01

    The Advanced Composite Airframe Program (ACAP) was undertaken to demonstrate the advantages of the application of advanced composite materials and structural design concepts to the airframe structure on helicopters designed to stringent military requirements. The primary goals of the program were the reduction of airframe production costs and airframe weight by 17 and 22 percent respectively. The ACAP effort consisted of a preliminary design phase, detail design, and design support testing, full-scale fabrication, laboratory testing, and a ground/flight test demonstration. Since the completion of the flight test demonstration programs follow-on efforts were initiated to more fully evaluate a variety of military characteristics of the composite airframe structures developed under the original ACAP advanced development contracts. An overview of the ACAP program is provided and some of the design features, design support testing, manufacturing approaches, and the results of the flight test evaluation, as well as, an overview of Militarization Test and Evaluation efforts are described.

  2. Advanced Control and Power System (ACAPS) technology program

    SciTech Connect

    Keckler, C.R.; Groom, N.J.

    1983-12-01

    The Advanced Control and Power System (ACAPS) program is to establish the technology necessary to satisfy space station and related large space structures requirements for efficient, reliable, and cost effective energy storage and attitude control. Technology advances in the area of integrated flywheel systems capable of performing the dual functions of energy storage and attitude control are outlined.

  3. Advanced Control and Power System (ACAPS) Technology Program

    NASA Technical Reports Server (NTRS)

    Keckler, C. R.; Groom, N. J.

    1983-01-01

    The advanced control and power system (ACAPS) program is to establish the technology necessary to satisfy space station and related large space structures requirements for efficient, reliable, and cost effective energy storage and attitude control. Technology advances in the area of integrated flywheel systems capable of performing the dual functions of energy storage and attitude control are outlined.

  4. The Aviation Careers Accessibility Program (ACAP) at Florida Memorial College. Final Report.

    ERIC Educational Resources Information Center

    Florida Memorial Coll., Miami.

    This project, referred to as the Aviation Careers Accessibility Program (ACAP) established a model program for inner-city minority high school students that would allow them information and accessibility to careers and opportunities in the aviation industry. The project featured two program components: an academic year component during and a 5- or…

  5. The Integrated Airframe/Propulsion Control System Architecture program (IAPSA)

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.; Cohen, Gerald C.; Meissner, Charles W.

    1990-01-01

    The Integrated Airframe/Propulsion Control System Architecture program (IAPSA) is a two-phase program which was initiated by NASA in the early 80s. The first phase, IAPSA 1, studied different architectural approaches to the problem of integrating engine control systems with airframe control systems in an advanced tactical fighter. One of the conclusions of IAPSA 1 was that the technology to construct a suitable system was available, yet the ability to create these complex computer architectures has outpaced the ability to analyze the resulting system's performance. With this in mind, the second phase of IAPSA approached the same problem with the added constraint that the system be designed for validation. The intent of the design for validation requirement is that validation requirements should be shown to be achievable early in the design process. IAPSA 2 has demonstrated that despite diligent efforts, integrated systems can retain characteristics which are difficult to model and, therefore, difficult to validate.

  6. Occupant Responses in a Full-Scale Crash Test of the Sikorsky ACAP Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; McEntire, Joseph; Lewis, Alan

    2002-01-01

    A full-scale crash test of the Sikorsky Advanced Composite Airframe Program (ACAP) helicopter was performed in 1999 to generate experimental data for correlation with a crash simulation developed using an explicit nonlinear, transient dynamic finite element code. The airframe was the residual flight test hardware from the ACAP program. For the test, the aircraft was outfitted with two crew and two troop seats, and four anthropomorphic test dummies. While the results of the impact test and crash simulation have been documented fairly extensively in the literature, the focus of this paper is to present the detailed occupant response data obtained from the crash test and to correlate the results with injury prediction models. These injury models include the Dynamic Response Index (DRI), the Head Injury Criteria (HIC), the spinal load requirement defined in FAR Part 27.562(c), and a comparison of the duration and magnitude of the occupant vertical acceleration responses with the Eiband whole-body acceleration tolerance curve.

  7. Airframe Noise Results from the QTD II Flight Test Program

    NASA Technical Reports Server (NTRS)

    Elkoby, Ronen; Brusniak, Leon; Stoker, Robert W.; Khorrami, Mehdi R.; Abeysinghe, Amal; Moe, Jefferey W.

    2007-01-01

    With continued growth in air travel, sensitivity to community noise intensifies and materializes in the form of increased monitoring, regulations, and restrictions. Accordingly, realization of quieter aircraft is imperative, albeit only achievable with reduction of both engine and airframe components of total aircraft noise. Model-scale airframe noise testing has aided in this pursuit; however, the results are somewhat limited due to lack of fidelity of model hardware, particularly in simulating full-scale landing gear. Moreover, simulation of true in-flight conditions is non-trivial if not infeasible. This paper reports on an investigation of full-scale landing gear noise measured as part of the 2005 Quiet Technology Demonstrator 2 (QTD2) flight test program. Conventional Boeing 777-300ER main landing gear were tested, along with two noise reduction concepts, namely a toboggan fairing and gear alignment with the local flow, both of which were down-selected from various other noise reduction devices evaluated in model-scale testing at Virginia Tech. The full-scale toboggan fairings were designed by Goodrich Aerostructures as add-on devices allowing for complete retraction of the main gear. The baseline-conventional gear, faired gear, and aligned gear were all evaluated with the high-lift system in the retracted position and deployed at various flap settings, all at engine idle power setting. Measurements were taken with flyover community noise microphones and a large aperture acoustic phased array, yielding far-field spectra, and localized sources (beamform maps). The results were utilized to evaluate qualitatively and quantitatively the merit of each noise reduction concept. Complete similarity between model-scale and full-scale noise reduction levels was not found and requires further investigation. Far-field spectra exhibited no noise reduction for both concepts across all angles and frequencies. Phased array beamform maps show inconclusive evidence of noise

  8. Coupled rotor/airframe vibration analysis program manual manual. Volume 1: User's and programmer's instructions

    NASA Technical Reports Server (NTRS)

    Cassarino, S.; Sopher, R.

    1982-01-01

    user instruction and software descriptions for the base program of the coupled rotor/airframe vibration analysis are provided. The functional capabilities and procedures for running the program are provided. Interfaces with external programs are discussed. The procedure of synthesizing a dynamic system and the various solution methods are described. Input data and output results are presented. Detailed information is provided on the program structure. Sample test case results for five representative dynamic configurations are provided and discussed. System response are plotted to demonstrate the plots capabilities available. Instructions to install and execute SIMVIB on the CDC computer system are provided.

  9. Environmental effects on composite airframes: A study conducted for the ARM UAV Program (Atmospheric Radiation Measurement Unmanned Aerospace Vehicle)

    SciTech Connect

    Noguchi, R.A.

    1994-06-01

    Composite materials are affected by environments differently than conventional airframe structural materials are. This study identifies the environmental conditions which the composite-airframe ARM UAV may encounter, and discusses the potential degradation processes composite materials may undergo when subjected to those environments. This information is intended to be useful in a follow-on program to develop equipment and procedures to prevent, detect, or otherwise mitigate significant degradation with the ultimate goal of preventing catastrophic aircraft failure.

  10. Nondestructive Evaluation (NDE) Results on Sikorsky Aircraft Survivable Affordable Reparable Airframe Program (SARAP) Samples

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Anastasi, Robert F.; Madaras, Eric I.

    2004-01-01

    The Survivable, Affordable, Reparable Airframe Program (SARAP) will develop/produce new structural design concepts with lower structural weight, reduced manufacturing complexity and development time, increased readiness, and improved threat protection. These new structural concepts will require advanced field capable inspection technologies to help meet the SARAP structural objectives. In the area of repair, damage assessment using nondestructive inspection (NDI) is critical to identify repair location and size. The purpose of this work is to conduct an assessment of new and emerging NDI methods that can potentially satisfy the SARAP program goals.

  11. Coupled rotor/airframe vibration analysis program manual. Volume 2: Sample input and output listings

    NASA Technical Reports Server (NTRS)

    Cassarino, S.; Sopher, R.

    1982-01-01

    Sample input and output listings obtained with the base program (SIMVIB) of the coupled rotor/airframe vibration analysis and the external programs, G400/F389 and E927 are presented. Results for five of the base program test cases are shown. They represent different applications of the SIMVIB program to study the vibration characteristics of various dynamic configurations. Input and output listings obtained for one cycle of the G400/F389 coupled program are presented. Results from the rotor aeroelastic analysis E927 also appear. A brief description of the check cases is provided. A summary of the check cases for all the external programs interacting with the SIMVIB program is illustrated.

  12. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: Boeing Helicopters airframe finite element modeling

    NASA Technical Reports Server (NTRS)

    Gabel, R.; Lang, P.; Reed, D.

    1993-01-01

    Mathematical models based on the finite element method of structural analysis, as embodied in the NASTRAN computer code, are routinely used by the helicopter industry to calculate airframe static internal loads used for sizing structural members. Historically, less reliance has been placed on the vibration predictions based on these models. Beginning in the early 1980's NASA's Langley Research Center initiated an industry wide program with the objective of engendering the needed trust in vibration predictions using these models and establishing a body of modeling guides which would enable confident future prediction of airframe vibration as part of the regular design process. Emphasis in this paper is placed on the successful modeling of the Army/Boeing CH-47D which showed reasonable correlation with test data. A principal finding indicates that improved dynamic analysis requires greater attention to detail and perhaps a finer mesh, especially the mass distribution, than the usual stress model. Post program modeling efforts show improved correlation placing key modal frequencies in the b/rev range with 4 percent of the test frequencies.

  13. Proceedings of the Airframe Icing Workshop

    NASA Technical Reports Server (NTRS)

    Colantonio, Ron O. (Editor)

    2009-01-01

    The NASA Glenn Research Center (GRC) has a long history of working with its partners towards the understanding of ice accretion formation and its associated degradation of aerodynamic performance. The June 9, 2009, Airframe Icing Workshop held at GRC provided an opportunity to examine the current NASA airframe icing research program and to dialogue on remaining and emerging airframe icing issues and research with the external community. Some of the airframe icing gaps identified included, but are not limited to, ice accretion simulation enhancements, three-dimensional benchmark icing database development, three-dimensional iced aerodynamics modeling, and technology development for a smart icing system.

  14. Rationale and design for the Asymptomatic Carotid Artery Plaque Study (ACAPS). The ACAPS Group.

    PubMed

    1992-08-01

    An NHLBI-sponsored randomized, double-masked, placebo-controlled, multicenter clinical trial is underway to test the efficacy of the lipid-lowering agent lovastatin and/or the antithrombotic agent warfarin in slowing the progression of early carotid atherosclerosis--as defined by ultrasonographic intimal-medial arterial wall thickening--in a high-risk, asymptomatic population consisting of 919 men and women aged 40-79 years with moderately elevated serum LDL-cholesterol. The Asymptomatic Carotid Artery Plaque Study's (ACAPS) factorial design permits evaluation of each of the two treatments alone as well as assessment of the treatments in combination with each other over a 2.5- to 3.0-year treatment period. Randomized participants receive either 20-40 mg/day lovastatin or lovastatin placebo and either 1 mg/day (minidose) warfarin or warfarin placebo. All participants were encouraged to take low-dose (81 mg/day) aspirin. The primary outcome is the ultrasonographic measurement of the mean of maximum intimal-medial thickness (IMT) across up to 12 preselected segments in the carotid arteries. The secondary outcome of the trial measures the single maximum IMT measurement among the same preselected carotid artery segments. This report describes the rationale for ACAPS, its design, and some baseline characteristics of the study population.

  15. Airframe Noise Studies: Review and Future Direction

    NASA Technical Reports Server (NTRS)

    Rackl, Robert G.; Miller, Gregory; Guo, Yueping; Yamamoto, Kingo

    2005-01-01

    This report contains the following information: 1) a review of airframe noise research performed under NASA's Advanced Subsonic Transport (AST) program up to the year 2000, 2) a comparison of the year 1992 airframe noise predictions with those using a year 2000 baseline, 3) an assessment of various airframe noise reduction concepts as applied to the year 2000 baseline predictions, and 4) prioritized recommendations for future airframe noise reduction work. NASA's Aircraft Noise Prediction Program was the software used for all noise predictions and assessments. For future work, the recommendations for the immediate future focus on the development of design tools sensitive to airframe noise treatment effects and on improving the basic understanding of noise generation by the landing gear as well as on its reduction.

  16. Human ACAP2 is a homolog of C. elegans CNT-1 that promotes apoptosis in cancer cells

    PubMed Central

    Sullivan, Kelly D.; Nakagawa, Akihisa; Xue, Ding; Espinosa, Joaquín M

    2015-01-01

    Activation of caspases is an integral part of the apoptotic cell death program. Collectively, these proteases target hundreds of substrates, leading to the hypothesis that apoptosis is “death by a thousand cuts”. Recent work, however, has demonstrated that caspase cleavage of only a subset of these substrates directs apoptosis in the cell. One such example is C. elegans CNT-1, which is cleaved by CED-3 to generate a truncated form, tCNT-1, that acquires a potent phosphoinositide-binding activity and translocates to the plasma membrane where it inactivates AKT survival signaling. We report here that ACAP2, a homolog of C. elegans CNT-1, has a pro-apoptotic function and an identical phosphoinositide-binding pattern to that of tCNT-1, despite not being an apparent target of caspase cleavage. We show that knockdown of ACAP2 blocks apoptosis in cancer cells in response to the chemotherapeutic antimetabolite 5-fluorouracil and that ACAP2 expression is down-regulated in some esophageal cancers, leukemias and lymphomas. These results suggest that ACAP2 is a functional homolog of C. elegans CNT-1 and its inactivation or downregulation in human cells may contribute to cancer development. PMID:25853217

  17. Development of the NASA/FLAGRO computer program for analysis of airframe structures

    NASA Technical Reports Server (NTRS)

    Forman, R. G.; Shivakumar, V.; Newman, J. C., Jr.

    1994-01-01

    The NASA/FLAGRO (NASGRO) computer program was developed for fracture control analysis of space hardware and is currently the standard computer code in NASA, the U.S. Air Force, and the European Agency (ESA) for this purpose. The significant attributes of the NASGRO program are the numerous crack case solutions, the large materials file, the improved growth rate equation based on crack closure theory, and the user-friendly promptive input features. In support of the National Aging Aircraft Research Program (NAARP); NASGRO is being further developed to provide advanced state-of-the-art capability for damage tolerance and crack growth analysis of aircraft structural problems, including mechanical systems and engines. The project currently involves a cooperative development effort by NASA, FAA, and ESA. The primary tasks underway are the incorporation of advanced methodology for crack growth rate retardation resulting from spectrum loading and improved analysis for determining crack instability. Also, the current weight function solutions in NASGRO or nonlinear stress gradient problems are being extended to more crack cases, and the 2-d boundary integral routine for stress analysis and stress-intensity factor solutions is being extended to 3-d problems. Lastly, effort is underway to enhance the program to operate on personal computers and work stations in a Windows environment. Because of the increasing and already wide usage of NASGRO, the code offers an excellent mechanism for technology transfer for new fatigue and fracture mechanics capabilities developed within NAARP.

  18. ACAPs are arf6 GTPase-activating proteins that function in the cell periphery.

    PubMed

    Jackson, T R; Brown, F D; Nie, Z; Miura, K; Foroni, L; Sun, J; Hsu, V W; Donaldson, J G; Randazzo, P A

    2000-10-30

    The GTP-binding protein ADP-ribosylation factor 6 (Arf6) regulates endosomal membrane trafficking and the actin cytoskeleton in the cell periphery. GTPase-activating proteins (GAPs) are critical regulators of Arf function, controlling the return of Arf to the inactive GDP-bound state. Here, we report the identification and characterization of two Arf6 GAPs, ACAP1 and ACAP2. Together with two previously described Arf GAPs, ASAP1 and PAP, they can be grouped into a protein family defined by several common structural motifs including coiled coil, pleckstrin homology, Arf GAP, and three complete ankyrin-repeat domains. All contain phosphoinositide-dependent GAP activity. ACAP1 and ACAP2 are widely expressed and occur together in the various cultured cell lines we examined. Similar to ASAP1, ACAP1 and ACAP2 were recruited to and, when overexpressed, inhibited the formation of platelet-derived growth factor (PDGF)-induced dorsal membrane ruffles in NIH 3T3 fibroblasts. However, in contrast with ASAP1, ACAP1 and ACAP2 functioned as Arf6 GAPs. In vitro, ACAP1 and ACAP2 preferred Arf6 as a substrate, rather than Arf1 and Arf5, more so than did ASAP1. In HeLa cells, overexpression of either ACAP blocked the formation of Arf6-dependent protrusions. In addition, ACAP1 and ACAP2 were recruited to peripheral, tubular membranes, where activation of Arf6 occurs to allow membrane recycling back to the plasma membrane. ASAP1 did not inhibit Arf6-dependent protrusions and was not recruited by Arf6 to tubular membranes. The additional effects of ASAP1 on PDGF-induced ruffling in fibroblasts suggest that multiple Arf GAPs function coordinately in the cell periphery.

  19. The NASA/Industry Design Analysis Methods for Vibrations (DAMVIBS) Program - Boeing helicopters airframe finite element modeling

    NASA Technical Reports Server (NTRS)

    Gabel, R.; Lang, P.; Reed, D.

    1992-01-01

    Finite-element modeling of the airframe vibration of the Army/Boeing CH-47D helicopter is conducted with comparisons to experimental data in an effort to improve the design process. A NASTRAN FEM is developed that is fully representative of the test configuration and includes the support fixture, shakers, and the aircraft/shaker suspension system. The analysis is conducted with specific attention given to the prediction of reasonable forced amplitudes throughout the airframe. Reasonable correlation is noted between the FEM and experimental results, although improved correlation can be obtained by including more accurate damping values and secondary effects such as stringer shear loading. It is shown that the general stress model does not provide an adequate dynamic analysis on which to base design improvements. A more detailed model is required that emphasizes highly detailed helicopter elements and employs a finer mesh particularly in the description of the mass distribution.

  20. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: Sikorsky Aircraft: Advances toward interacting with the airframe design process

    NASA Technical Reports Server (NTRS)

    Twomey, William J.

    1993-01-01

    A short history is traced of the work done at Sikorsky Aircraft under the NASA/industry DAMVIBS program. This includes both work directly funded by the program as well as work which was internally funded but which received its initial impetus from DAMVIBS. The development of a finite element model of the UH-60A airframe having a marked improvement in vibration-predicting ability is described. A new program, PAREDYM, developed at Sikorsky, which automatically adjusts an FEM so that its modal characteristics match test values, is described, as well as the part this program played in the improvement of the UH-60A model. Effects of the bungee suspension system on the shake test data used for model verification are described. The impetus given by the modeling improvement, as well as the recent availability of PAREDYM, has brought for the first time the introduction of low-vibration design into the design cycle at Sikorsky.

  1. Airframe noise prediction evaluation

    NASA Technical Reports Server (NTRS)

    Yamamoto, Kingo J.; Donelson, Michael J.; Huang, Shumei C.; Joshi, Mahendra C.

    1995-01-01

    The objective of this study is to evaluate the accuracy and adequacy of current airframe noise prediction methods using available airframe noise measurements from tests of a narrow body transport (DC-9) and a wide body transport (DC-10) in addition to scale model test data. General features of the airframe noise from these aircraft and models are outlined. The results of the assessment of two airframe prediction methods, Fink's and Munson's methods, against flight test data of these aircraft and scale model wind tunnel test data are presented. These methods were extensively evaluated against measured data from several configurations including clean, slat deployed, landing gear-deployed, flap deployed, and landing configurations of both DC-9 and DC-10. They were also assessed against a limited number of configurations of scale models. The evaluation was conducted in terms of overall sound pressure level (OASPL), tone corrected perceived noise level (PNLT), and one-third-octave band sound pressure level (SPL).

  2. Airframe Technology Development for Next Generation Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Glass, David E.

    2004-01-01

    The Airframe subproject within NASA's Next Generation Launch Technology (NGLT) program has the responsibility to develop airframe technology for both rocket and airbreathing vehicles for access to space. The Airframe sub-project pushes the state-of-the-art in airframe technology for low-cost, reliable, and safe space transportation. Both low and medium technology readiness level (TRL) activities are being pursued. The key technical areas being addressed include design and integration, hot and integrated structures, cryogenic tanks, and thermal protection systems. Each of the technologies in these areas are discussed in this paper.

  3. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program : Bell Helicopter Textron accomplishments

    NASA Technical Reports Server (NTRS)

    Cronkhite, James D.

    1993-01-01

    Accurate vibration prediction for helicopter airframes is needed to 'fly from the drawing board' without costly development testing to solve vibration problems. The principal analytical tool for vibration prediction within the U.S. helicopter industry is the NASTRAN finite element analysis. Under the NASA DAMVIBS research program, Bell conducted NASTRAN modeling, ground vibration testing, and correlations of both metallic (AH-1G) and composite (ACAP) airframes. The objectives of the program were to assess NASTRAN airframe vibration correlations, to investigate contributors to poor agreement, and to improve modeling techniques. In the past, there has been low confidence in higher frequency vibration prediction for helicopters that have multibladed rotors (three or more blades) with predominant excitation frequencies typically above 15 Hz. Bell's findings under the DAMVIBS program, discussed in this paper, included the following: (1) accuracy of finite element models (FEM) for composite and metallic airframes generally were found to be comparable; (2) more detail is needed in the FEM to improve higher frequency prediction; (3) secondary structure not normally included in the FEM can provide significant stiffening; (4) damping can significantly affect phase response at higher frequencies; and (5) future work is needed in the areas of determination of rotor-induced vibratory loads and optimization.

  4. Rab35, acting through ACAP2 switching off Arf6, negatively regulates oligodendrocyte differentiation and myelination

    PubMed Central

    Miyamoto, Yuki; Yamamori, Natsuki; Torii, Tomohiro; Tanoue, Akito; Yamauchi, Junji

    2014-01-01

    Oligodendrocyte precursor cells differentiate to produce myelin sheaths that insulate axons to ensure fast propagation of action potentials. Many aspects of differentiation are regulated by multiple extracellular signals. However, their intracellular signalings remain elusive. We show that Rab35 and its effector, ACAP2, a GTPase-activating protein that switches off Arf6 activity, negatively regulate oligodendrocyte morphological differentiation. Knockdown of Rab35 or ACAP2 with their respective small interfering RNAs promotes differentiation. As differentiation initiates, the activities of Rab35 and ACAP2 are down-regulated. The activity of Arf6, in contrast, is up-regulated. Arf6 knockdown inhibits differentiation, indicating that Rab35 and ACAP2 negatively regulate differentiation by down-regulating Arf6. Importantly, as differentiation proceeds, the activity of cytohesin-2, a guanine nucleotide exchange factor that switches on Arf6 activity, is up-regulated. Pharmacological inhibition of cytohesin-2 inhibits differentiation, suggesting that cytohesin-2 promotes differentiation by activating Arf6. Furthermore, using oligodendrocyte-neuronal cocultures, we find that knockdown of Rab35 or ACAP2 promotes myelination, whereas inhibition of cytohesin-2 or knockdown of Arf6 inhibits myelination. Thus Rab35/ACAP2 and cytohesin-2 antagonistically control oligodendrocyte differentiation and myelination through Arf6 regulation, presenting a unique small GTPase on/off switching mechanism. PMID:24600047

  5. Integration of Feature Calibration and Alignment into ACAPS

    NASA Astrophysics Data System (ADS)

    Woods, B. K.; Nehrkorn, T.

    2011-12-01

    In support of the National Center for Atmospheric Research (NCAR) development of the Air Force Weather Agency (AFWA) Coupled Analysis and Prediction System (ACAPS), a data assimilation preprocessor was developed to displace model fields using Feature Calibration and Alignment (FCA; Hoffman et al., 1995). A Fotran90 API was written to apply FCA displacements to WRF input as a preprocessor for 4DVar. A modified version of the vortex relocation scheme of Hsiao et al. (2010) was applied to maintain dynamical balance. Unlike Hsiao et al. (2010), sea level pressure was displaced rather than surface pressure, and relative humidity was used in the displacement in lieu of water vapor mixing ratio. A time-lagged test was run using the Hurricane Katrina default WRF case. The 12-hour control forecast was used as pseudo-observations to displace the 6-hour control forecast forward along the hurricane's track. After completing an additional 18-hour integration (for a total of 24 hours), the hurricane maintained its forward displaced position. The modifications of Hsiao's algorithm allowed for the application of displacement across the entire model domain rather than only over flat areas and significantly reduced terrain-induced artifacts.

  6. Phosphorylation of the Bin, Amphiphysin, and RSV161/167 (BAR) domain of ACAP4 regulates membrane tubulation

    PubMed Central

    Zhao, Xuannv; Wang, Dongmei; Liu, Xing; Liu, Lifang; Song, Zhenwei; Zhu, Tongge; Adams, Gregory; Gao, Xinjiao; Tian, Ruijun; Huang, Yuejia; Chen, Runhua; Wang, Fengsong; Liu, Dong; Yu, Xue; Chen, Yong; Chen, Zhengjun; Teng, Maikun; Ding, Xia; Yao, Xuebiao

    2013-01-01

    ArfGAP With Coiled-Coil, Ankyrin Repeat And PH Domains 4 (ACAP4) is an ADP-ribosylation factor 6 (ARF6) GTPase-activating protein essential for EGF-elicited cell migration. However, how ACAP4 regulates membrane dynamics and curvature in response to EGF stimulation is unknown. Here, we show that phosphorylation of the N-terminal region of ACAP4, named the Bin, Amphiphysin, and RSV161/167 (BAR) domain, at Tyr34 is necessary for EGF-elicited membrane remodeling. Domain structure analysis demonstrates that the BAR domain regulates membrane curvature. EGF stimulation of cells causes phosphorylation of ACAP4 at Tyr34, which subsequently promotes ACAP4 homodimer curvature. The phospho-mimicking mutant of ACAP4 demonstrates lipid-binding activity and tubulation in vitro, and ARF6 enrichment at the membrane is associated with ruffles of EGF-stimulated cells. Expression of the phospho-mimicking ACAP4 mutant promotes ARF6-dependent cell migration. Thus, the results present a previously undefined mechanism by which EGF-elicited phosphorylation of the BAR domain controls ACAP4 molecular plasticity and plasma membrane dynamics during cell migration. PMID:23776207

  7. Integrated airframe propulsion control

    NASA Technical Reports Server (NTRS)

    Fennell, R. E.; Black, S. B.

    1982-01-01

    Perturbation equations which describe flight dynamics and engine operation about a given operating point are combined to form an integrated aircraft/propulsion system model. Included in the model are the dependence of aerodynamic coefficients upon atmospheric variables along with the dependence of engine variables upon flight condition and inlet performance. An off-design engine performance model is used to identify interaction parameters in the model. Inclusion of subsystem interaction effects introduces coupling between flight and propulsion variables. To analyze interaction effects on control, consideration is first given to control requirements for separate flight and engine models. For the separate airframe model, feedback control provides substantial improvement in short period damping. For the integrated system, feedback control compensates for the coupling present in the model and provides good overall system stability. However, this feedback control law involves many non-zero gains. Analysis of suboptimal control strategies indicates that performance of the closed loop integrated system can be maintained with a feedback matrix in which the number of non-zero gains is small relative to the number of components in the feedback matrix.

  8. ACAP-A/B are ArfGAP homologs in dictyostelium involved in sporulation but not in chemotaxis.

    PubMed

    Chen, Pei-Wen; Randazzo, Paul A; Parent, Carole A

    2010-01-07

    Arfs and Arf GTPase-activating proteins (ArfGAPs) are regulators of membrane trafficking and actin dynamics in mammalian cells. In this study, we identified a primordial Arf, ArfA, and two ArfGAPs (ACAP-A/B) containing BAR, PH, ArfGAP and Ankyrin repeat domains in the eukaryote Dictyostelium discoideum. In vitro, ArfA has similar nucleotide binding properties as mammalian Arfs and, with GTP bound, is a substrate for ACAP-A and B. We also investigated the physiological functions of ACAP-A/B by characterizing cells lacking both ACAP-A and B. Although ACAP-A/B knockout cells showed no defects in cell growth, migration or chemotaxis, they exhibited abnormal actin protrusions and approximately 50% reduction in spore yield. We conclude that while ACAP-A/B have a conserved biochemical mechanism and effect on actin organization, their role in migration is not conserved. The absence of an effect on Dictyostelium migration may be due to a specific requirement for ACAPs in mesenchymal migration, which is observed in epithelial cancer cells where most studies of mammalian ArfGAPs were performed.

  9. Airframe technology for aircraft energy efficiency. [economic factors

    NASA Technical Reports Server (NTRS)

    James, R. L., Jr.; Maddalon, D. V.

    1984-01-01

    The economic factors that resulted in the implementation of the aircraft energy efficiency program (ACEE) are reviewed and airframe technology elements including content, progress, applications, and future direction are discussed. The program includes the development of laminar flow systems, advanced aerodynamics, active controls, and composite structures.

  10. Optimal airframe synthesis for gust loads

    NASA Technical Reports Server (NTRS)

    Hajela, P.

    1986-01-01

    An optimization capability for sizing airframe structures that are subjected to a combination of deterministic and random flight loads was established. The random vibration environment introduces the need for selecting a statistical process that best describes the random loads and permits computation of the dynamic response parameters of interest. Furthermore, it requires a formulation of design constraints that would minimize the conservativeness in the design and retain computational viability. The random loads are treated as a stationary, homogeneous process with a Gaussian probability distribution. The formulation of the analysis problem, the structure of the optimization programming system and a representative numerical example are discussed.

  11. Fuel efficiency through new airframe technology

    NASA Technical Reports Server (NTRS)

    Leonard, R. W.

    1982-01-01

    In its Aircraft Energy Efficiency Program, NASA has expended approximately 200 million dollars toward development and application of advanced airframe technologies to United States's commercial transports. United States manufacturers have already been given a significant boost toward early application of advanced composite materials to control surface and empennage structures and toward selected applications of active controls and advanced aerodynamic concepts. In addition, significant progress in definition and development of innovative, but realistic systems for laminar flow control over the wings of future transports has already been made.

  12. Airframe Research and Technology for Hypersonic Airbreathing Vehicles

    NASA Technical Reports Server (NTRS)

    Glass, David E.; Merski, N. Ronald; Glass, Christopher E.

    2002-01-01

    The Hypersonics Investment Area (HIA) within NASA's Advanced Space Transportation Program (ASTP) has the responsibility to develop hypersonic airbreathing vehicles for access to space. The Airframe Research and Technology (AR and T) Project, as one of six projects in the HIA, will push the state-of-the-art in airframe and vehicle systems for low-cost, reliable, and safe space transportation. The individual technologies within the project are focused on advanced, breakthrough technologies in airframe and vehicle systems and cross-cutting activities that are the basis for improvements in these disciplines. Both low and medium technology readiness level (TRL) activities are being pursued. The key technical areas that will be addressed by the project include analysis and design tools, integrated vehicle health management (IVHM), composite (polymer, metal, and ceramic matrix) materials development, thermal/structural wall concepts, thermal protection systems, seals, leading edges, aerothermodynamics, and airframe/propulsion flowpath technology. Each of the technical areas or sub-projects within the Airframe R and T Project is described in this paper.

  13. Investigation on the use of optimization techniques for helicopter airframe vibrations design studies

    NASA Technical Reports Server (NTRS)

    Sreekanta Murthy, T.

    1992-01-01

    Results of the investigation of formal nonlinear programming-based numerical optimization techniques of helicopter airframe vibration reduction are summarized. The objective and constraint function and the sensitivity expressions used in the formulation of airframe vibration optimization problems are presented and discussed. Implementation of a new computational procedure based on MSC/NASTRAN and CONMIN in a computer program system called DYNOPT for optimizing airframes subject to strength, frequency, dynamic response, and dynamic stress constraints is described. An optimization methodology is proposed which is thought to provide a new way of applying formal optimization techniques during the various phases of the airframe design process. Numerical results obtained from the application of the DYNOPT optimization code to a helicopter airframe are discussed.

  14. Dictyostelium ACAP-A is an ArfGAP involved in cytokinesis, cell migration and actin cytoskeleton dynamics.

    PubMed

    Dias, Marco; Blanc, Cédric; Thazar-Poulot, Nelcy; Ben Larbi, Sabrina; Cosson, Pierre; Letourneur, François

    2013-02-01

    ACAPs and ASAPs are Arf-GTPase-activating proteins with BAR, PH, GAP and ankyrin repeat domains and are known to regulate vesicular traffic and actin cytoskeleton dynamics in mammalian cells. The amoeba Dictyostelium has only two proteins with this domain organization, instead of the six in human, enabling a more precise functional analysis. Genetic invalidation of acapA resulted in multinucleated cells with cytokinesis defects. Mutant acapA(-) cells were hardly motile and their multicellular development was significantly delayed. In addition, formation of filopodial protrusions was deficient in these cells. Conversely, re-expression of ACAP-A-GFP resulted in numerous and long filopodia-like protrusions. Mutagenesis studies showed that the ACAP-A actin remodeling function was dependent on its ability to activate its substrate, the small GTPase ArfA. Likewise, the expression of a constitutively active ArfA•GTP mutant in wild-type cells led to a significant reduction in filopodia length. Together, our data support a role for ACAP-A in the control of the actin cytoskeleton organization and dynamics through an ArfA-dependent mechanism.

  15. Robotic dry stripping of airframes - Phase II

    NASA Astrophysics Data System (ADS)

    Pauli, Robert A.; Wittenberg, Art M.

    1989-03-01

    This paper describes a program for the development of a dust-free closed-cycle robotic system for dry stripping of airframes, designed to insure dust-free work environment and reduce plastic-media loss, the contamination risk, and the media inventory requirement. Phase I of the program involved building a prototype of the proposed robotic arm and its dust enclosure to prove basic automation concepts, showing reasonable paint removal rate from a curved surface, and establishing that the process is dust-free and recovers plastic media in a closed-cycle fashion. This paper contains calculations on the effect of different blasting parameters in order to determine optimum values required for the completion of Phase I. Also presented is the progress achieved by the Phase II of the program, which is to prove the total concept by building the complete system and demonstrating its capability.

  16. Fuel Efficiencies Through Airframe Improvements

    NASA Technical Reports Server (NTRS)

    Bezos-O'Connor, Gaudy M.; Mangelsdorf, Mark F.; Maliska, Heather A.; Washburn, Anthony E.; Wahls, Richard A.

    2011-01-01

    The factors of continuing strong growth in air traffic volume, the vital role of the air transport system on the economy, and concerns about the environmental impact of aviation have added focus to the National Aeronautics Research Policy. To address these concerns in the context of the National Policy, NASA has set aggressive goals in noise reduction, emissions, and energy consumption. With respect to the goal of reducing energy consumption in the fleet, the development of promising airframe technologies is required to realize the significant improvements that are desired. Furthermore, the combination of advances in materials and structures with aerodynamic technologies may lead to a paradigm shift in terms of potential configurations for the future. Some of these promising airframe technologies targeted at improved efficiency are highlighted.

  17. A formulation of rotor-airframe coupling for design analysis of vibrations of helicopter airframes

    NASA Technical Reports Server (NTRS)

    Kvaternik, R. G.; Walton, W. C., Jr.

    1982-01-01

    A linear formulation of rotor airframe coupling intended for vibration analysis in airframe structural design is presented. The airframe is represented by a finite element analysis model; the rotor is represented by a general set of linear differential equations with periodic coefficients; and the connections between the rotor and airframe are specified through general linear equations of constraint. Coupling equations are applied to the rotor and airframe equations to produce one set of linear differential equations governing vibrations of the combined rotor airframe system. These equations are solved by the harmonic balance method for the system steady state vibrations. A feature of the solution process is the representation of the airframe in terms of forced responses calculated at the rotor harmonics of interest. A method based on matrix partitioning is worked out for quick recalculations of vibrations in design studies when only relatively few airframe members are varied. All relations are presented in forms suitable for direct computer implementation.

  18. Airframe noise: A design and operating problem

    NASA Technical Reports Server (NTRS)

    Hardin, J. C.

    1976-01-01

    A critical assessment of the state of the art in airframe noise is presented. Full-scale data on the intensity, spectra, and directivity of this noise source are evaluated in light of the comprehensive theory developed by Ffowcs Williams and Hawkings. Vibration of panels on the aircraft is identified as a possible additional source of airframe noise. The present understanding and methods for prediction of other component sources - airfoils, struts, and cavities - are discussed. Operating problems associated with airframe noise as well as potential design methods for airframe noise reduction are identified.

  19. IMPAC: An Integrated Methodology for Propulsion and Airframe Control

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Ouzts, Peter J.; Lorenzo, Carl F.; Mattern, Duane L.

    1991-01-01

    The National Aeronautics and Space Administration is actively involved in the development of enabling technologies that will lead towards aircraft with new/enhanced maneuver capabilities such as Short Take-Off Vertical Landing (STOVL) and high angle of attack performance. Because of the high degree of dynamic coupling between the airframe and propulsion systems of these types of aircraft, one key technology is the integration of the flight and propulsion control. The NASA Lewis Research Center approach to developing Integrated Flight Propulsion Control (IFPC) technologies is an in-house research program referred to as IMPAC (Integrated Methodology for Propulsion and Airframe Control). The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. Based on some preliminary control design studies that included evaluation of the existing methodologies, the IFPC design methodology that is emerging at the Lewis Research Center consists of considering the airframe and propulsion system as one integrated system for an initial centralized controller design and then partitioning the centralized controller into separate airframe and propulsion system subcontrollers to ease implementation and to set meaningful design requirements for detailed subsystem control design and evaluation. An overview of IMPAC is provided and detailed discussion of the various important design and evaluation steps in the methodology are included.

  20. Crashworthy airframe design concepts: Fabrication and testing

    NASA Technical Reports Server (NTRS)

    Cronkhite, J. D.; Berry, V. L.

    1982-01-01

    Crashworthy floor concepts applicable to general aviation aircraft metal airframe structures were investigated. Initially several energy absorbing lower fuselage structure concepts were evaluated. Full scale floor sections representative of a twin engine, general aviation airplane lower fuselage structure were designed and fabricated. The floors featured an upper high strength platform with an energy absorbing, crushable structure underneath. Eighteen floors were fabricated that incorporated five different crushable subfloor concepts. The floors were then evaluated through static and dynamic testing. Computer programs NASTRAN and KRASH were used for the static and dynamic analysis of the floor section designs. Two twin engine airplane fuselages were modified to incorporate the most promising crashworthy floor sections for test evaluation.

  1. Correlation of AH-1G airframe test data with a NASTRAN mathematical model

    NASA Technical Reports Server (NTRS)

    Cronkhite, J. D.; Berry, V. L.

    1976-01-01

    Test data was provided for evaluating a mathematical vibration model of the Bell AH-1G helicopter airframe. The math model was developed and analyzed using the NASTRAN structural analysis computer program. Data from static and dynamic tests were used for comparison with the math model. Static tests of the fuselage and tailboom were conducted to verify the stiffness representation of the NASTRAN model. Dynamic test data were obtained from shake tests of the airframe and were used to evaluate the NASTRAN model for representing the low frequency (below 30 Hz) vibration response of the airframe.

  2. The Arf6 GTPase-activating Proteins ARAP2 and ACAP1 Define Distinct Endosomal Compartments That Regulate Integrin α5β1 Traffic*

    PubMed Central

    Chen, Pei-Wen; Luo, Ruibai; Jian, Xiaoying; Randazzo, Paul A.

    2014-01-01

    Arf6 and the Arf6 GTPase-activating protein (GAP) ACAP1 are established regulators of integrin traffic important to cell adhesion and migration. However, the function of Arf6 with ACAP1 cannot explain the range of Arf6 effects on integrin-based structures. We propose that Arf6 has different functions determined, in part, by the associated Arf GAP. We tested this idea by comparing the Arf6 GAPs ARAP2 and ACAP1. We found that ARAP2 and ACAP1 had opposing effects on apparent integrin β1 internalization. ARAP2 knockdown slowed, whereas ACAP1 knockdown accelerated, integrin β1 internalization. Integrin β1 association with adaptor protein containing a pleckstrin homology (PH) domain, phosphotyrosine-binding (PTB) domain, and leucine zipper motif (APPL)-positive endosomes and EEA1-positive endosomes was affected by ARAP2 knockdown and depended on ARAP2 GAP activity. ARAP2 formed a complex with APPL1 and colocalized with Arf6 and APPL in a compartment distinct from the Arf6/ACAP1 tubular recycling endosome. In addition, although ACAP1 and ARAP2 each colocalized with Arf6, they did not colocalize with each other and had opposing effects on focal adhesions (FAs). ARAP2 overexpression promoted large FAs, but ACAP1 overexpression reduced FAs. Taken together, the data support a model in which Arf6 has at least two sites of opposing action defined by distinct Arf6 GAPs. PMID:25225293

  3. ACAP4 Protein Cooperates with Grb2 Protein to Orchestrate Epidermal Growth Factor-stimulated Integrin β1 Recycling in Cell Migration*

    PubMed Central

    Yu, Xue; Wang, Fengsong; Liu, Hongsheng; Adams, Gregory; Aikhionbare, Felix; Liu, Dong; Cao, Xinwang; Fan, Libin; Hu, Guohong; Chen, Yong; Frost, Andra; Partridge, Edward; Ding, Xia; Yao, Xuebiao

    2011-01-01

    ARF6 GTPase is an important regulator of membrane trafficking and actin-based cytoskeleton dynamics active at the leading edge of migrating cells. The integrin family heterodimeric transmembrane proteins serve as major receptors for extracellular matrix proteins, which play essential roles in cell adhesion and migration. Our recent proteomic analyses of ARF6 effectors have identified a novel ARF6 GTPase-activating protein, ACAP4, essential for EGF-induced cell migration. However, molecular mechanisms underlying ACAP4-mediated cell migration have remained elusive. Here, we show that ACAP4 regulates integrin β1 dynamics during EGF-stimulated cell migration by interaction with Grb2. Our biochemical study shows that EGF stimulation induces phosphorylation of tyrosine 733, which enables ACAP4 to bind Grb2. This interaction of ACAP4 with Grb2 regulates integrin β1 recycling to the plasma membrane. Importantly, knockdown of ACAP4 by siRNA or overexpression of ACAP4 decreased recycling of integrin β1 to the plasma membrane and reduced integrin-mediated cell migration. Taken together, these results suggest a novel function for ACAP4 in the regulation of cell migration through controlling integrin β1 dynamics. PMID:22027826

  4. The Airframe Noise Reduction Challenge

    NASA Technical Reports Server (NTRS)

    Lockhard, David P.; Lilley, Geoffrey M.

    2004-01-01

    The NASA goal of reducing external aircraft noise by 10 dB in the near-term presents the acoustics community with an enormous challenge. This report identifies technologies with the greatest potential to reduce airframe noise. Acoustic and aerodynamic effects will be discussed, along with the likelihood of industry accepting and implementing the different technologies. We investigate the lower bound, defined as noise generated by an aircraft modified with a virtual retrofit capable of eliminating all noise associated with the high lift system and landing gear. However, the airframe noise of an aircraft in this 'clean' configuration would only be about 8 dB quieter on approach than current civil transports. To achieve the NASA goal of 10 dB noise reduction will require that additional noise sources be addressed. Research shows that energy in the turbulent boundary layer of a wing is scattered as it crosses trailing edge. Noise generated by scattering is the dominant noise mechanism on an aircraft flying in the clean configuration. Eliminating scattering would require changes to much of the aircraft, and practical reduction devices have yet to receive serious attention. Evidence suggests that to meet NASA goals in civil aviation noise reduction, we need to employ emerging technologies and improve landing procedures; modified landing patterns and zoning restrictions could help alleviate aircraft noise in communities close to airports.

  5. Landing approach airframe noise measurements and analysis

    NASA Technical Reports Server (NTRS)

    Lasagna, P. L.; Mackall, K. G.; Burcham, F. W., Jr.; Putnam, T. W.

    1980-01-01

    Flyover measurements of the airframe noise produced by the AeroCommander, JetStar, CV-990, and B-747 airplanes are presented for various landing approach configurations. Empirical and semiempirical techniques are presented to correlate the measured airframe noise with airplane design and aerodynamic parameters. Airframe noise for the jet-powered airplanes in the clean configuration (flaps and gear retracted) was found to be adequately represented by a function of airplane weight and the fifth power of airspeed. Results show the airframe noise for all four aircraft in the landing configuration (flaps extended and gear down) also varied with the fifth power of airspeed, but this noise level could not be represented by the addition of a constant to the equation for clean-configuration airframe noise.

  6. Airframe Noise Reduction Studies and Clean-Airframe Noise Investigation

    NASA Technical Reports Server (NTRS)

    Fink, M. R.; Bailey, D. A.

    1980-01-01

    Acoustic wind tunnel tests were conducted of a wing model with modified leading edge slat and trailing edge flap. The modifications were intended to reduce the surface pressure response to convected turbulence and thereby reduce the airframe noise without changing the lift at constant incidence. Tests were conducted at 70.7 and 100 m/sec airspeeds, with Reynolds numbers 1.5 x 10 to the 6th power and 2.1 x 10 to the 6th power. Considerable reduction of noise radiation from the side edges of a 40 deflection single slotted flap was achieved by modification to the side edge regions or the leading edge region of the flap panel. Total far field noise was reduced 2 to 3 dB over several octaves of frequency. When these panels were installed as the aft panel of a 40 deg deflection double slotted flap, 2 dB noise reduction was achieved.

  7. An integrated computer procedure for sizing composite airframe structures

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, J.

    1979-01-01

    A computerized algorithm to generate cross-sectional dimensions and fiber orientations for composite airframe structures is described, and its application in a wing structural synthesis is established. The algorithm unifies computations of aeroelastic loads, stresses, and deflections, as well as optimal structural sizing and fiber orientations in an open-ended system of integrated computer programs. A finite-element analysis and a mathematical-optimization technique are discussed.

  8. Propulsion airframe integration session overview and review of Lewis PAI efforts

    NASA Technical Reports Server (NTRS)

    Batterton, Peter G.

    1992-01-01

    Propulsion/Airframe Integration (PAI) is a key issue for the High Speed Civil Transport. The aircraft performance, economics, and environmental acceptability can be adversely affected if the integration of the propulsion system and the airframe is not addressed properly or in a timely manner. Some of the goals are listed in this figure. In particular, these goals are highly influenced by how successfully the propulsion system and airframe are integrated. These goals were grouped by the 'Aero' and 'Propulsion' categories to suggest which group of technologists will likely be addressing them. In terms of the NASA High Speed Research Program, the ultimate objective for propulsion/airframe integration is to demonstrate the technologies for achievement of these goals on a 'single' integrated configuration.

  9. Status of ERA Airframe Technology Demonstrators

    NASA Technical Reports Server (NTRS)

    Davis, Pamela; Jegley, Dawn; Rigney, Tom

    2015-01-01

    NASA has created the Environmentally Responsible Aviation (ERA) Project to explore and document the feasibility, benefits and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community noise. The Airframe Technology subproject contains two elements. Under the Damage Arresting Composite Demonstration an advanced material system is being explored which will lead to lighter airframes that are more structural efficient than the composites used in aircraft today. Under the Adaptive Compliant Trailing Edge Flight Experiment a new concept of a flexible wing trailing edge is being evaluated which will reduce weight and improve aerodynamic performance. This presentation will describe the development these two airframe technologies.

  10. Airframe-Jet Engine Integration Noise

    NASA Technical Reports Server (NTRS)

    Tam, Christopher; Antcliff, Richard R. (Technical Monitor)

    2003-01-01

    It has been found experimentally that the noise radiated by a jet mounted under the wing of an aircraft exceeds that of the same jet in a stand-alone environment. The increase in noise is referred to as jet engine airframe integration noise. The objectives of the present investigation are, (1) To obtain a better understanding of the physical mechanisms responsible for jet engine airframe integration noise or installation noise. (2) To develop a prediction model for jet engine airframe integration noise. It is known that jet mixing noise consists of two principal components. They are the noise from the large turbulence structures of the jet flow and the noise from the fine scale turbulence. In this investigation, only the effect of jet engine airframe interaction on the fine scale turbulence noise of a jet is studied. The fine scale turbulence noise is the dominant noise component in the sideline direction. Thus we limit out consideration primarily to the sideline.

  11. Impact Testing and Simulation of Composite Airframe Structures

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Littell, Justin D.; Horta, Lucas G.; Annett, Martin S.; Fasanella, Edwin L.; Seal, Michael D., II

    2014-01-01

    Dynamic tests were performed at NASA Langley Research Center on composite airframe structural components of increasing complexity to evaluate their energy absorption behavior when subjected to impact loading. A second objective was to assess the capabilities of predicting the dynamic response of composite airframe structures, including damage initiation and progression, using a state-of-the-art nonlinear, explicit transient dynamic finite element code, LS-DYNA. The test specimens were extracted from a previously tested composite prototype fuselage section developed and manufactured by Sikorsky Aircraft Corporation under the US Army's Survivable Affordable Repairable Airframe Program (SARAP). Laminate characterization testing was conducted in tension and compression. In addition, dynamic impact tests were performed on several components, including I-beams, T-sections, and cruciform sections. Finally, tests were conducted on two full-scale components including a subfloor section and a framed fuselage section. These tests included a modal vibration and longitudinal impact test of the subfloor section and a quasi-static, modal vibration, and vertical drop test of the framed fuselage section. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from instrumentation such as accelerometers and strain gages and from full-field photogrammetry.

  12. Fundamental Investigations of Airframe Noise

    NASA Technical Reports Server (NTRS)

    Macaraeg, M. G.

    2004-01-01

    An extensive numerical and experimental study of airframe noise mechanisms associated with a subsonic high-lift system has been performed at NASA Langley Research Center (LaRC). Investigations involving both steady and unsteady computations and experiments on a small-scale, part-span flap model are presented. Both surface (steady and unsteady pressure measurements, hot films, oil flows, pressure sensitive paint) and off surface (5 hole-probe, particle-imaged velocimetry, laser velocimetry, laser light sheet measurements) were taken in the LaRC Quiet Flow Facility (QFF) and several hard-wall tunnels up to flight Reynolds number. Successful microphone array measurements were also taken providing both acoustic source maps on the model, and quantitative spectra. Critical directivity measurements were obtained in the QFF. NASA Langley unstructured and structured Reynolds- Averaged Navier-Stokes codes modeled the flap geometries excellent comparisons with surface and offsurface experimental data were obtained. Subsequently, these meanflow calculations were utilized in both linear stability and direct numerical simulations of the flap-edge flow field to calculate unsteady surface pressures and farfield acoustic spectra. Accurate calculations were critical in obtaining not only noise source characteristics, but shear layer correction data as well. Techniques utilized in these investigations as well as brief overviews of results will be given.

  13. Should we attempt global (inlet engine airframe) control design?

    NASA Technical Reports Server (NTRS)

    Carlin, C. M.

    1980-01-01

    The feasibility of multivariable design of the entire airplane control system is briefly addressed. An intermediate step in that direction is to design a control for an inlet engine augmentor system by using multivariable techniques. The supersonic cruise large scale inlet research program is described which will provide an opportunity to develop, integrate, and wind tunnel test a control for a mixed compression inlet and variable cycle engine. The integrated propulsion airframe control program is also discussed which will introduce the problem of implementing MVC within a distributed processing avionics architecture, requiring real time decomposition of the global design into independent modules in response to hardware communication failures.

  14. Assessment of temporal bias in longitudinal measurements of carotid intimal-medial thickness in the Asymptomatic Carotid Artery Progression Study (ACAPS). ACAPS Research Group.

    PubMed

    Riley, W A; Craven, T; Romont, A; Furberg, C D

    1996-01-01

    A randomly selected subset of 100 pairs of baseline and 36-month follow-up carotid B-mode ultrasound examinations from the 919 patients participating in the Asymptomatic Carotid Artery Progression Study (ACAPS) were subjected to a blinded rereading at the conclusion of the trial to assess temporal bias in the measurement of carotid artery intimal-medial thickness (IMT). The original measurements of the primary outcome variable and five secondary outcome variables at baseline and 36 months, respectively, and the 3-year change in each of these variables, were compared with those obtained from the rereadings. For the primary outcome variable, the mean value of 12 IMT measurements obtained from predefined carotid segments, the mean difference (original-rereading) and the 95% confidence interval which resulted from the rereadings were -0.005 (-0.033, 0.023) mm at baseline and -0.009 (-0.031, 0.013) mm at 36 months. The difference in the 3-year change was -0.004 (-0.038, 0.028) mm. The 95% confidence interval for the mean difference between the rereadings and the original readings for the baseline and the 36-month follow-up examinations included zero for all of the six outcome variables as was also the case for the 3-year change in each variable. The magnitude of the mean differences for these 18 variables ranged from 0.004 to 0.034 mm. Intraclass correlation coefficients between the original readings and rereadings ranged from 0.56 to 0.87 with the 3-year changes in outcome variables tending to have lower correlations and the 36-month examinations higher correlations. The carotid IMT measurement process, when combined with uniform reader training, certification and monitoring of reading performance throughout the course of the study, can avoid the temporal bias observed in other studies.

  15. Calculation of rotor impedance for use in design analysis of helicopter airframe vibrations

    NASA Technical Reports Server (NTRS)

    Nygren, Kip P.

    1990-01-01

    Excessive vibration is one of the most prevalent technical obstacles encountered in the development of new rotorcraft. The inability to predict these vibrations is primarily due to deficiencies in analysis and simulation tools. The Langley Rotorcraft Structural Dynamics Program was instituted in 1984 to meet long term industry needs in the area of rotorcraft vibration prediction. As a part of the Langley program, this research endeavors to develop an efficient means of coupling the rotor to the airframe for preliminary design analysis of helicopter airframe vibrations. The main effort was to modify the existing computer program for modeling the dynamic and aerodynamic behavior of rotorcraft called DYSCO (DYnamic System COupler) to calculate the rotor impedance. DYSCO was recently developed for the U.S. Army and has proven to be adaptable for the inclusion of new solution methods. The solution procedure developed to use DYSCO for the calculation of rotor impedance is presented. Verification of the procedure by comparison with a known solution for a simple wind turbine model is about 75 percent completed, and initial results are encouraging. After the wind turbine impedance is confirmed, the verification effort will continue by comparison to solutions of a more sophisticated rotorcraft model. Future work includes determination of the sensitivity of the rotorcraft airframe vibrations to helicopter flight conditions and rotor modeling assumptions. When completed, this research will ascertain the feasibility and efficiency of the impedance matching method of rotor-airframe coupling for use in the analysis of airframe vibrations during the preliminary rotorcraft design process.

  16. Preliminary Analysis of Acoustic Measurements from the NASA-Gulfstream Airframe Noise Flight Test

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Lockhard, David D.; Humphreys, Willliam M.; Choudhari, Meelan M.; Van De Ven, Thomas

    2008-01-01

    The NASA-Gulfstream joint Airframe Noise Flight Test program was conducted at the NASA Wallops Flight Facility during October, 2006. The primary objective of the AFN flight test was to acquire baseline airframe noise data on a regional jet class of transport in order to determine noise source strengths and distributions for model validation. To accomplish this task, two measuring systems were used: a ground-based microphone array and individual microphones. Acoustic data for a Gulfstream G550 aircraft were acquired over the course of ten days. Over twenty-four test conditions were flown. The test matrix was designed to provide an acoustic characterization of both the full aircraft and individual airframe components and included cruise to landing configurations. Noise sources were isolated by selectively deploying individual components (flaps, main landing gear, nose gear, spoilers, etc.) and altering the airspeed, glide path, and engine settings. The AFN flight test program confirmed that the airframe is a major contributor to the noise from regional jets during landing operations. Sound pressure levels from the individual microphones on the ground revealed the flap system to be the dominant airframe noise source for the G550 aircraft. The corresponding array beamform maps showed that most of the radiated sound from the flaps originates from the side edges. Using velocity to the sixth power and Strouhal scaling of the sound pressure spectra obtained at different speeds failed to collapse the data into a single spectrum. The best data collapse was obtained when the frequencies were left unscaled.

  17. A PH domain in ACAP1 possesses key features of the BAR domain in promoting membrane curvature

    PubMed Central

    Pang, Xiaoyun; Fan, Jun; Zhang, Yan; Zhang, Kai; Gao, Bingquan; Ma, Jun; Li, Jian; Deng, Yuchen; Zhou, Qiangjun; Egelman, Edward H.; Hsu, Victor W.; Sun, Fei

    2014-01-01

    SUMMARY The BAR (Bin-Amphiphysin-Rvs) domain undergoes dimerization to produce a curved protein structure, which superimposes onto membrane through electrostatic interactions to sense and impart membrane curvature. In some cases, a BAR domain also possesses an amphipathic helix that inserts into the membrane to induce curvature. ACAP1 (Arfgap with Coil coil, Ankyrin repeat and PH domain protein 1) contains a BAR domain. Here, we show that this BAR domain can neither bind membrane nor impart curvature, but instead, requires a neighboring PH (Pleckstrin Homology) domain to achieve these functions. Specific residues within the PH domain are responsible for both membrane binding and curvature generation. The BAR domain adjacent to the PH domain instead interacts with the BAR domains of neighboring ACAP1 proteins to enable clustering at the membrane. Thus, we have uncovered the molecular basis for an unexpected and unconventional collaboration between PH and BAR domains in membrane bending. PMID:25284369

  18. Molecular Details of the PH Domain of ACAP1(BAR-PH) Protein Binding to PIP-Containing Membrane.

    PubMed

    Chan, Kevin Chun; Lu, Lanyuan; Sun, Fei; Fan, Jun

    2017-02-03

    ACAP1 proteins were previously reported to specifically bind PIP2-containing cell membranes and form well-structured protein lattices in order to conduct membrane tubulation. We carried out molecular dynamics simulations to characterize orientation of the PH domains with respect to the BAR domains inside the protein dimer. Followed by molecular dynamics simulations, we present a comprehensive orientation analysis of PH domain under different states including unbound and bound with lipids. We have examined two binding pockets on the PH domain and present PMF profiles of the two pockets to account for their preference to PIP2 lipids. Combining orientation analysis and studies of binding pockets, our simulations results reveal valuable molecular basis for protein-lipid interactions of ACAP1 proteins during membrane remodeling process.

  19. Advanced subsonic transport approach noise: The relative contribution of airframe noise

    NASA Technical Reports Server (NTRS)

    Willshire, William L., Jr.; Garber, Donald P.

    1992-01-01

    With current engine technology, airframe noise is a contributing source for large commercial aircraft on approach, but not the major contributor. With the promise of much quieter jet engines with the planned new generation of high-by-pass turbofan engines, airframe noise has become a topic of interest in the advanced subsonic transport research program. The objective of this paper is to assess the contribution of airframe noise relative to the other aircraft noise sources on approach. The assessment will be made for a current technology large commercial transport aircraft and for an envisioned advanced technology aircraft. NASA's Aircraft Noise Prediction Program (ANOPP) will be used to make total aircraft noise predictions for these two aircraft types. Predicted noise levels and areas of noise contours will be used to determine the relative importance of the contributing approach noise sources. The actual set-up decks used to make the ANOPP runs for the two aircraft types are included in appendixes.

  20. Damage Tolerance: Assessment Handbook. Volume 2: Airframe Damage Tolerance Evaluation

    DTIC Science & Technology

    1993-10-01

    Airframe Damage Tolerance Evaluation NJ 084u5 DTIC FLE 15 1994 Research and Special Programs Administration John A. Volpe National Transportation Systems...permission of John Wiley and Sons, New York, N.Y.] (4-5] CORRODED END Magnes;um Magnesium alloys Zinc Galvanized steel or galvanized wrought iron Aluminum...Reprinted from M M. Ratwani and D.P. Wilhem , iDeelopment andEvaluation of Methods of Plane Strain Fractuire Analysis, Northrop Corporation, AFFDL-TR-73-42

  1. 14 CFR 65.85 - Airframe rating; additional privileges.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.85 Airframe rating; additional privileges. (a) Except as provided in paragraph (b) of this section, a certificated mechanic with...) A certificated mechanic with an airframe rating can approve and return to service an airframe,...

  2. 14 CFR 65.85 - Airframe rating; additional privileges.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.85 Airframe rating; additional privileges. (a) Except as provided in paragraph (b) of this section, a certificated mechanic with...) A certificated mechanic with an airframe rating can approve and return to service an airframe,...

  3. 14 CFR 65.85 - Airframe rating; additional privileges.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.85 Airframe rating; additional privileges. (a) Except as provided in paragraph (b) of this section, a certificated mechanic with...) A certificated mechanic with an airframe rating can approve and return to service an airframe,...

  4. 14 CFR 65.85 - Airframe rating; additional privileges.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.85 Airframe rating; additional privileges. (a) Except as provided in paragraph (b) of this section, a certificated mechanic with...) A certificated mechanic with an airframe rating can approve and return to service an airframe,...

  5. 14 CFR 65.85 - Airframe rating; additional privileges.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.85 Airframe rating; additional privileges. (a) Except as provided in paragraph (b) of this section, a certificated mechanic with...) A certificated mechanic with an airframe rating can approve and return to service an airframe,...

  6. Plan, formulate, discuss and correlate a NASTRAN finite element vibrations model of the Boeing Model 360 helicopter airframe

    NASA Technical Reports Server (NTRS)

    Gabel, R.; Lang, P. F.; Smith, L. A.; Reed, D. A.

    1989-01-01

    Boeing Helicopter, together with other United States helicopter manufacturers, participated in a finite element applications program to emplace in the United States a superior capability to utilize finite element analysis models in support of helicopter airframe design. The activities relating to planning and creating a finite element vibrations model of the Boeing Model 36-0 composite airframe are summarized, along with the subsequent analytical correlation with ground shake test data.

  7. Cost Functions for Airframe Production Programs.

    DTIC Science & Technology

    1982-07-01

    65 IS OBSOLETE SECURITY CLASSIFICATION OF THIS PAGE (When Dae Entered) S(CURITY CLASSIFICATION OF THIS PA ( E (Wen Data £ntered) 20. Cont’d. The...become available. An overview of the work accomplished on this contract is described next. E . WORK ACCOMPLISHED The work on thi.s contract was dividLI...analysis. These analyses are reported in section E of this chapter. The chapter is concluded with a discussion of the four effects which these analyses

  8. Structural Qualification of Composite Airframes

    NASA Technical Reports Server (NTRS)

    Kedward, Keith T.; McCarty, John E.

    1997-01-01

    The development of fundamental approaches for predicting failure and elongation characteristics of fibrous composites are summarized in this document. The research described includes a statistical formulation for individual fiber breakage and fragmentation and clustered fiber breakage, termed macrodefects wherein the aligned composite may represent a structural component such as a reinforcing bar element, a rebar. Experimental work conducted in support of the future exploitation of aligned composite rebar elements is also described. This work discusses the experimental challenges associated with rebar tensile test evaluation and describes initial numerical analyses performed in support of the experimental program.

  9. Combat Maintenance Concepts and Repair Techniques for Helicopter Airframe Structures

    DTIC Science & Technology

    1981-01-01

    helicopter airframe and to de- velop concepts for the assessment and repair of airframe combat damage. A computer model was developed to generate...random simulated hallistic strikes on the Black Hawk helicopter airframe. Random shotlines were generated with the model , and cases involving damage...Distribution of Ballistic Hits on Helicopters from Southeast Asia Combat Experience 23 Shotline Simulation Model 24 Conventions for Azimuth and

  10. Optimal actuator placement and active structure design for control of helicopter airframe vibrations

    NASA Astrophysics Data System (ADS)

    Heverly, David Ellsworth, II

    A comprehensive research program on active control of rotorcraft airframe vibration is detailed in this thesis. A systematic design methodology, to realize an active vibration control system, is proposed and studied. The methodology is a four-part design cycle and relies heavily on numerical computation, modeling, and analysis. The various analytical tools, models, and processes required to execute the methodology are described. Two dynamic models of the helicopter airframe and an optimization procedure for actuator placement are utilized within the methodology. The optimization procedure simultaneously determines the type of actuation, the locations to apply actuation, and the corresponding active control actions. A feasibility study is conducted to examine the effectiveness of helicopter vibration control by distributing actuators at optimal locations within the airframe, rather than confining actuation to a centralized region. Results indicate that distributed actuation is capable of greater vibration suppression and requires less control effort than a centralized actuation configuration. An analytical and experimental investigation is conducted on a scaled model of a helicopter tailboom. The scaled tailboom model is used to study the actuation design and realization issues associated with integrating dual-point actuation into a semi-monocoque airframe structure. A piezoelectric stack actuator configuration is designed and installed within the tailboom model. Experimental tests indicate the stack actuator configuration is able to produce a bending moment within the structure to suppress vibration without causing excessive localized stress in the structure.

  11. Aviation Maintenance Technology. Airframe. A201. Airframe Structures and Non-Metallic Structural Repairs. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This teacher's guide is designed to aid teachers in leading students through a module on airframe structures and nonmetallic structural repairs. The module contains four units that cover the following topics: (1) identifying aerodynamic and construction characteristics of aircraft structures; (2) inspecting wooden structures; (3) inspecting and…

  12. Airframe Noise Prediction by Acoustic Analogy: Revisited

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Casper, Jay H.; Tinetti, A.; Dunn, M. H.

    2006-01-01

    The present work follows a recent survey of airframe noise prediction methodologies. In that survey, Lighthill s acoustic analogy was identified as the most prominent analytical basis for current approaches to airframe noise research. Within this approach, a problem is typically modeled with the Ffowcs Williams and Hawkings (FW-H) equation, for which a geometry-independent solution is obtained by means of the use of the free-space Green function (FSGF). Nonetheless, the aeroacoustic literature would suggest some interest in the use of tailored or exact Green s function (EGF) for aerodynamic noise problems involving solid boundaries, in particular, for trailing edge (TE) noise. A study of possible applications of EGF for prediction of broadband noise from turbulent flow over an airfoil surface and the TE is, therefore, the primary topic of the present work. Typically, the applications of EGF in the literature have been limited to TE noise prediction at low Mach numbers assuming that the normal derivative of the pressure vanishes on the airfoil surface. To extend the application of EGF to higher Mach numbers, the uniqueness of the solution of the wave equation when either the Dirichlet or the Neumann boundary condition (BC) is specified on a deformable surface in motion. The solution of Lighthill s equation with either the Dirichlet or the Neumann BC is given for such a surface using EGFs. These solutions involve both surface and volume integrals just like the solution of FW-H equation using FSGF. Insight drawn from this analysis is evoked to discuss the potential application of EGF to broadband noise prediction. It appears that the use of a EGF offers distinct advantages for predicting TE noise of an airfoil when the normal pressure gradient vanishes on the airfoil surface. It is argued that such an approach may also apply to an airfoil in motion. However, for the prediction of broadband noise not directly associated with a trailing edge, the use of EGF does not

  13. Advanced design concepts for shuttle airframe structure

    NASA Technical Reports Server (NTRS)

    Card, M. F.; Davis, J. G., Jr.; Shideler, J. L.

    1972-01-01

    The development of weight-saving advanced design concepts for shuttle airframe structure is presented. Design concepts under investigation employ selective composite reinforcement and/or efficient geometric arrangements. An effort to develop metallic panel designs which exploit the relaxation of smooth external-surface requirements for skin structure is reviewed. Available highlights from research and development studies which investigate the application of composite reinforcement to the design of two types of fuselage panels, a shear web, a large fuselage frame, and a landing-gear-door assembly are presented. Preliminary results from these studies suggest weight savings of 25 percent can be obtained.

  14. SUPERSONIC TRANSPORT DEVELOPMENT AND PRODUCTION. VOLUME I. COST ANALYSIS PROGRAM.

    DTIC Science & Technology

    SUPERSONIC AIRCRAFT, *COSTS), (*AIRCRAFT INDUSTRY, INDUSTRIAL PRODUCTION ), MANAGEMENT ENGINEERING, AIRFRAMES, ECONOMICS, COMPUTER PROGRAMS, STATISTICAL ANALYSIS, MONEY, AIRCRAFT ENGINES, FEASIBILITY STUDIES

  15. Geo-Spatial Browse and Distribution of NSF-OPP's Antarctic Ice and Climate Data via the Web: Antarctic Cryosphere Access Portal (A-CAP)

    NASA Astrophysics Data System (ADS)

    Bauer, R.; Scambos, T.; Haran, T.; Maurer, J.; Bohlander, J.

    2008-12-01

    A prototype of the Antarctic Cryosphere Access Portal (A-CAP) has been released for public use. Developed at the National Snow and Ice Data Center (NSIDC) Antarctic Glaciological Data Center (AGDC), A-CAP aims to be a geo-visualization and data download tool for AGDC data and other Antarctic-wide parameters, including glaciology, ice core data, snow accumulation, satellite imagery, digital elevation models (DEMs), sea ice concentration, and many other cryosphere-related scientific measurements. The user can zoom in to a specific region as well as overlay coastlines, placenames, latitude/longitude, and other geographic information. In addition to providing an interactive Web interface, customizable A-CAP map images and source data are also accessible via specific Uniform Resource Locator strings (URLs) to a standard suite of Open Geospatial Consortium (OGC) services: Web Map Service (WMS), Web Feature Service (WFS), and Web Coverage Service (WCS). The international specifications of these services provide an interoperable framework for sharing maps and geospatial data over the Internet, allowing A-CAP products to be easily exchanged with other data centers worldwide and enabling remote access for users through OGC-compliant software applications such as ArcGIS, Google Earth, ENVI, and many others. A-CAP is built on MapServer, an Open Source development environment for building spatially-enabled Internet applications. MapServer uses data sets that have been formatted as GeoTIFF or Shapefile to allow rapid sub-setting and over-the-Web presentation of large geospatial data files, and has no requirement for a user-installed client software package (besides a Web browser).

  16. Simulating the Impact Response of Composite Airframe Components

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.

    2014-01-01

    In 2010, NASA Langley Research Center obtained residual hardware from the US Army's Survivable Affordable Repairable Airframe Program (SARAP). The hardware consisted of a composite fuselage section that was representative of the center section of a Black Hawk helicopter. The section was fabricated by Sikorsky Aircraft Corporation and designated the Test Validation Article (TVA). The TVA was subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead mass items, such as the rotor transmission, into the fuselage cabin. As a result of the 2008 test, damage to the hardware was limited primarily to the roof. Consequently, when the post-test article was obtained in 2010, the roof area was removed and the remaining structure was cut into six different types of test specimens including: (1) tension and compression coupons for material property characterization, (2) I-beam sections, (3) T-sections, (4) cruciform sections, (5) a large subfloor section, and (6) a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Finite element models of the composite specimens were developed and impact simulations were performed. The properties of the composite material were represented using both a progressive in-plane damage model (Mat 54) and a continuum damage mechanics model (Mat 58) in LS-DYNA. This paper provides test-analysis comparisons of time history responses and the location and type of damage for representative I-beam, T-section, and cruciform section components.

  17. Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph

    2014-01-01

    In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy

  18. Experiences at Langley Research Center in the application of optimization techniques to helicopter airframes for vibration reduction

    NASA Technical Reports Server (NTRS)

    Sreekanta Murthy, T.; Kvaternik, Raymond G.

    1991-01-01

    A NASA/industry rotorcraft structural dynamics program known as Design Analysis Methods for VIBrationS (DAMVIBS) was initiated at Langley Research Center in 1984 with the objective of establishing the technology base needed by the industry for developing an advanced finite-element-based vibrations design analysis capability for airframe structures. As a part of the in-house activities contributing to that program, a study was undertaken to investigate the use of formal, nonlinear programming-based, numerical optimization techniques for airframe vibrations design work. Considerable progress has been made in connection with that study since its inception in 1985. This paper presents a unified summary of the experiences and results of that study. The formulation and solution of airframe optimization problems are discussed. Particular attention is given to describing the implementation of a new computational procedure based on MSC/NASTRAN and CONstrained function MINimization (CONMIN) in a computer program system called DYNOPT for the optimization of airframes subject to strength, frequency, dynamic response, and fatigue constraints. The results from the application of the DYNOPT program to the Bell AH-1G helicopter are presented and discussed.

  19. Ground shake test of the UH-60A helicopter airframe and comparison with NASTRAN finite element model predictions

    NASA Technical Reports Server (NTRS)

    Howland, G. R.; Durno, J. A.; Twomey, W. J.

    1990-01-01

    Sikorsky Aircraft, together with the other major helicopter airframe manufacturers, is engaged in a study to improve the use of finite element analysis to predict the dynamic behavior of helicopter airframes, under a rotorcraft structural dynamics program called DAMVIBS (Design Analysis Methods for VIBrationS), sponsored by the NASA-Langley. The test plan and test results are presented for a shake test of the UH-60A BLACK HAWK helicopter. A comparison is also presented of test results with results obtained from analysis using a NASTRAN finite element model.

  20. An advanced arc track resistant airframe wire

    NASA Technical Reports Server (NTRS)

    Beatty, J.

    1995-01-01

    Tensolite, a custom cable manufacturer specializing in high temperature materials as the dielectric medium, develops an advance arc track resistant airframe wire called Tufflite 2000. Tufflite 2000 has the following advantages over the other traditional wires: lighter weight and smaller in diameter; excellent wet and dry arc track resistance; superior dynamic cut-through performance even at elevated temperatures; flight proven performance on Boeing 737 and 757 airplanes; and true 260 C performance by utilizing Nickel plated copper conductors. This paper reports the different tests performed on Tufflite 2000: accelerated aging, arc resistance (wet and dry), dynamic cut through, humidity resistance, wire-to-wire abrasion, flammability, smoke, weight, notch sensitivity, flexibility, and markability. It particularly focuses on the BSI (British Standards Institute) dry arc resistance test and BSI wet arc tracking.

  1. Aerodynamics of a rolling airframe missile

    NASA Astrophysics Data System (ADS)

    Tisserand, L. E.

    1981-05-01

    For guidance-related reasons, there is considerable interest in rolling missiles having single-plane steering capability. To aid the aerodynamic design of these airframes, a unique investigation into the aerodynamics of a rolling, steering missile has been carried out. It represents the first known attempt to measure in a wind tunnel the aerodynamic forces and moments that act on a spinning body-canard-tail configuration that exercises canard steering in phase with body roll position. Measurements were made with the model spinning at steady-state roll rates ranging from 15 to 40 Hz over an angle-of-attack range up to about 16 deg. This short, exploratory investigation has demonstrated that a better understanding and a more complete definition of the aerodynamics of rolling, steering vehicles can be developed by way of simulative wind-tunnel testing.

  2. Small Engine Technology (SET). Task 33: Airframe, Integration, and Community Noise Study

    NASA Technical Reports Server (NTRS)

    Lieber, Lys S.; Elkins, Daniel; Golub, Robert A. (Technical Monitor)

    2002-01-01

    Task Order 33 had four primary objectives as follows: (1) Identify and prioritize the airframe noise reduction technologies needed to accomplish the NASA Pillar goals for business and regional aircraft. (2) Develop a model to estimate the effect of jet shear layer refraction and attenuation of internally generated source noise of a turbofan engine on the aircraft system noise. (3) Determine the effect on community noise of source noise changes of a generic turbofan engine operating from sea level to 15,000 feet. (4) Support lateral attenuation experiments conducted by NASA Langley at Wallops Island, VA, by coordinating opportunities for Contractor Aircraft to participate as a noise source during the noise measurements. Noise data and noise prediction tools, including airframe noise codes, from the NASA Advanced Subsonic Technology (AST) program were applied to assess the current status of noise reduction technologies relative to the NASA pillar goals for regional and small business jet aircraft. In addition, the noise prediction tools were applied to evaluate the effectiveness of airframe-related noise reduction concepts developed in the AST program on reducing the aircraft system noise. The AST noise data and acoustic prediction tools used in this study were furnished by NASA.

  3. Hypersonic airbreathing propulsion/airframe integration

    NASA Technical Reports Server (NTRS)

    Weidner, John P.

    1992-01-01

    Recent interest in airbreathing hypersonic flight has centered around the need to develop advanced space launch systems which can reduce the cost of inserting payloads in orbit and make space more accessible. An effect of the thermal environment is to require the vehicle to operate at high altitudes, in very thin air, to maintain aircraft structural load limits. The high altitudes at which the hypersonic vehicle must operate give rise to the concept of an airframe integrated propulsion system to provide a much larger inlet and nozzle to process the required volume of air at low density, atmospheric conditions. In the integrated system, the forward portion of the vehicle compresses the air flow and serves as the external portion of the inlet; the aftbody completes the expansion process for the nozzle. In addition, the engine, which is contained between the body and the forebody shock wave, lends itself to a modular integration of a number of separate engines. In this manner, a relatively small engine can be defined to allow engine development in existing ground facilities.

  4. Airframe Noise Prediction Using the Sngr Method

    NASA Astrophysics Data System (ADS)

    Chen, Rongqian; Wu, Yizhao; Xia, Jian

    In this paper, the Stochastic Noise Generation and Radiation method (SNGR) is used to predict airframe noise. The SNGR method combines a stochastic model with Computational Fluid Dynamics (CFD), and it can give acceptable noise results while the computation cost is relatively low. In the method, the time-averaged mean flow field is firstly obtained by solving Reynolds Averaged Navier-Stokes equations (RANS), and a stochastic velocity is generated based on the obtained information. Then the turbulent field is used to generate the source for the Acoustic Perturbation Equations (APEs) that simulate the noise propagation. For numerical methods, timeaveraged RANS equations are solved by finite volume method, and the turbulent model is K - ɛ model; APEs are solved by finite difference method, and the numerical scheme is the Dispersion-Relation-Preserving (DRP) scheme, with explicit optimized 5-stage Rung-Kutta scheme time step. In order to test the APE solver, propagation of a Gaussian pulse in a uniform mean flow is firstly simulated and compared with the analytical solution. Then, using the method, the trailing edge noise of NACA0012 airfoil is calculated. The results are compared with reference data, and good agreements are demonstrated.

  5. Design and Test of an Improved Crashworthiness Small Composite Airframe

    NASA Technical Reports Server (NTRS)

    Terry, James E.; Hooper, Steven J.; Nicholson, Mark

    2002-01-01

    The purpose of this small business innovative research (SBIR) program was to evaluate the feasibility of developing small composite airplanes with improved crashworthiness. A combination of analysis and half scale component tests were used to develop an energy absorbing airframe. Four full scale crash tests were conducted at the NASA Impact Dynamics Research Facility, two on a hard surface and two onto soft soil, replicating earlier NASA tests of production general aviation airplanes. Several seat designs and restraint systems including both an air bag and load limiting shoulder harnesses were tested. Tests showed that occupant loads were within survivable limits with the improved structural design and the proper combination of seats and restraint systems. There was no loss of cabin volume during the events. The analysis method developed provided design guidance but time did not allow extending the analysis to soft soil impact. This project demonstrated that survivability improvements are possible with modest weight penalties. The design methods can be readily applied by airplane designers using the examples in this report.

  6. Optimization of helicopter airframe structures for vibration reduction considerations, formulations and applications

    NASA Technical Reports Server (NTRS)

    Murthy, T. Sreekanta

    1988-01-01

    Several key issues involved in the application of formal optimization technique to helicopter airframe structures for vibration reduction are addressed. Considerations which are important in the optimization of real airframe structures are discussed. Considerations necessary to establish relevant set of design variables, constraints and objectives which are appropriate to conceptual, preliminary, detailed design, ground and flight test phases of airframe design are discussed. A methodology is suggested for optimization of airframes in various phases of design. Optimization formulations that are unique to helicopter airframes are described and expressions for vibration related functions are derived. Using a recently developed computer code, the optimization of a Bell AH-1G helicopter airframe is demonstrated.

  7. Aeroacoustics of Propulsion Airframe Integration: Overview of NASA's Research

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.

    2003-01-01

    The integration of propulsion and airframe is fundamental to the design of an aircraft system. Many considerations influence the integration, such as structural, aerodynamic, and maintenance factors. In regard to the acoustics of an aircraft, the integration can have significant effects on the net radiated noise. Whether an engine is mounted above a wing or below can have a significant effect on noise that reaches communities below because of shielding or reflection of engine noise. This is an obvious example of the acoustic effects of propulsion airframe installation. Another example could be the effect of the pylon on the development of the exhaust plume and on the resulting jet noise. In addition, for effective system noise reduction the impact that installation has on noise reduction devices developed on isolated components must be understood. In the future, a focus on the aerodynamic and acoustic interaction effects of installation, propulsion airframe aeroacoustics, will become more important as noise reduction targets become more difficult to achieve. In addition to continued fundamental component reduction efforts, a system level approach that includes propulsion airframe aeroacoustics will be required in order to achieve the 20 dB of perceived noise reduction envisioned by the long-range NASA goals. This emphasis on the aeroacoustics of propulsion airframe integration is a new part of NASA s noise research. The following paper will review current efforts and highlight technical challenges and approaches.

  8. Open Rotor Aeroacoustic Installation Effects for Conventional and Unconventional Airframes

    NASA Technical Reports Server (NTRS)

    Czech, Michael J.; Thomas, Russell H.

    2013-01-01

    As extensive experimental campaign was performed to study the aeroacoustic installation effects of an open rotor with respect to both a conventional tube and wing type airframe and an unconventional hybrid wing body airframe. The open rotor rig had two counter rotating rows of blades each with eight blades of a design originally flight tested in the 1980s. The aeroacoustic installation effects measured in an aeroacoustic wind tunnel included those from flow effects due to inflow distortion or wake interaction and acoustic propagation effects such as shielding and reflection. The objective of the test campaign was to quantify the installation effects for a wide range of parameters and configurations derived from the two airframe types. For the conventional airframe, the open rotor was positioned in increments in front of and then over the main wing and then in positions representative of tail mounted aircraft with a conventional tail, a T-tail and a U-tail. The interaction of the wake of the open rotor as well as acoustic scattering results in an increase of about 10 dB when the rotor is positioned in front of the main wing. When positioned over the main wing a substantial amount of noise reduction is obtained and this is also observed for tail-mounted installations with a large U-tail. For the hybrid wing body airframe, the open rotor was positioned over the airframe along the centerline as well as off-center representing a twin engine location. A primary result was the documentation of the noise reduction from shielding as a function of the location of the open rotor upstream of the trailing edge of the hybrid wing body. The effects from vertical surfaces and elevon deflection were also measured. Acoustic lining was specially designed and inserted flush with the elevon and airframe surface, the result was an additional reduction in open rotor noise propagating to the far field microphones. Even with the older blade design used, the experiment provided

  9. Interaction of power plant with airframe of new generation aircraft

    NASA Astrophysics Data System (ADS)

    Baklanov, V.

    2013-03-01

    Strategic development of new generation airplanes goes in the direction of further noise decreasing and increasing fuel efficiency, where the determining role belongs to superhigh bypass ratio engines, especially with application gearbox scheme. Fan shaft components will determine the spectrum of power plant dynamic effect transferred via mounting assembly (engine attachments) on airframe structure. This spectrum is reradiated into the cabin in the form of structural noise. Long-term researches of engines (with different bypass ratio) and airframe have allowed (i) to calculate expected structural noise on the new generation aircraft; and (ii) to offer the concept of new vibration isolation mounting.

  10. Simulations & Measurements of Airframe Noise: A BANC Workshops Perspective

    NASA Technical Reports Server (NTRS)

    Choudhari, Meelan; Lockard, David

    2016-01-01

    Airframe noise corresponds to the acoustic radiation due to turbulent flow in the vicinity of airframe components such as high-lift devices and landing gears. Since 2010, the American Institute of Aeronautics and Astronautics has organized an ongoing series of workshops devoted to Benchmark Problems for Airframe Noise Computations (BANC). The BANC workshops are aimed at enabling a systematic progress in the understanding and high-fidelity predictions of airframe noise via collaborative investigations that integrate computational fluid dynamics, computational aeroacoustics, and in depth measurements targeting a selected set of canonical yet realistic configurations that advance the current state-of-the-art in multiple respects. Unique features of the BANC Workshops include: intrinsically multi-disciplinary focus involving both fluid dynamics and aeroacoustics, holistic rather than predictive emphasis, concurrent, long term evolution of experiments and simulations with a powerful interplay between the two, and strongly integrative nature by virtue of multi-team, multi-facility, multiple-entry measurements. This paper illustrates these features in the context of the BANC problem categories and outlines some of the challenges involved and how they were addressed. A brief summary of the BANC effort, including its technical objectives, strategy, and selective outcomes thus far is also included.

  11. Computational Structures Technology for Airframes and Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Housner, Jerrold M. (Compiler); Starnes, James H., Jr. (Compiler); Hopkins, Dale A. (Compiler); Chamis, Christos C. (Compiler)

    1992-01-01

    This conference publication contains the presentations and discussions from the joint University of Virginia (UVA)/NASA Workshops. The presentations included NASA Headquarters perspectives on High Speed Civil Transport (HSCT), goals and objectives of the UVA Center for Computational Structures Technology (CST), NASA and Air Force CST activities, CST activities for airframes and propulsion systems in industry, and CST activities at Sandia National Laboratory.

  12. Novel inlet-airframe integration methodology for hypersonic waverider vehicles

    NASA Astrophysics Data System (ADS)

    Ding, Feng; Liu, Jun; Shen, Chi-bing; Huang, Wei

    2015-06-01

    With the aim of integrating a ramjet or scramjet with an airframe, a novel inlet-airframe integration methodology for the hypersonic waverider vehicle is proposed. For this newly proposed design concept and for the specified flight conditions, not only the forebody of the vehicle but also its engine cowl and wings can ride on the bow shock wave, causing the bow shock wave to remain attached to the leading edge for the entire length of the vehicle. Thus, this integrated vehicle can take full advantage of the waverider's high lift-to-drag ratio characteristics and the ideal pre-compression surface for the engine. In this work, a novel inlet-airframe integrated axisymmetric basic flow model that accounts for both external and internal flows is first designed using the method of characteristics and the streamline tracing technique. Subsequently, the design of the inlet-airframe integrated waverider vehicle is generated from the integrated axisymmetric basic flow model using the streamline tracing technique. Then, the design methodologies of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are verified by a computational numerical method. Finally, the viscous effects and performance of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are analysed under the design condition using the numerical computation. The obtained results show that the proposed approach is effective in designing the integrated hypersonic waverider vehicle.

  13. Design of an integrated airframe/propulsion control system architecture

    NASA Technical Reports Server (NTRS)

    Cohen, Gerald C.; Lee, C. William; Strickland, Michael J.; Torkelson, Thomas C.

    1990-01-01

    The design of an integrated airframe/propulsion control system architecture is described. The design is based on a prevalidation methodology that uses both reliability and performance. A detailed account is given for the testing associated with a subset of the architecture and concludes with general observations of applying the methodology to the architecture.

  14. Aviation Maintenance Technology. Airframe. A204. Aircraft Welding. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This teacher's guide is designed to aid teachers in leading students through a module on aircraft welding on airframes. The module contains four units that cover the following topics: (1) gas welding and cutting; (2) brazing and soldering; (3) shielded metal arc welding; and (4) gas tungsten arc welding. Each unit follows a standardized format…

  15. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... titanium. (1) 18. Solder stainless steel. (1) 19. Fabricate tubular structures. (2) 20. Solder, braze, gas... control systems. j. fire protection systems (1) 54. Inspect, check, and service smoke and carbon monoxide... of proficiency at which that item must be taught. I. Airframe Structures Teaching level a....

  16. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... titanium. (1) 18. Solder stainless steel. (1) 19. Fabricate tubular structures. (2) 20. Solder, braze, gas... control systems. j. fire protection systems (1) 54. Inspect, check, and service smoke and carbon monoxide... of proficiency at which that item must be taught. I. Airframe Structures Teaching level a....

  17. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... titanium. (1) 18. Solder stainless steel. (1) 19. Fabricate tubular structures. (2) 20. Solder, braze, gas... control systems. j. fire protection systems (1) 54. Inspect, check, and service smoke and carbon monoxide... of proficiency at which that item must be taught. I. Airframe Structures Teaching level a....

  18. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... titanium. (1) 18. Solder stainless steel. (1) 19. Fabricate tubular structures. (2) 20. Solder, braze, gas... control systems. j. fire protection systems (1) 54. Inspect, check, and service smoke and carbon monoxide... of proficiency at which that item must be taught. I. Airframe Structures Teaching level a....

  19. Identification of Best Practices for Resident Aesthetic Clinics in Plastic Surgery Training: The ACAPS National Survey

    PubMed Central

    Wu, Cindy; Bentz, Michael L.; Redett, Richard J.; Shack, R. Bruce; David, Lisa R.; Taub, Peter J.; Janis, Jeffrey E.

    2015-01-01

    Introduction: Resident aesthetic clinics (RACs) have demonstrated good outcomes and acceptable patient satisfaction, but few studies have evaluated their educational, financial, or medicolegal components. We sought to determine RAC best practices. Methods: We surveyed American Council of Academic Plastic Surgeon members (n = 399), focusing on operational details, resident supervision, patient safety, medicolegal history, financial viability, and research opportunities. Of the 96 respondents, 63 reported having a RAC, and 56% of plastic surgery residency program directors responded. Results: RACs averaged 243 patient encounters and 53.9 procedures annually, having been in existence for 19.6 years (mean). Full-time faculty (73%) supervised chief residents (84%) in all aspects of care (65%). Of the 63 RACs, 45 were accredited, 40 had licensed procedural suites, 28 had inclusion/exclusion criteria, and 31 used anesthesiologists. Seventeen had overnight capability, and 17 had a Life Safety Plan. No cases of malignant hyperthermia occurred, but 1 facility death was reported. Sixteen RACs had been involved in a lawsuit, and 33 respondents reported financial viability of the RACs. Net revenue was transferred to both the residents’ educational fund (41%) and divisional/departmental overhead (37%). Quality measures included case logs (78%), morbidity/mortality conference (62%), resident surveys (52%), and patient satisfaction scores (46%). Of 63 respondents, 14 have presented or published RAC-specific research; 80 of 96 of those who were surveyed believed RACs enhanced education. Conclusions: RACs are an important component of plastic surgery education. Most clinics are financially viable but carry high malpractice risk and consume significant resources. Best practices, to maximize patient safety and optimize resident education, include use of accredited procedural rooms and direct faculty supervision of all components of care. PMID:26146599

  20. Estrogen replacement therapy and progression of intimal-medial thickness in the carotid arteries of postmenopausal women. ACAPS Investigators. Asymptomatic Carotid Atherosclerosis Progression Study.

    PubMed

    Espeland, M A; Applegate, W; Furberg, C D; Lefkowitz, D; Rice, L; Hunninghake, D

    1995-11-15

    The effect of estrogen replacement therapy (ERT) on 3-year changes in carotid intimal-medial thickness (IMT) was explored using serial B-mode ultrasound measurements collected during 1989-1993 as part of the Asymptomatic Carotid Atherosclerotic Progression Study (ACAPS). Eligibility included increased IMT and elevated low density lipoprotein cholesterol. Of the 186 postmenopausal ACAPS women randomly assigned to receive either placebo or lovastatin, 34% reported use of ERT. Users tended to be younger than nonusers by an average of 3 years, to have more favorable high and low density lipoprotein cholesterol levels, and to be more likely to have had hysterectomies. Baseline blood pressure, body mass index, and cross-sectional IMT were similar among ERT users and nonusers. In the placebo group, IMT tended to progress among ERT nonusers but to regress among ERT users: Mean covariate-adjusted progression rates were 0.015 +/- 0.007 mm/year versus -0.012 +/- 0.012 mm/year, respectively (p = 0.05). This difference appeared to be independent of lipoprotein concentrations. Lovastatin was associated with an approximately 25% lowering of low density lipoprotein cholesterol among both ERT users and nonusers and had a marked impact on IMT progression (p = 0.004) in these women. ERT appeared to have little additional effect on IMT in women assigned to lovastatin. ERT may reduce or halt the progression of early atherosclerosis in women not receiving active lipid-lowering medication.

  1. Simulating the Impact Response of Full-Scale Composite Airframe Structures

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Jackson, Karen E.; Littell, Justin D.; Seal, Michael D.

    2012-01-01

    NASA Langley Research Center obtained a composite helicopter cabin structure in 2010 from the US Army's Survivable Affordable Repairable Airframe Program (SARAP) that was fabricated by Sikorsky Aircraft Corporation. The cabin had been subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead masses into the fuselage cabin. Damage to the cabin test article was limited primarily to the roof. Consequently, the roof area was removed and the remaining structure was cut into test specimens including a large subfloor section and a forward framed fuselage section. In 2011, NASA and Sikorsky entered into a cooperative research agreement to study the impact responses of composite airframe structures and to evaluate the capabilities of the explicit transient dynamic finite element code, LS-DYNA®, to simulate these responses including damage initiation and progressive failure. Most of the test articles were manufactured of graphite unidirectional tape composite with a thermoplastic resin system. However, the framed fuselage section was constructed primarily of a plain weave graphite fabric material with a thermoset resin system. Test data were collected from accelerometers and full-field photogrammetry. The focus of this paper will be to document impact testing and simulation results for the longitudinal impact of the subfloor section and the vertical drop test of the forward framed fuselage section.

  2. The Prediction and Analysis of Jet Flows and Scattered Turbulent Mixing Noise about Flight Vehicle Airframes

    NASA Technical Reports Server (NTRS)

    Miller, Steven A. E.

    2014-01-01

    Jet flows interacting with nearby surfaces exhibit a complex behavior in which acoustic and aerodynamic characteristics are altered. The physical understanding and prediction of these characteristics are essential to designing future low noise aircraft. A new approach is created for predicting scattered jet mixing noise that utilizes an acoustic analogy and steady Reynolds-averaged Navier-Stokes solutions. A tailored Green's function accounts for the propagation of mixing noise about the airframe and is calculated numerically using a newly developed ray tracing method. The steady aerodynamic statistics, associated unsteady sound source, and acoustic intensity are examined as jet conditions are varied about a large flat plate. A non-dimensional number is proposed to estimate the effect of the aerodynamic noise source relative to jet operating condition and airframe position.The steady Reynolds-averaged Navier-Stokes solutions, acoustic analogy, tailored Green's function, non-dimensional number, and predicted noise are validated with a wide variety of measurements. The combination of the developed theory, ray tracing method, and careful implementation in a stand-alone computer program result in an approach that is more first principles oriented than alternatives, computationally efficient, and captures the relevant physics of fluid-structure interaction.

  3. An Assessment of IMPAC - Integrated Methodology for Propulsion and Airframe Controls

    NASA Technical Reports Server (NTRS)

    Walker, G. P.; Wagner, E. A.; Bodden, D. S.

    1996-01-01

    This report documents the work done under a NASA sponsored contract to transition to industry technologies developed under the NASA Lewis Research Center IMPAC (Integrated Methodology for Propulsion and Airframe Control) program. The critical steps in IMPAC are exercised on an example integrated flight/propulsion control design for linear airframe/engine models of a conceptual STOVL (Short Take-Off and Vertical Landing) aircraft, and MATRIXX (TM) executive files to implement each step are developed. The results from the example study are analyzed and lessons learned are listed along with recommendations that will improve the application of each design step. The end product of this research is a set of software requirements for developing a user-friendly control design tool which will automate the steps in the IMPAC methodology. Prototypes for a graphical user interface (GUI) are sketched to specify how the tool will interact with the user, and it is recommended to build the tool around existing computer aided control design software packages.

  4. The Prediction and Analysis of Jet Flows and Scattered Turbulent Mixing Noise About Flight Vehicle Airframes

    NASA Technical Reports Server (NTRS)

    Miller, Steven A.

    2014-01-01

    Jet flows interacting with nearby surfaces exhibit a complex behavior in which acoustic and aerodynamic characteristics are altered. The physical understanding and prediction of these characteristics are essential to designing future low noise aircraft. A new approach is created for predicting scattered jet mixing noise that utilizes an acoustic analogy and steady Reynolds-averaged Navier-Stokes solutions. A tailored Green's function accounts for the propagation of mixing noise about the air-frame and is calculated numerically using a newly developed ray tracing method. The steady aerodynamic statistics, associated unsteady sound source, and acoustic intensity are examined as jet conditions are varied about a large at plate. A non-dimensional number is proposed to estimate the effect of the aerodynamic noise source relative to jet operating condition and airframe position. The steady Reynolds-averaged Navier-Stokes solutions, acoustic analogy, tailored Green's function, non- dimensional number, and predicted noise are validated with a wide variety of measurements. The combination of the developed theory, ray tracing method, and careful implementation in a stand-alone computer program result in an approach that is more first principles oriented than alternatives, computationally efficient, and captures the relevant physics of fluid-structure interaction.

  5. Advanced general aviation comparative engine/airframe integration study

    NASA Technical Reports Server (NTRS)

    Huggins, G. L.; Ellis, D. R.

    1981-01-01

    The NASA Advanced Aviation Comparative Engine/Airframe Integration Study was initiated to help determine which of four promising concepts for new general aviation engines for the 1990's should be considered for further research funding. The engine concepts included rotary, diesel, spark ignition, and turboprop powerplants; a conventional state-of-the-art piston engine was used as a baseline for the comparison. Computer simulations of the performance of single and twin engine pressurized aircraft designs were used to determine how the various characteristics of each engine interacted in the design process. Comparisons were made of how each engine performed relative to the others when integrated into an airframe and required to fly a transportation mission.

  6. Airframe Integration Trade Studies for a Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Wu, Chauncey; Rivers, Kevin; Martin, Carl; Smith, Russell

    1999-01-01

    Future launch vehicles must be lightweight, fully reusable and easily maintained if low-cost access to space is to be achieved. The goal of achieving an economically viable Single-Stage-to-Orbit (SSTO) Reusable Launch Vehicle (RLV) is not easily achieved and success will depend to a large extent on having an integrated and optimized total system. A series of trade studies were performed to meet three objectives. First, to provide structural weights and parametric weight equations as inputs to configuration-level trade studies. Second, to identify, assess and quantify major weight drivers for the RLV airframe. Third, using information on major weight drivers, and considering the RLV as an integrated thermal structure (composed of thrust structures, tanks, thermal protection system, insulation and control surfaces), identify and assess new and innovative approaches or concepts that have the potential for either reducing airframe weight, improving operability, and/or reducing cost.

  7. NASA Airframe Icing Research Overview Past and Current

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark

    2009-01-01

    This slide presentation reviews the past and current research that NASA has done in the area of airframe icing. Both the history experimental efforts and model development to understand the process and problem of ice formation are reviewed. This has resulted in the development of new experimental methods, advanced icing simulation software, flight dynamics and experimental databases that have an impact on design, testing, construction and certification and qualification of the aircraft and its sub-systems.

  8. Analysis of small crack behavior for airframe applications

    NASA Technical Reports Server (NTRS)

    Mcclung, R. C.; Chan, K. S.; Hudak, S. J., Jr.; Davidson, D. L.

    1994-01-01

    The small fatigue crack problem is critically reviewed from the perspective of airframe applications. Different types of small cracks-microstructural, mechanical, and chemical-are carefully defined and relevant mechanisms identified. Appropriate analysis techniques, including both rigorous scientific and practical engineering treatments, are briefly described. Important materials data issues are addressed, including increased scatter in small crack data and recommended small crack test methods. Key problems requiring further study are highlighted.

  9. Advanced general aviation engine/airframe integration study

    NASA Technical Reports Server (NTRS)

    Zmroczek, L. A.

    1982-01-01

    A comparison of the in-airframe performance and efficiency of the advanced engine concepts is presented. The results indicate that the proposed advanced engines can significantly improve the performance and economy of general aviation airplanes. The engine found to be most promising is the highly advanced version of a rotary combustion (Wankel) engine. The low weight and fuel consumption of this engine, as well as its small size, make it suited for aircraft use.

  10. Design of an integrated airframe/propulsion control system architecture

    NASA Technical Reports Server (NTRS)

    Cohen, Gerald C.; Lee, C. William; Strickland, Michael J.

    1990-01-01

    The design of an integrated airframe/propulsion control system architecture is described. The design is based on a prevalidation methodology that used both reliability and performance tools. An account is given of the motivation for the final design and problems associated with both reliability and performance modeling. The appendices contain a listing of the code for both the reliability and performance model used in the design.

  11. Fluidic actuators for active flow control on airframe

    NASA Astrophysics Data System (ADS)

    Schueller, M.; Weigel, P.; Lipowski, M.; Meyer, M.; Schlösser, P.; Bauer, M.

    2016-04-01

    One objective of the European Projects AFLoNext and Clean Sky 2 is to apply Active Flow Control (AFC) on the airframe in critical aerodynamic areas such as the engine/wing junction or the outer wing region for being able to locally improve the aerodynamics in certain flight conditions. At the engine/wing junction, AFC is applied to alleviate or even eliminate flow separation at low speeds and high angle of attacks likely to be associated with the integration of underwing- mounted Ultra High Bypass Ratio (UHBR) engines and the necessary slat-cut-outs. At the outer wing region, AFC can be used to allow more aggressive future wing designs with improved performance. A relevant part of the work on AFC concepts for airframe application is the development of suitable actuators. Fluidic Actuated Flow Control (FAFC) has been introduced as a Flow Control Technology that influences the boundary layer by actively blowing air through slots or holes out of the aircraft skin. FAFC actuators can be classified by their Net Mass Flux and accordingly divided into ZNMF (Zero Net Mass Flux) and NZNMF (Non Zero Net-Mass-Flux) actuators. In the frame of both projects, both types of the FAFC actuator concepts are addressed. In this paper, the objectives of AFC on the airframe is presented and the actuators that are used within the project are discussed.

  12. Experimental Analysis of Flow over a Highly Maneuverable Airframe

    NASA Astrophysics Data System (ADS)

    Spirnak, Jonathan; Benson, Michael; van Poppel, Bret; Elkins, Christopher; Eaton, John; Team HMA Team

    2015-11-01

    One way to reduce the collateral damage in war is by increasing the accuracy of indirect fire weapons. The Army Research Laboratory is currently developing a Highly Maneuverable Airframe (HMA) consisting of four deflecting canards to provide in-flight maneuverability while fins maintain short duration aerodynamic stability. An experiment was conducted using Magnetic Resonance Velocimetry (MRV) techniques to gather three dimensional, three-component velocity data for fluid flow over a scaled down HMA model. Tests were performed at an angle of attack of 2.3° and canard deflection angles of 0° and 2°. The resulting data serve to both validate computational fluid dynamics (CFD) simulations and understand the flow over this complex geometry. Particular interest is given to the development of the tip and inboard vortices that originate at the canard/body junction and the canard tips to determine their effects on airframe stability. Results show the development of a strong tip vortex and four weaker inboard vortices off each canard. Although the weaker inboard vortices dissipate rapidly downstream of the canard trailing edges, the stronger tip vortices persist until reaching the fins approximately six chord lengths downstream of the canard trailing edges. Team HMA designed and built the water channel and airframe for this experiment.

  13. Processing and Properties of Airframe Materials.

    DTIC Science & Technology

    1984-02-01

    the first year of the three-year program to characterize the relationship between microstruc - ture and fatigue behavior of beta processed Ti-6A1-4V...determine how the microstructural variables affect the macroscopic deformation behavior . Experiments have been performed with 7475 Al having various grain...sizes. The flow stress vs strain rate behavior for the mixed grain size materials is best described using the iso-strain rate concept. Observations of

  14. Advanced method and processing technology for complicated shape airframe part forming

    NASA Technical Reports Server (NTRS)

    Miodushevsky, P. V.; Rajevskaya, G. A.

    1994-01-01

    Slow deformation modes of forming give considerably higher residual fatigue life of the airframe part. It has experimentally proven that fatigue life of complicated shape integral airframe panels made of high strength aluminum alloys is significantly increased after creep deformation process. To implement the slow deformation mode forming methods, universal automated equipment was developed. Multichannel forming systems provide high accuracy of airframe part shape eliminating residual stresses and spring effect. Forming process multizone control technology was developed and experimentally proved that static/fatigue properties of formed airframe parts are increased.

  15. Crash Testing of Helicopter Airframe Fittings

    NASA Technical Reports Server (NTRS)

    Clarke, Charles W.; Townsend, William; Boitnott, Richard

    2004-01-01

    As part of the Rotary Wing Structures Technology Demonstration (RWSTD) program, a surrogate RAH-66 seat attachment fitting was dynamically tested to assess its response to transient, crash impact loads. The dynamic response of this composite material fitting was compared to the performance of an identical fitting subjected to quasi-static loads of similar magnitude. Static and dynamic tests were conducted of both smaller bench level and larger full-scale test articles. At the bench level, the seat fitting was supported in a steel fixture, and in the full-scale tests, the fitting was integrated into a surrogate RAH-66 forward fuselage. Based upon the lessons learned, an improved method to design, analyze, and test similar composite material fittings is proposed.

  16. Application of Circulation Control Technology to Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Sankar, L. N.; Englar, R. J.; Munro, Scott E.; Li, Yi; Gaeta, R. J.

    2003-01-01

    This report is a summary of the work performed by Georgia Tech Research Institute (GTRI) under NASA Langley Grant NAG-1-2146, which was awarded as a part of NASA's Breakthrough Innovative Technologies (BIT) initiative. This was a three-year program, with a one-year no-cost extension. Each year's study has been an integrated effort consisting of computational fluid dynamics, experimental aerodynamics, and detailed noise and flow measurements. Year I effort examined the feasibility of reducing airframe noise by replacing the conventional wing systems with a Circulation Control Wing (CCW), where steady blowing was used through the trailing edge of the wing over a Coanda surface. It was shown that the wing lift increases with CCW blowing and indeed for the same lift, a CCW wing was shown to produce less noise. Year 2 effort dealt with a similar study on the role of pulsed blowing on airframe noise. The main objective of this portion of the study was to assess whether pulse blowing from the trailing edge of a CCW resulted in more, less, or the same amount of radiated noise to the farfield. Results show that a reduction in farfield noise of up to 5 dB is measured when pulse flow is compared with steady flow for an equivalent lift configuration. This reduction is in the spectral region associated with the trailing edge jet noise. This result is due to the unique advantage that pulsed flow has over steady flow. For a range of frequencies, more lift is experienced with the same mass flow as the steady case. Thus, for an equivalent lift and slot height, the pulsed system can operate at lower jet velocities, and hence lower jet noise. The computational analysis showed that for a given time-averaged mass flow rate, pulsed jets give a higher value of C(sub l) and a higher L/D than equivalent steady jets. This benefit is attributable to higher instantaneous jet velocities, and higher instantaneous C(sub mu) values for the pulsed jet. Pulsed jet benefits increase at higher

  17. Health Monitoring for Airframe Structural Characterization

    NASA Technical Reports Server (NTRS)

    Munns, Thomas E.; Kent, Renee M.; Bartolini, Antony; Gause, Charles B.; Borinski, Jason W.; Dietz, Jason; Elster, Jennifer L.; Boyd, Clark; Vicari, Larry; Ray, Asok; Cooper, E. G. (Technical Monitor)

    2002-01-01

    This study established requirements for structural health monitoring systems, identified and characterized a prototype structural sensor system, developed sensor interpretation algorithms, and demonstrated the sensor systems on operationally realistic test articles. Fiber-optic corrosion sensors (i.e., moisture and metal ion sensors) and low-cycle fatigue sensors (i.e., strain and acoustic emission sensors) were evaluated to validate their suitability for monitoring aging degradation; characterize the sensor performance in aircraft environments; and demonstrate placement processes and multiplexing schemes. In addition, a unique micromachined multimeasure and sensor concept was developed and demonstrated. The results show that structural degradation of aircraft materials could be effectively detected and characterized using available and emerging sensors. A key component of the structural health monitoring capability is the ability to interpret the information provided by sensor system in order to characterize the structural condition. Novel deterministic and stochastic fatigue damage development and growth models were developed for this program. These models enable real time characterization and assessment of structural fatigue damage.

  18. Correlation of AH-1G airframe flight vibration data with a coupled rotor-fuselage analysis

    NASA Technical Reports Server (NTRS)

    Sangha, K.; Shamie, J.

    1990-01-01

    The formulation and features of the Rotor-Airframe Comprehensive Analysis Program (RACAP) is described. The analysis employs a frequency domain, transfer matrix approach for the blade structural model, a time domain wake or momentum theory aerodynamic model, and impedance matching for rotor-fuselage coupling. The analysis is applied to the AH-1G helicopter, and a correlation study is conducted on fuselage vibration predictions. The purpose of the study is to evaluate the state-of-the-art in helicopter fuselage vibration prediction technology. The fuselage vibration predicted using RACAP are fairly good in the vertical direction and somewhat deficient in the lateral/longitudinal directions. Some of these deficiencies are traced to the fuselage finite element model.

  19. Study of hypersonic propulsion/airframe integration technology

    NASA Technical Reports Server (NTRS)

    Hartill, W. R.; Goebel, T. P.; Vancamp, V. V.

    1978-01-01

    An assessment is done of current and potential ground facilities, and analysis and flight test techniques for establishing a hypersonic propulsion/airframe integration technology base. A mach 6 cruise prototype aircraft incorporating integrated Scramjet engines was considered the baseline configuration, and the assessment focused on the aerodynamic and configuration aspects of the integration technology. The study describes the key technology milestones that must be met to permit a decision on development of a prototype vehicle, and defines risk levels for these milestones. Capabilities and limitations of analysis techniques, current and potential ground test facilities, and flight test techniques are described in terms of the milestones and risk levels.

  20. Airframe-integrated propulsion system for hypersonic cruise vehicles

    NASA Technical Reports Server (NTRS)

    Jones, R. A.; Huber, P. W.

    1978-01-01

    Research on a new, hydrogen burning, airbreathing engine concept which offers good potential for efficient hypersonic cruise vehicles is considered. Features of the engine which lead to good performance include; extensive engine-airframe integration, fixed geometry, low cooling, and the control of heat release in the supersonic combustor by mixed-modes of fuel injection from the combustor entrance. The engine concept is described along with results from inlet tests, direct-connect combustor tests, and tests of two subscale boiler-plate research engines presently underway at conditions which simulate flight at Mach 4 and 7.

  1. Reliability-Based Design Optimization of a Composite Airframe Component

    NASA Technical Reports Server (NTRS)

    Pai, Shantaram S.; Coroneos, Rula; Patnaik, Surya N.

    2011-01-01

    A stochastic optimization methodology (SDO) has been developed to design airframe structural components made of metallic and composite materials. The design method accommodates uncertainties in load, strength, and material properties that are defined by distribution functions with mean values and standard deviations. A response parameter, like a failure mode, has become a function of reliability. The primitive variables like thermomechanical loads, material properties, and failure theories, as well as variables like depth of beam or thickness of a membrane, are considered random parameters with specified distribution functions defined by mean values and standard deviations.

  2. Development, documentation and correlation of a NASTRAN vibration model of the AH-1G helicopter airframe

    NASA Technical Reports Server (NTRS)

    Cronkhite, J. D.

    1976-01-01

    NASTRAN was evaluated for vibration analysis of the helicopter airframe. The first effort involved development of a NASTRAN model of the AH-1G helicopter airframe and comprehensive documentation of the model. The next effort was to assess the validity of the NASTRAN model by comparisons with static and vibration tests.

  3. Flight and wind-tunnel comparisons of the inlet-airframe interaction of the F-15 airplane

    NASA Technical Reports Server (NTRS)

    Webb, L. D.; Andriyich-Varda, D.; Whitmore, S. A.

    1984-01-01

    The design of inlets and nozzles and their interactions with the airplane which may account for a large percentage of the total drag of modern high performance aircraft is discussed. The inlet/airframe interactions program and the flight tests conducted is described. Inlet drag and lift data from a 7.5% wind-tunnel model are compared with data from an F-15 airplane with instrumentation to match the model. Pressure coefficient variations with variable cowl angles, capture ratios, examples of flow interactions and angles of attack are for Mach numbers of 0.6, 0.9, 1.2, and 1.5 are presented.

  4. Computational aeroelastic modelling of airframes and turbomachinery: progress and challenges.

    PubMed

    Bartels, R E; Sayma, A I

    2007-10-15

    Computational analyses such as computational fluid dynamics and computational structural dynamics have made major advances towards maturity as engineering tools. Computational aeroelasticity (CAE) is the integration of these disciplines. As CAE matures, it also finds an increasing role in the design and analysis of aerospace vehicles. This paper presents a survey of the current state of CAE with a discussion of recent research, success and continuing challenges in its progressive integration into multidisciplinary aerospace design. It approaches CAE from the perspective of the two main areas of application: airframe and turbomachinery design. An overview will be presented of the different prediction methods used for each field of application. Differing levels of nonlinear modelling will be discussed with insight into accuracy versus complexity and computational requirements. Subjects will include current advanced methods (linear and nonlinear), nonlinear flow models, use of order reduction techniques and future trends in incorporating structural nonlinearity. Examples in which CAE is currently being integrated into the design of airframes and turbomachinery will be presented.

  5. Investigation of Volumetric Sources in Airframe Noise Simulations

    NASA Technical Reports Server (NTRS)

    Casper, Jay H.; Lockard, David P.; Khorrami, Mehdi R.; Streett, Craig L.

    2004-01-01

    Hybrid methods for the prediction of airframe noise involve a simulation of the near field flow that is used as input to an acoustic propagation formula. The acoustic formulations discussed herein are those based on the Ffowcs Williams and Hawkings equation. Some questions have arisen in the published literature in regard to an apparently significant dependence of radiated noise predictions on the location of the integration surface used in the solution of the Ffowcs Williams and Hawkings equation. These differences in radiated noise levels are most pronounced between solid-body surface integrals and off-body, permeable surface integrals. Such differences suggest that either a non-negligible volumetric source is contributing to the total radiation or the input flow simulation is suspect. The focus of the current work is the issue of internal consistency of the flow calculations that are currently used as input to airframe noise predictions. The case study for this research is a computer simulation for a three-element, high-lift wing profile during landing conditions. The noise radiated from this flow is predicted by a two-dimensional, frequency-domain formulation of the Ffowcs Williams and Hawkings equation. Radiated sound from volumetric sources is assessed by comparison of a permeable surface integration with the sum of a solid-body surface integral and a volume integral. The separate noise predictions are found in good agreement.

  6. Unstructured CFD and Noise Prediction Methods for Propulsion Airframe Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Pao, S. Paul; Abdol-Hamid, Khaled S.; Campbell, Richard L.; Hunter, Craig A.; Massey, Steven J.; Elmiligui, Alaa A.

    2006-01-01

    Using unstructured mesh CFD methods for Propulsion Airframe Aeroacoustics (PAA) analysis has the distinct advantage of precise and fast computational mesh generation for complex propulsion and airframe integration arrangements that include engine inlet, exhaust nozzles, pylon, wing, flaps, and flap deployment mechanical parts. However, accurate solution values of shear layer velocity, temperature and turbulence are extremely important for evaluating the usually small noise differentials of potential applications to commercial transport aircraft propulsion integration. This paper describes a set of calibration computations for an isolated separate flow bypass ratio five engine nozzle model and the same nozzle system with a pylon. These configurations have measured data along with prior CFD solutions and noise predictions using a proven structured mesh method, which can be used for comparison to the unstructured mesh solutions obtained in this investigation. This numerical investigation utilized the TetrUSS system that includes a Navier-Stokes solver, the associated unstructured mesh generation tools, post-processing utilities, plus some recently added enhancements to the system. New features necessary for this study include the addition of two equation turbulence models to the USM3D code, an h-refinement utility to enhance mesh density in the shear mixing region, and a flow adaptive mesh redistribution method. In addition, a computational procedure was developed to optimize both solution accuracy and mesh economy. Noise predictions were completed using an unstructured mesh version of the JeT3D code.

  7. Airframe Noise from a Hybrid Wing Body Aircraft Configuration

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Spalt, Taylor B.; Brooks, Thomas F.; Plassman, Gerald E.

    2016-01-01

    A high fidelity aeroacoustic test was conducted in the NASA Langley 14- by 22-Foot Subsonic Tunnel to establish a detailed database of component noise for a 5.8% scale HWB aircraft configuration. The model has a modular design, which includes a drooped and a stowed wing leading edge, deflectable elevons, twin verticals, and a landing gear system with geometrically scaled wheel-wells. The model is mounted inverted in the test section and noise measurements are acquired at different streamwise stations from an overhead microphone phased array and from overhead and sideline microphones. Noise source distribution maps and component noise spectra are presented for airframe configurations representing two different approach flight conditions. Array measurements performed along the aircraft flyover line show the main landing gear to be the dominant contributor to the total airframe noise, followed by the nose gear, the inboard side-edges of the LE droop, the wing tip/LE droop outboard side-edges, and the side-edges of deployed elevons. Velocity dependence and flyover directivity are presented for the main noise components. Decorrelation effects from turbulence scattering on spectral levels measured with the microphone phased array are discussed. Finally, noise directivity maps obtained from the overhead and sideline microphone measurements for the landing gear system are provided for a broad range of observer locations.

  8. Integrating CFD, CAA, and Experiments Towards Benchmark Datasets for Airframe Noise Problems

    NASA Technical Reports Server (NTRS)

    Choudhari, Meelan M.; Yamamoto, Kazuomi

    2012-01-01

    Airframe noise corresponds to the acoustic radiation due to turbulent flow in the vicinity of airframe components such as high-lift devices and landing gears. The combination of geometric complexity, high Reynolds number turbulence, multiple regions of separation, and a strong coupling with adjacent physical components makes the problem of airframe noise highly challenging. Since 2010, the American Institute of Aeronautics and Astronautics has organized an ongoing series of workshops devoted to Benchmark Problems for Airframe Noise Computations (BANC). The BANC workshops are aimed at enabling a systematic progress in the understanding and high-fidelity predictions of airframe noise via collaborative investigations that integrate state of the art computational fluid dynamics, computational aeroacoustics, and in depth, holistic, and multifacility measurements targeting a selected set of canonical yet realistic configurations. This paper provides a brief summary of the BANC effort, including its technical objectives, strategy, and selective outcomes thus far.

  9. Analysis of airframe/engine interactions in integrated flight and propulsion control

    NASA Technical Reports Server (NTRS)

    Schierman, John D.; Schmidt, David K.

    1991-01-01

    An analysis framework for the assessment of dynamic cross-coupling between airframe and engine systems from the perspective of integrated flight/propulsion control is presented. This analysis involves to determining the significance of the interactions with respect to deterioration in stability robustness and performance, as well as critical frequency ranges where problems may occur due to these interactions. The analysis illustrated here investigates both the airframe's effects on the engine control loops and the engine's effects on the airframe control loops in two case studies. The second case study involves a multi-input/multi-output analysis of the airframe. Sensitivity studies are performed on critical interactions to examine the degradations in the system's stability robustness and performance. Magnitudes of the interactions required to cause instabilities, as well as the frequencies at which the instabilities occur are recorded. Finally, the analysis framework is expanded to include control laws which contain cross-feeds between the airframe and engine systems.

  10. SCRAM - AN ENGINEER'S TOOL FOR PREDICTION OF AIRFRAME INTEGRATED SCRAMJET PERFORMANCE

    NASA Technical Reports Server (NTRS)

    Walton, J. T.

    1994-01-01

    This program determines the one-dimensional performance for an airframe integrated supersonic combustion ramjet (scramjet). The supersonic combustion ramjet cycle, which uses hydrogen for fuel and atmospheric air for oxidation, is essential for the development of a propulsion system for single-stage-to-orbit aerospace vehicles. These vehicles are intended to be launched horizontally, as opposed to vertical launching for current space vehicles. In addition, they must achieve hypersonic flight to Mach 25 prior to orbital insertion into low Earth orbit. The propulsion system of these vehicles must be reusable, efficient, and cost effective. The scramjet cycle analysis code performs nose-to-tail, hydrogen fueled, Airframe Integrated Scramjet (AIS) simulation in a real gas flow with equilibrium thermodynamic properties. This allows ready generation of preliminary estimates for SCRAM cycle performance. SCRAM is a reliable, efficient, and speedy design tool that is useable on all standard computers down to IBM PC-AT compatible machines. Developed in the Hypersonic Propulsion Branch at NASA Langley Research Center for the Hypersonic Research Engine and Langley 3-Strut engine programs, the current version of this code has been modified by the NASA Dryden Flight Research Facility of the Ames Research Center for the purpose of supporting the Langley Strutless Parametric engine and National AeroSpace Plane (NASP) engine test programs. The current version of SCRAM optimizes the tradeoffs between the needs for computational speed, accuracy, and future modifications. The program utilizes a five station geometry model, with variable step size between each station, to analyze a vehicle nose-to-tail mass capture stream tube control-volume with real gas equilibrium flow properties. SCRAM applies the laws of Conservation of Mass, Momentum, and Energy across each step to calculate the changing flow parameters along the control volume. The code incorporates an integral boundary layer

  11. Prediction of jet exhaust noise on airframe surfaces during flight

    NASA Technical Reports Server (NTRS)

    Butzel, L. M.

    1981-01-01

    The behavior of pressure fluctuations measured on the airframe of a prototype high lift jet transport (YC-14) is presented. The data are characterized in terms of a particular jet exhaust flow field idealization, jet mixing noise, and exhaust shock noise. Generalized spectrum shapes and scaling relations for peak level and frequency of peak level are developed, and the frequency is found to depend on jet exhaust velocity and aircraft velocity. Comparisons are made with near-field engine exhaust noise of a conventional jet, and results suggest that the same two exhaust noises are important for both aircraft types. Surface fluctuating pressure data are assessed, and results suggest that the jet mixing and exhaust shock noise source characterizations for the YC-14 have useful applicability to conventionally configured jets.

  12. Corrosion and corrosion fatigue of airframe aluminum alloys

    NASA Technical Reports Server (NTRS)

    Chen, G. S.; Gao, M.; Harlow, D. G.; Wei, R. P.

    1994-01-01

    Localized corrosion and corrosion fatigue crack nucleation and growth are recognized as degradation mechanisms that effect the durability and integrity of commercial transport aircraft. Mechanically based understanding is needed to aid the development of effective methodologies for assessing durability and integrity of airframe components. As a part of the methodology development, experiments on pitting corrosion, and on corrosion fatigue crack nucleation and early growth from these pits were conducted. Pitting was found to be associated with constituent particles in the alloys and pit growth often involved coalescence of individual particle-nucleated pits, both laterally and in depth. Fatigue cracks typically nucleated from one of the larger pits that formed by a cluster of particles. The size of pit at which fatigue crack nucleates is a function of stress level and fatigue loading frequency. The experimental results are summarized, and their implications on service performance and life prediction are discussed.

  13. Light aircraft crash safety program

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Hayduk, R. J.

    1974-01-01

    NASA is embarked upon research and development tasks aimed at providing the general aviation industry with a reliable crashworthy airframe design technology. The goals of the NASA program are: reliable analytical techniques for predicting the nonlinear behavior of structures; significant design improvements of airframes; and simulated full-scale crash test data. The analytical tools will include both simplified procedures for estimating energy absorption characteristics and more complex computer programs for analysis of general airframe structures under crash loading conditions. The analytical techniques being developed both in-house and under contract are described, and a comparison of some analytical predictions with experimental results is shown.

  14. Reliability-Based Design Optimization of a Composite Airframe Component

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Pai, Shantaram S.; Coroneos, Rula M.

    2009-01-01

    A stochastic design optimization methodology (SDO) has been developed to design components of an airframe structure that can be made of metallic and composite materials. The design is obtained as a function of the risk level, or reliability, p. The design method treats uncertainties in load, strength, and material properties as distribution functions, which are defined with mean values and standard deviations. A design constraint or a failure mode is specified as a function of reliability p. Solution to stochastic optimization yields the weight of a structure as a function of reliability p. Optimum weight versus reliability p traced out an inverted-S-shaped graph. The center of the inverted-S graph corresponded to 50 percent (p = 0.5) probability of success. A heavy design with weight approaching infinity could be produced for a near-zero rate of failure that corresponds to unity for reliability p (or p = 1). Weight can be reduced to a small value for the most failure-prone design with a reliability that approaches zero (p = 0). Reliability can be changed for different components of an airframe structure. For example, the landing gear can be designed for a very high reliability, whereas it can be reduced to a small extent for a raked wingtip. The SDO capability is obtained by combining three codes: (1) The MSC/Nastran code was the deterministic analysis tool, (2) The fast probabilistic integrator, or the FPI module of the NESSUS software, was the probabilistic calculator, and (3) NASA Glenn Research Center s optimization testbed CometBoards became the optimizer. The SDO capability requires a finite element structural model, a material model, a load model, and a design model. The stochastic optimization concept is illustrated considering an academic example and a real-life raked wingtip structure of the Boeing 767-400 extended range airliner made of metallic and composite materials.

  15. Bibliography on propulsion airframe integration technologies for high-speed civil transport applications, 1980-1991

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Mizukami, Masashi

    1993-01-01

    NASA has initiated the High Speed Research (HSR) program with the goal to develop technologies for a new generation, economically viable, environmentally acceptable, supersonic transport (SST) called the High Speed Civil Transport (HSCT). A significant part of this effort is expected to be in multidisciplinary systems integration, such as in propulsion airframe integration (PAI). In order to assimilate the knowledge database on PAI for SST type aircraft, a bibliography on this subject was compiled. The bibliography with over 1200 entries, full abstracts, and indexes. Related topics are also covered, such as the following: engine inlets, engine cycles, nozzles, existing supersonic cruise aircraft, noise issues, computational fluid dynamics, aerodynamics, and external interference. All identified documents from 1980 through early 1991 are included; this covers the latter part of the NASA Supersonic Cruise Research (SCR) program and the beginnings of the HSR program. In addition, some pre-1980 documents of significant merit or reference value are also included. The references were retrieved via a computerized literature search using the NASA RECON database system.

  16. Analysis of a System to Prevent Helicopter Rotor Blade-Airframe Strikes

    DTIC Science & Technology

    1989-05-01

    airframe are particularly vulnerable: the tail boom, canopy and, in the case of the underslung, teetoring rotor, the rotor shaft. This latter case is...but they do occur. Three areas of the airframe are particularly vulnerable: the tail boom, canopy and, in the case of the underslung, teetoring rotor...particular vulnerable, the tail boom, canopy and, in the case of the underslung, teetoring rotor, the rotor shaft. This latter case, known as "mast

  17. Design of an airframe agnostic roll-on/roll-off (AA-RORO) sensor platform

    NASA Astrophysics Data System (ADS)

    Sparks, Bruce; Wowczuk, Zenovy S.; Harrison, A. Jay

    2009-05-01

    The US military has recently taken tactical steps to increase its ISR capabilities to support military operations. Due to the dynamic capabilities of the terrorist threat, there is a need for a payload- and airframe-agnostic, rapid-deployment sensor system that can be used on multiple airframes for in-theater missions and for the test and evaluation of sensors prior to fielding. This "plug-and-play" system, based upon the Oculus Sensor Deployment System technology, uses a system-of-systems approach to modularize the base platform, thereby allowing the system to conform to aircraft such as the C-130, C-27, V-22, CH-47, CH-53 and CASA-235 without any modification to the airframe itself. This type of system can be used as (1) a versatile, cost-effective test and evaluation platform for current and developmental sensors as well as (2) an in-theater ISR asset that can be used on readily available airframes at a particular location. This paper illustrates the CONUS and OCONUS mission potential of this multi-airframe system and outlines the novel design characteristics that the Airframe Agnostic Roll-on/Roll-off (AA-RORO) sensor platform incorporates to make it the most versatile, rapid-deployment sensor platform available to support near-term U.S. military operations. The system concept was developed with the support of and input from multiple military agencies and the respective branches they represent.

  18. Results from FAA program to validate bonded composite doublers for commercial aviation use

    SciTech Connect

    Roach, D.P.

    1997-09-01

    The number of commercial airframes exceeding twenty years of service continues to grow. In addition, Service Life Extension Programs are attempting to extend the {open_quotes}economic{close_quotes} service life of commercial airframes to thirty years. The use of bonded composites may offer the airframe manufacturers and aircraft maintenance facilities a cost effective method to extend the lives of their aircraft. The Federal Aviation Administration Assurance NDI Validation Center (AANC) to validate the use of bonded composite doublers on commercial aircraft.

  19. Structure-Function Analyses of the Small GTPase Rab35 and Its Effector Protein Centaurin-β2/ACAP2 during Neurite Outgrowth of PC12 Cells*

    PubMed Central

    Etoh, Kan; Fukuda, Mitsunori

    2015-01-01

    The small GTPase Rab35 is a molecular switch for membrane trafficking that regulates a variety of cellular events. We previously showed that Rab35 promotes neurite outgrowth of nerve growth factor-stimulated PC12 cells through interaction with centaurin-β2 (also called ACAP2). Centaurin-β2 is the only Rab35-binding protein reported thus far that exclusively recognizes Rab35 and does not recognize any of the other 59 Rabs identified in mammals, but the molecular basis for the exclusive specificity of centaurin-β2 for Rab35 has remained completely unknown. In this study, we performed deletion and mutation analyses and succeeded in identifying the residues of Rab35 and centaurin-β2 that are crucial for formation of a Rab35·centaurin-β2 complex. We found that two threonine residues (Thr-76 and Thr-81) in the switch II region of Rab35 are responsible for binding centaurin-β2 and that the same residues are dispensable for Rab35 recognition by other Rab35-binding proteins. We also determined the minimal Rab35-binding site of centaurin-β2 and identified two asparagine residues (Asn-610 and Asn-691) in the Rab35-binding site as key residues for its specific Rab35 recognition. We further showed by knockdown-rescue approaches that neither a centaurin-β2 binding-deficient Rab35(T76S/T81A) mutant nor a Rab35 binding-deficient centaurin-β2(N610A/N691A) mutant supported neurite outgrowth of PC12 cells, thereby demonstrating the functional significance of the Rab35/centaurin-β2 interaction during neurite outgrowth of PC12 cells. PMID:25694427

  20. In Search of the Physics: NASA's Approach to Airframe Noise

    NASA Technical Reports Server (NTRS)

    Macaraeg, Michele G.; Lockard, David P.; Streett, Craig L.

    1999-01-01

    An extensive numerical and experimental study of airframe noise mechanisms associated with a subsonic high-lift system has been performed at NASA Langley Research Center (LaRC). Investigations involving both steady and unsteady computations and experiments on small-scale models with part-span flaps and full-span flaps are presented. Both surface (steady and unsteady pressure measurements, hot films, oil flows, pressure sensitive paint) and off-surface (5 holeprobe, particle-imaged velocimetry, laser velocimetry, laser light sheet measurements) were taken in the LaRC Quiet Flow Facility (QFF) and several hard-wall tunnels. Experiments in the Low Turbulence Pressure Tunnel (LTPT) included Reynolds number variations up to flight conditions. Successful microphone array measurements were also taken providing both acoustic source maps on the model, and quantitative spectra. Critical directivity measurements were obtained in the QFF. NASA Langley unstructured and structured Reynolds-Averaged Navier-Stokes codes modeled the steady aspects of the flows. Excellent comparisons with surface and off-surface experimental data were obtained. Subsequently, these meanflow calculations were utilized in both linear stability and direct numerical simulations of the flow fields to calculate unsteady surface pressures and farfield acoustic spectra. Accurate calculations were critical in obtaining not only noise source characteristics, but shear layer correction data as well. Techniques utilized in these investigations as well as brief overviews of the results are given.

  1. Towards an Airframe Noise Prediction Methodology: Survey of Current Approaches

    NASA Technical Reports Server (NTRS)

    Farassat, Fereidoun; Casper, Jay H.

    2006-01-01

    In this paper, we present a critical survey of the current airframe noise (AFN) prediction methodologies. Four methodologies are recognized. These are the fully analytic method, CFD combined with the acoustic analogy, the semi-empirical method and fully numerical method. It is argued that for the immediate need of the aircraft industry, the semi-empirical method based on recent high quality acoustic database is the best available method. The method based on CFD and the Ffowcs William- Hawkings (FW-H) equation with penetrable data surface (FW-Hpds ) has advanced considerably and much experience has been gained in its use. However, more research is needed in the near future particularly in the area of turbulence simulation. The fully numerical method will take longer to reach maturity. Based on the current trends, it is predicted that this method will eventually develop into the method of choice. Both the turbulence simulation and propagation methods need to develop more for this method to become useful. Nonetheless, the authors propose that the method based on a combination of numerical and analytical techniques, e.g., CFD combined with FW-H equation, should also be worked on. In this effort, the current symbolic algebra software will allow more analytical approaches to be incorporated into AFN prediction methods.

  2. Tip Fence for Reduction of Lift-Generated Airframe Noise

    NASA Technical Reports Server (NTRS)

    Ross, James C. (Inventor); Storms, Bruce L. (Inventor)

    1998-01-01

    The present invention is directed toward a unique lift-generated noise reduction apparatus. This apparatus includes a plurality of tip fences that are secured to the trailing and leading assemblies of the high-lift system, as close as possible to the discontinuities where the vortices are most likely to form. In one embodiment, these tip fences are secured to some or all of the outboard and inboard tips of the wing slats and flaps. The tip fence includes a generally flat, or an aerodynamically shaped plate or device that could be formed of almost any rigid material, such as metal, wood, plastic, fiber glass, aluminum, etc. In a preferred embodiment, the tip fences extend below and perpendicularly to flaps and the slats to which they are attached, such that these tip fences are aligned with the nominal free stream velocity of the aircraft. In addition to reducing airframe noise, the tip fence tends to decrease drag and to increase lift, thus improving the overall aerodynamic performance of the aircraft. Another advantage presented by the tip fence lies in the simplicity of its design, its elegance, and its ready ability to fit on the wing components, such as the flaps and the slats. Furthermore, it does not require non-standard materials or fabrication techniques, and it can be readily, easily and inexpensively retrofited on most of the existing aircraft, with minimal design changes.

  3. Propulsion System Airframe Integration Issues and Aerodynamic Database Development for the Hyper-X Flight Research Vehicle

    NASA Technical Reports Server (NTRS)

    Engelund, Walter C.; Holland, Scott D.; Cockrell, Charles E., Jr.; Bittner, Robert D.

    1999-01-01

    NASA's Hyper-X Research Vehicle will provide a unique opportunity to obtain data on an operational airframe integrated scramjet propulsion system at true flight conditions. The airframe integrated nature of the scramjet engine with the Hyper-X vehicle results in a strong coupling effect between the propulsion system operation and the airframe s basic aerodynamic characteristics. Comments on general airframe integrated scramjet propulsion system effects on vehicle aerodynamic performance, stability, and control are provided, followed by examples specific to the Hyper-X research vehicle. An overview is provided of the current activities associated with the development of the Hyper-X aerodynamic database, including wind tunnel test activities and parallel CFD analysis efforts. A brief summary of the Hyper-X aerodynamic characteristics is provided, including the direct and indirect effects of the airframe integrated scramjet propulsion system operation on the basic airframe stability and control characteristics.

  4. Identification of integrated airframe: Propulsion effects on an F-15 aircraft for application to drag minimization

    NASA Technical Reports Server (NTRS)

    Schkolnik, Gerard S.

    1993-01-01

    The application of an adaptive real-time measurement-based performance optimization technique is being explored for a future flight research program. The key technical challenge of the approach is parameter identification, which uses a perturbation-search technique to identify changes in performance caused by forced oscillations of the controls. The controls on the NASA F-15 highly integrated digital electronic control (HIDEC) aircraft were perturbed using inlet cowl rotation steps at various subsonic and supersonic flight conditions to determine the effect on aircraft performance. The feasibility of the perturbation-search technique for identifying integrated airframe-propulsion system performance effects was successfully shown through flight experiments and postflight data analysis. Aircraft response and control data were analyzed postflight to identify gradients and to determine the minimum drag point. Changes in longitudinal acceleration as small as 0.004 g were measured, and absolute resolution was estimated to be 0.002 g or approximately 50 lbf of drag. Two techniques for identifying performance gradients were compared: a least-squares estimation algorithm and a modified maximum likelihood estimator algorithm. A complementary filter algorithm was used with the least squares estimator.

  5. Clean wing airframe noise modeling for multidisciplinary design and optimization

    NASA Astrophysics Data System (ADS)

    Hosder, Serhat

    A new noise metric has been developed that may be used for optimization problems involving aerodynamic noise from a clean wing. The modeling approach uses a classical trailing edge noise theory as the starting point. The final form of the noise metric includes characteristic velocity and length scales that are obtained from three-dimensional, steady, RANS simulations with a two equation k-o turbulence model. The noise metric is not the absolute value of the noise intensity, but an accurate relative noise measure as shown in the validation studies. One of the unique features of the new noise metric is the modeling of the length scale, which is directly related to the turbulent structure of the flow at the trailing edge. The proposed noise metric model has been formulated so that it can capture the effect of different design variables on the clean wing airframe noise such as the aircraft speed, lift coefficient, and wing geometry. It can also capture three dimensional effects which become important at high lift coefficients, since the characteristic velocity and the length scales are allowed to vary along the span of the wing. Noise metric validation was performed with seven test cases that were selected from a two-dimensional NACA 0012 experimental database. The agreement between the experiment and the predictions obtained with the new noise metric was very good at various speeds, angles of attack, and Reynolds Number, which showed that the noise metric is capable of capturing the variations in the trailing edge noise as a relative noise measure when different flow conditions and parameters are changed. Parametric studies were performed to investigate the effect of different design variables on the noise metric. Two-dimensional parametric studies were done using two symmetric NACA four-digit airfoils (NACA 0012 and NACA 0009) and two supercritical (SC(2)-0710 and SC(2)-0714) airfoils. The three-dimensional studies were performed with two versions of a conventional

  6. Investigation of Acoustical Shielding by a Wedge-Shaped Airframe

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Clark, Lorenzo R.; Dunn, Mark H.; Tweed, John

    2006-01-01

    Experiments on a scale model of an advanced unconventional subsonic transport concept, the Blended Wing Body (BWB), have demonstrated significant shielding of inlet-radiated noise. A computational model of the shielding mechanism has been developed using a combination of boundary integral equation method (BIEM) and equivalent source method (ESM). The computation models the incident sound from a point source in a nacelle and determines the scattered sound field. In this way the sound fields with and without the airfoil can be estimated for comparison to experiment. An experimental test bed using a simplified wedge-shape airfoil and a broadband point noise source in a simulated nacelle has been developed for the purposes of verifying the analytical model and also to study the effect of engine nacelle placement on shielding. The experimental study is conducted in the Anechoic Noise Research Facility at NASA Langley Research Center. The analytic and experimental results are compared at 6300 and 8000 Hz. These frequencies correspond to approximately 150 Hz on the full scale aircraft. Comparison between the experimental and analytic results is quite good, not only for the noise scattering by the airframe, but also for the total sound pressure in the far field. Many of the details of the sound field that the analytic model predicts are seen or indicated in the experiment, within the spatial resolution limitations of the experiment. Changing nacelle location produces comparable changes in noise shielding contours evaluated analytically and experimentally. Future work in the project will be enhancement of the analytic model to extend the analysis to higher frequencies corresponding to the blade passage frequency of the high bypass ratio ducted fan engines that are expected to power the BWB.

  7. Investigation of Acoustical Shielding by a Wedge-Shaped Airframe

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Clark, Lorenzo R.; Dunn, Mark H.; Tweed, John

    2004-01-01

    Experiments on a scale model of an advanced unconventional subsonic transport concept, the Blended Wing Body (BWB), have demonstrated significant shielding of inlet-radiated noise. A computational model of the shielding mechanism has been developed using a combination of boundary integral equation method (BIEM) and equivalent source method (ESM). The computation models the incident sound from a point source in a nacelle and determines the scattered sound field. In this way the sound fields with and without the airfoil can be estimated for comparison to experiment. An experimental test bed using a simplified wedge-shape airfoil and a broadband point noise source in a simulated nacelle has been developed for the purposes of verifying the analytical model and also to study the effect of engine nacelle placement on shielding. The experimental study is conducted in the Anechoic Noise Research Facility at NASA Langley Research Center. The analytic and experimental results are compared at 6300 and 8000 Hz. These frequencies correspond to approximately 150 Hz on the full scale aircraft. Comparison between the experimental and analytic results is quite good, not only for the noise scattering by the airframe, but also for the total sound pressure in the far field. Many of the details of the sound field that the analytic model predicts are seen or indicated in the experiment, within the spatial resolution limitations of the experiment. Changing nacelle location produces comparable changes in noise shielding contours evaluated analytically and experimentally. Future work in the project will be enhancement of the analytic model to extend the analysis to higher frequencies corresponding to the blade passage frequency of the high bypass ratio ducted fan engines that are expected to power the BWB.

  8. Towards Full Aircraft Airframe Noise Prediction: Lattice Boltzmann Simulations

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Fares, Ehab; Casalino, Damiano

    2014-01-01

    Computational results for an 18%-scale, semi-span Gulfstream aircraft model are presented. Exa Corporation's lattice Boltzmann PowerFLOW(trademark) solver was used to perform time-dependent simulations of the flow field associated with this high-fidelity aircraft model. The simulations were obtained for free-air at a Mach number of 0.2 with the flap deflected at 39 deg (landing configuration). We focused on accurately predicting the prominent noise sources at the flap tips and main landing gear for the two baseline configurations, namely, landing flap setting without and with gear deployed. Capitalizing on the inherently transient nature of the lattice Boltzmann formulation, the complex time-dependent flow features associated with the flap were resolved very accurately and efficiently. To properly simulate the noise sources over a broad frequency range, the tailored grid was very dense near the flap inboard and outboard tips. Extensive comparison of the computed time-averaged and unsteady surface pressures with wind tunnel measurements showed excellent agreement for the global aerodynamic characteristics and the local flow field at the flap inboard and outboard tips and the main landing gear. In particular, the computed fluctuating surface pressure field for the flap agreed well with the measurements in both amplitude and frequency content, indicating that the prominent airframe noise sources at the tips were captured successfully. Gear-flap interaction effects were remarkably well predicted and were shown to affect only the inboard flap tip, altering the steady and unsteady pressure fields in that region. The simulated farfield noise spectra for both baseline configurations, obtained using a Ffowcs-Williams and Hawkings acoustic analogy approach, were shown to be in close agreement with measured values.

  9. Vaccinia virus K1L protein supports viral replication in human and rabbit cells through a cell-type-specific set of its ankyrin repeat residues that are distinct from its binding site for ACAP2.

    PubMed

    Meng, Xiangzhi; Xiang, Yan

    2006-09-15

    Vaccinia virus (VV) K1L is a host-range gene and encodes a protein comprised of six ankyrin repeats (ANKs). We showed here that a large portion of the K1L protein, except ankyrin repeat 1 (ANK1) and C-terminal halves of ANK2 and ANK3, can be deleted or substituted with an unrelated ANK with no adverse effect on VV replication in human HeLa cells. In contrast, only ANK4 and ANK6 can be mutated without impairing VV replication in rabbit RK13 cells. The growth rate of VV in HeLa cells was reduced differentially by substituting phenylalanine 82 or serine 83 of ANK2 and abolished completely by substituting both residues. These substitutions, however, did not affect K1L's ability to bind ACAP2, a GTPase-activating protein for ARF6. Our data support the hypothesis that surface residues of a few consecutive K1L ANKs mediate the host-range function by interacting with protein factors that are distinct from ACAP2.

  10. Microstructural and Mechanical Characterization of Shear Formed Aluminum Alloys for Airframe and Space Applications

    NASA Technical Reports Server (NTRS)

    Troeger, L. P.; Domack, M. S.; Wagner, J. A.

    1998-01-01

    Advanced manufacturing processes such as near-net-shape forming can reduce production costs and increase the reliability of launch vehicle and airframe structural components through the reduction of material scrap and part count and the minimization of joints. The current research is an investigation of the processing-microstructure-property relationship for shear formed cylinders of the Al-Cu-Li-Mg-Ag alloy 2195 for space applications and the Al-Cu-Mg-Ag alloy C415 for airframe applications. Cylinders which have undergone various amounts of shear-forming strain have been studied to assess the microstructure and mechanical properties developed during and after shear forming.

  11. ICAM Manufacturing Cost/Design Guide. Volume 3. Airframes. User’s Manual.

    DTIC Science & Technology

    1983-01-01

    PER MATERIAL CUBIC INCH POUND ALUMINUM 705F -T6 -T652 r-T7352 TITANIUM 0.16 $30Ti6AI-4V LOW ALLOY STEEL 0.28 $3 4340 PH CRES $0.28 $7 15 - 5PH FIGURE...DG ...... ................ ... 3-3 3.3 Utilization of Learning Curve . . . . . . . . . 3-6 3.4 Cost Worksheet for Airframe Designers ...... 3-9 3.4.1...for Airframe Assemblies . 4.2- 15 4.2.5 Ground Rules for Mechanically Fastened Assembly Section .............. 4.2-27 4.2.5.1 General Ground Rules

  12. Airframe structural damage detection: a non-linear structural surface intensity based technique.

    PubMed

    Semperlotti, Fabio; Conlon, Stephen C; Barnard, Andrew R

    2011-04-01

    The non-linear structural surface intensity (NSSI) based damage detection technique is extended to airframe applications. The selected test structure is an upper cabin airframe section from a UH-60 Blackhawk helicopter (Sikorsky Aircraft, Stratford, CT). Structural damage is simulated through an impact resonator device, designed to simulate the induced vibration effects typical of non-linear behaving damage. An experimental study is conducted to prove the applicability of NSSI on complex mechanical systems as well as to evaluate the minimum sensor and actuator requirements. The NSSI technique is shown to have high damage detection sensitivity, covering an extended substructure with a single sensing location.

  13. An examination of the relations between rotor vibratory loads and airframe vibrations

    NASA Technical Reports Server (NTRS)

    Niebanck, C. F.

    1985-01-01

    Harmonic rotor hub loads and airframe interactions in steady flight are reviewed, with regard to the objective of achieving lower airframe vibration by modifying blade root loads. Flight test and wind tunnel data are reviewed, along with sample fuselage response data. Trends which could provide a generalized approach to the above objective are found to be very limited. Recent analytical and corresponding experimental blade tuning modifications are reviewed and compared. Rotor vibratory load modification and substantial vibration changes were achieved over a wide range of rotor operating conditions.

  14. Propulsion and airframe aerodynamic interactions of supersonic V/STOL configurations. Volume 1: Wind tunnel test pressure data report

    NASA Technical Reports Server (NTRS)

    Zilz, D. E.; Devereaux, P. A.

    1985-01-01

    A wind tunnel model of a supersonic V/STOL fighter configuration has been tested to measure the aerodynamic interaction effects which can result from geometrically close-coupled propulsion system/airframe components. The approach was to configure the model to represent two different test techniques. One was a conventional test technique composed of two test modes. In the Flow-Through mode, absolute configuration aerodynamics are measured, including inlet/airframe interactions. In the Jet-Effects mode, incremental nozzle/airframe interactions are measured. The other test technique is a propulsion simulator approach, where a sub-scale, externally powered engine is mounted in the model. This allows proper measurement of inlet/airframe and nozzle/airframe interactions simultaneously. This is Volume 1 of 2: Wind Tunnel Test Pressure Data Report.

  15. The NASA/Industry Design Analysis Methods for Vibrations (DAMVIBS) Program - A government overview. [of rotorcraft technology development using finite element method

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    1992-01-01

    An overview is presented of government contributions to the program called Design Analysis Methods for Vibrations (DAMV) which attempted to develop finite-element-based analyses of rotorcraft vibrations. NASA initiated the program with a finite-element modeling program for the CH-47D tandem-rotor helicopter. The DAMV program emphasized four areas including: airframe finite-element modeling, difficult components studies, coupled rotor-airframe vibrations, and airframe structural optimization. Key accomplishments of the program include industrywide standards for modeling metal and composite airframes, improved industrial designs for vibrations, and the identification of critical structural contributors to airframe vibratory responses. The program also demonstrated the value of incorporating secondary modeling details to improving correlation, and the findings provide the basis for an improved finite-element-based dynamics design-analysis capability.

  16. Overview of the Transport Rotorcraft Airframe Crash Testbed (TRACT) Full Scale Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    The Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate Anthropomorphic Test Devices (ATD) responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 ATDs were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the horizontal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  17. Airframe Repair Specialist, 2-3. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These military-developed curriculum materials consist of five volumes of individualized, self-paced training manuals for use by those studying to be airframe repair technicians. Covered in the individual volumes are the following topics: fundamentals of organization and management (ground safety, aircraft ground safety, and aerospace and power…

  18. Design of a convective cooling system for a Mach 6 hypersonic transport airframe

    NASA Technical Reports Server (NTRS)

    Helenbrook, R. G.; Anthony, F. M.

    1971-01-01

    Results of analytical and design studies are presented for a water-glycol convective cooling system for the airframe structure of a hypersonic transport. System configurations and weights are compared. The influences of system pressure drop and flow control schedules on system weight are defined.

  19. Evaluation of the Second Transport Rotorcraft Airframe Crash Testbed (TRACT 2) Full Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    Two Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the longitudinal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  20. Aviation Maintenance Technology. Airframe. A203. Aircraft Fabric Covering, Painting, and Finishing. Instructor Material.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This teacher's guide is designed to aid teachers in leading students through a module on airframe building and repair, including fabric covering, painting, and finishing. The module contains two units that cover the following topics: (1) inspecting, testing, and installing aircraft fabric coverings and (2) applying dope, paint, and trim. Each unit…

  1. Dual-band infrared imaging to detect corrosion damage within airframes and concrete structures

    NASA Astrophysics Data System (ADS)

    DelGrande, Nancy; Durbin, Philip F.

    1994-03-01

    We are developing dual-band IR (DBIR) imaging and detection techniques to inspect airframes and concrete bridge decks for hidden corrosion damage. Using selective DBIR image ratios, we enhanced surface temperature contrast and removed surface emissivity noise associated with clutter. Our surface temperature maps depicted defect sites, which heat and cool at different rates than their surroundings. Our emissivity-ratio maps tagged and removed the masking effects of surface clutter. For airframe inspections, we used time-resolved DBIR temperature, emissivity-ratio and composite thermal inertia maps to locate corrosion-thinning effects within a flash-heated Boeing 737 airframe. Emissivity-ratio maps tagged and removed clutter sites from uneven paint, dirt and surface markers. Temperature and thermal inertia maps characterized defect sites, types, sizes, thicknesses, thermal properties and material-loss effects from airframe corrosion. For concrete inspections, we mapped DBIR temperature and emissivity-ratio patterns to better interpret surrogate delamination sites within naturally- heated, concrete slabs and removed the clutter mask from sand pile-up, grease stains, rocks and other surface objects.

  2. The Development of Two Composite Energy Absorbers for Use in a Transport Rotorcraft Airframe Crash Testbed (TRACT 2) Full-Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.; Jackson, Karen E.; Annett, Martin S.; Seal, Michael D.; Fasanella, Edwin L.

    2015-01-01

    Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45deg/-45deg/-45deg/+45deg] with respect to the vertical direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction, and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soft soil. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.

  3. Developing and utilizing an Euler computational method for predicting the airframe/propulsion effects for an aft-mounted turboprop transport. Volume 2: User guide

    NASA Technical Reports Server (NTRS)

    Chen, H. C.; Neback, H. E.; Kao, T. J.; Yu, N. Y.; Kusunose, K.

    1991-01-01

    This manual explains how to use an Euler based computational method for predicting the airframe/propulsion integration effects for an aft-mounted turboprop transport. The propeller power effects are simulated by the actuator disk concept. This method consists of global flow field analysis and the embedded flow solution for predicting the detailed flow characteristics in the local vicinity of an aft-mounted propfan engine. The computational procedure includes the use of several computer programs performing four main functions: grid generation, Euler solution, grid embedding, and streamline tracing. This user's guide provides information for these programs, including input data preparations with sample input decks, output descriptions, and sample Unix scripts for program execution in the UNICOS environment.

  4. Subscale, hydrogen-burning, airframe-integrated-scramjet: Experimental and theoretical evaluation of a water cooled strut airframe-integrated-scramjet: Experimental leading edge

    NASA Technical Reports Server (NTRS)

    Pinckney, S. Z.; Guy, R. W.; Beach, H. L., Jr.; Rogers, R. C.

    1975-01-01

    A water-cooled leading-edge design for an engine/airframe integrated scramjet model strut leading edge was evaluated. The cooling design employs a copper cooling tube brazed just downstream of the leading edge of a wedge-shaped strut which is constructed of oxygen-free copper. The survival of the strut leading edge during a series of tests at stagnation point heating rates confirms the practicality of the cooling design. A finite difference thermal model of the strut was also proven valid by the reasonable agreement of calculated and measured values of surface temperature and cooling-water heat transfer.

  5. Integral Airframe Structures (IAS): Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs

    NASA Technical Reports Server (NTRS)

    Munroe, J.; Wilkins, K.; Gruber, M.; Domack, Marcia S. (Technical Monitor)

    2000-01-01

    The Integral Airframe Structures (IAS) program investigated the feasibility of using "integrally stiffened" construction for commercial transport fuselage structure. The objective of the program was to demonstrate structural performance and weight equal to current "built-up" structure with lower manufacturing cost. Testing evaluated mechanical properties, structural details, joint performance, repair, static compression, and two-bay crack residual strength panels. Alloys evaluated included 7050-T7451 plate, 7050-T74511 extrusion, 6013-T6511x extrusion, and 7475-T7351 plate. Structural performance was evaluated with a large 7475-T7351 pressure test that included the arrest of a two-bay longitudinal crack, and a measure of residual strength for a two-bay crack centered on a broken frame. Analysis predictions for the two-bay longitudinal crack panel correlated well with the test results. Analysis activity conducted by the IAS team strongly indicates that current analysis tools predict integral structural behavior as accurately as built-up structure. The cost study results indicated that, compared to built-up fabrication methods, high-speed machining structure from aluminum plate would yield a recurring cost savings of 61%. Part count dropped from 78 individual parts on a baseline panel to just 7 parts for machined IAS structure.

  6. Use of system identification techniques for improving airframe finite element models using test data

    NASA Technical Reports Server (NTRS)

    Hanagud, Sathya V.; Zhou, Weiyu; Craig, James I.; Weston, Neil J.

    1991-01-01

    A method for using system identification techniques to improve airframe finite element models was developed and demonstrated. The method uses linear sensitivity matrices to relate changes in selected physical parameters to changes in total system matrices. The values for these physical parameters were determined using constrained optimization with singular value decomposition. The method was confirmed using both simple and complex finite element models for which pseudo-experimental data was synthesized directly from the finite element model. The method was then applied to a real airframe model which incorporated all the complexities and details of a large finite element model and for which extensive test data was available. The method was shown to work, and the differences between the identified model and the measured results were considered satisfactory.

  7. Use of system identification techniques for improving airframe finite element models using test data

    NASA Technical Reports Server (NTRS)

    Hanagud, Sathya V.; Zhou, Weiyu; Craig, James I.; Weston, Neil J.

    1993-01-01

    A method for using system identification techniques to improve airframe finite element models using test data was developed and demonstrated. The method uses linear sensitivity matrices to relate changes in selected physical parameters to changes in the total system matrices. The values for these physical parameters were determined using constrained optimization with singular value decomposition. The method was confirmed using both simple and complex finite element models for which pseudo-experimental data was synthesized directly from the finite element model. The method was then applied to a real airframe model which incorporated all of the complexities and details of a large finite element model and for which extensive test data was available. The method was shown to work, and the differences between the identified model and the measured results were considered satisfactory.

  8. CFD Assessment of Aerodynamic Degradation of a Subsonic Transport Due to Airframe Damage

    NASA Technical Reports Server (NTRS)

    Frink, Neal T.; Pirzadeh, Shahyar Z.; Atkins, Harold L.; Viken, Sally A.; Morrison, Joseph H.

    2010-01-01

    A computational study is presented to assess the utility of two NASA unstructured Navier-Stokes flow solvers for capturing the degradation in static stability and aerodynamic performance of a NASA General Transport Model (GTM) due to airframe damage. The approach is to correlate computational results with a substantial subset of experimental data for the GTM undergoing progressive losses to the wing, vertical tail, and horizontal tail components. The ultimate goal is to advance the probability of inserting computational data into the creation of advanced flight simulation models of damaged subsonic aircraft in order to improve pilot training. Results presented in this paper demonstrate good correlations with slope-derived quantities, such as pitch static margin and static directional stability, and incremental rolling moment due to wing damage. This study further demonstrates that high fidelity Navier-Stokes flow solvers could augment flight simulation models with additional aerodynamic data for various airframe damage scenarios.

  9. Hypersonic airframe structures: Technology needs and flight test requirements

    NASA Technical Reports Server (NTRS)

    Stone, J. E.; Koch, L. C.

    1979-01-01

    Hypersonic vehicles, that may be produced by the year 2000, were identified. Candidate thermal/structural concepts that merit consideration for these vehicles were described. The current status of analytical methods, materials, manufacturing techniques, and conceptual developments pertaining to these concepts were reviewed. Guidelines establishing meaningful technology goals were defined and twenty-eight specific technology needs were identified. The extent to which these technology needs can be satisfied, using existing capabilities and facilities without the benefit of a hypersonic research aircraft, was assessed. The role that a research aircraft can fill in advancing this technology was discussed and a flight test program was outlined. Research aircraft thermal/structural design philosophy was also discussed. Programs, integrating technology advancements with the projected vehicle needs, were presented. Program options were provided to reflect various scheduling and cost possibilities.

  10. The Engineering Design of Engine/Airframe Integration for the SAENGER Fully Reusable Space Transportation System

    DTIC Science & Technology

    2010-09-01

    propellant rocket engine 26. Parachute container 31. RAMJET nitrogen cooling system storage tank 32. RAMJET control unit 33. High- pressure helium bottle...33. High- pressure helium bottle 34. RAMJET and its service lines fairing 35. Thermal-insulated LH2 tank 36. Studied RAMJET module 37. RAMJE fuel...operational modes and the results of the engine/airframe integration. Major experimental (EFD) and computational ( CFD ) results from the detailed intake

  11. Static and Dynamic Friction Behavior of Candidate High Temperature Airframe Seal Materials

    NASA Technical Reports Server (NTRS)

    Dellacorte, C.; Lukaszewicz, V.; Morris, D. E.; Steinetz, B. M.

    1994-01-01

    The following report describes a series of research tests to evaluate candidate high temperature materials for static to moderately dynamic hypersonic airframe seals. Pin-on-disk reciprocating sliding tests were conducted from 25 to 843 C in air and hydrogen containing inert atmospheres. Friction, both dynamic and static, was monitored and serves as the primary test measurement. In general, soft coatings lead to excessive static friction and temperature affected friction in air environments only.

  12. Studies on Long Term Durability of Aluminum Airframe Structure Made by Affordable Process

    DTIC Science & Technology

    2000-04-01

    New Metallic Materials for the Structure of Aging Aircraft [les Nouveaux Materiaux metalliques pour les structures des aeronefs d’ancienne generation...good resistance to fatigue crack growth. But it also has some problems in formability and the S1. INTRODUCTION corrosion resistance . 6000 series...airframe structural material. Development of properties like corrosion resistance , formability, lower density composites increases its speed now, and

  13. A NASTRAN Vibration Model of the AH-1G Helicopter Airframe. Volume 1

    DTIC Science & Technology

    1974-06-01

    ACCESSION NO 3. RECIPIENT’S CATALOG NUMBER 4. TITLE fand Sub(ltl*> A NASTRAN VIBRATION "lODEL OF TUE AU-IG HELICOPTER AIRFRAME VOLUIE I OF TVJO...Half Drive Snaft (AN 30051) = 1.55 lb - Transmitter Dual Tachometer (AN 3<.Ü54) = 0.80 lb Total Engine Weight = 585.35 ib 4-2

  14. Aerothermodynamic flow phenomena of the airframe-integrated supersonic combustion ramjet

    NASA Technical Reports Server (NTRS)

    Walton, James T.

    1992-01-01

    The unique component flow phenomena is discussed of the airframe-integrated supersonic combustion ramjet (scramjet) in a format geared towards new players in the arena of hypersonic propulsion. After giving an overview of the scramjet aerothermodynamic cycle, the characteristics are then covered individually of the vehicle forebody, inlet, combustor, and vehicle afterbody/nozzle. Attention is given to phenomena such as inlet speeding, inlet starting, inlet spillage, fuel injection, thermal choking, and combustor-inlet interaction.

  15. Development and application of a technique for reducing airframe finite element models for dynamics analysis

    NASA Technical Reports Server (NTRS)

    Hashemi-Kia, Mostafa; Toossi, Mostafa

    1990-01-01

    A computational procedure for the reduction of large finite element models was developed. This procedure is used to obtain a significantly reduced model while retaining the essential global dynamic characteristics of the full-size model. This reduction procedure is applied to the airframe finite element model of AH-64A Attack Helicopter. The resulting reduced model is then validated by application to a vibration reduction study.

  16. Supersonic Cruise Research 1979, part 2. [airframe structures and materials, systems integration, economic analysis

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Advances in airframe structure and materials technology for supersonic cruise aircraft are reported with emphasis on titanium and composite structures. The operation of the Concorde is examined as a baseline for projections into the future. A market survey of U.S. passenger attitudes and preferences, the impact of advanced air transport technology and the integration of systems for the advanced SST and for a smaller research/business jet vehicle are also discussed.

  17. Aircraft Airframe Cost Estimating Relationships. Study Approach and Conclusions

    DTIC Science & Technology

    1987-12-01

    e.g., tighter, bomber/transport, and attack aircraft) is examined. Addi- tionally, for the fighter subsample, the possible benefit of incorporating an...technology index itself, another benefit of the technology study to this analysis was the identification of several individual explanatory variables which...aircraft type benefit the current program? (e.g., Does recent experience with attack aircraft help fighter development? Does recent experience with

  18. Reduced complexity structural modeling for automated airframe synthesis

    NASA Technical Reports Server (NTRS)

    Hajela, Prabhat

    1987-01-01

    A procedure is developed for the optimum sizing of wing structures based on representing the built-up finite element assembly of the structure by equivalent beam models. The reduced-order beam models are computationally less demanding in an optimum design environment which dictates repetitive analysis of several trial designs. The design procedure is implemented in a computer program requiring geometry and loading information to create the wing finite element model and its equivalent beam model, and providing a rapid estimate of the optimum weight obtained from a fully stressed design approach applied to the beam. The synthesis procedure is demonstrated for representative conventional-cantilever and joined wing configurations.

  19. Propulsion-airframe integration for commercial and military aircraft

    NASA Technical Reports Server (NTRS)

    Henderson, William P.

    1988-01-01

    A significant level of research is ongoing at NASA's Langley Research Center on integrating the propulsion system with the aircraft. This program has included nacelle/pylon/wing integration for turbofan transports, propeller/nacelle/wing integration for turboprop transports, and nozzle/afterbody/empennage integration for high performance aircraft. The studies included in this paper focus more specifically on pylon shaping and nacelle location studies for turbofan transports, nacelle and wing contouring and propeller location effects for turboprop transports, and nozzle shaping and empennage effects for high performance aircraft. The studies were primarily conducted in NASA Langley's 16-Foot Transonic Tunnel at Mach numbers up to 1.20. Some higher Mach number data obtained at NASA's Lewis Research Center is also included.

  20. Computational Analysis of a Chevron Nozzle Uniquely Tailored for Propulsion Airframe Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Massey, Steven J.; Elmiligui, Alaa A.; Hunter, Craig A.; Thomas, Russell H.; Pao, S. Paul; Mengle, Vinod G.

    2006-01-01

    A computational flow field and predicted jet noise source analysis is presented for asymmetrical fan chevrons on a modern separate flow nozzle at take off conditions. The propulsion airframe aeroacoustic asymmetric fan nozzle is designed with an azimuthally varying chevron pattern with longer chevrons close to the pylon. A baseline round nozzle without chevrons and a reference nozzle with azimuthally uniform chevrons are also studied. The intent of the asymmetric fan chevron nozzle was to improve the noise reduction potential by creating a favorable propulsion airframe aeroacoustic interaction effect between the pylon and chevron nozzle. This favorable interaction and improved noise reduction was observed in model scale tests and flight test data and has been reported in other studies. The goal of this study was to identify the fundamental flow and noise source mechanisms. The flow simulation uses the asymptotically steady, compressible Reynolds averaged Navier-Stokes equations on a structured grid. Flow computations are performed using the parallel, multi-block, structured grid code PAB3D. Local noise sources were mapped and integrated computationally using the Jet3D code based upon the Lighthill Acoustic Analogy with anisotropic Reynolds stress modeling. In this study, trends of noise reduction were correctly predicted. Jet3D was also utilized to produce noise source maps that were then correlated to local flow features. The flow studies show that asymmetry of the longer fan chevrons near the pylon work to reduce the strength of the secondary flow induced by the pylon itself, such that the asymmetric merging of the fan and core shear layers is significantly delayed. The effect is to reduce the peak turbulence kinetic energy and shift it downstream, reducing overall noise production. This combined flow and noise prediction approach has yielded considerable understanding of the physics of a fan chevron nozzle designed to include propulsion airframe aeroacoustic

  1. Characterization of Flap Edge Noise Radiation from a High-Fidelity Airframe Model

    NASA Technical Reports Server (NTRS)

    Humphreys, William M., Jr.; Khorrami, Mehdi R.; Lockhard, David P.; Neuhart, Dan H.; Bahr, Christopher J.

    2015-01-01

    The results of an experimental study of the noise generated by a baseline high-fidelity airframe model are presented. The test campaign was conducted in the open-jet test section of the NASA Langley 14- by 22-foot Subsonic Tunnel on an 18%-scale, semi-span Gulfstream airframe model incorporating a trailing edge flap and main landing gear. Unsteady surface pressure measurements were obtained from a series of sensors positioned along the two flap edges, and far field acoustic measurements were obtained using a 97-microphone phased array that viewed the pressure side of the airframe. The DAMAS array deconvolution method was employed to determine the locations and strengths of relevant noise sources in the vicinity of the flap edges and the landing gear. A Coherent Output Power (COP) spectral method was used to couple the unsteady surface pressures measured along the flap edges with the phased array output. The results indicate that outboard flap edge noise is dominated by the flap bulb seal cavity with very strong COP coherence over an approximate model-scale frequency range of 1 to 5 kHz observed between the array output and those unsteady pressure sensors nearest the aft end of the cavity. An examination of experimental COP spectra for the inboard flap proved inconclusive, most likely due to a combination of coherence loss caused by decorrelation of acoustic waves propagating through the thick wind tunnel shear layer and contamination of the spectra by tunnel background noise at lower frequencies. Directivity measurements obtained from integration of DAMAS pressure-squared values over defined geometric zones around the model show that the baseline flap and landing gear are only moderately directional as a function of polar emission angle.

  2. Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Sowers, T Shane; Liu, Yuan; Owen, A. Karl; Guo, Ten-Huei

    2015-01-01

    The National Aeronautics and Space Administration (NASA) has developed independent airframe and engine models that have been integrated into a single real-time aircraft simulation for piloted evaluation of propulsion control algorithms. In order to have confidence in the results of these evaluations, the integrated simulation must be validated to demonstrate that its behavior is realistic and that it meets the appropriate Federal Aviation Administration (FAA) certification requirements for aircraft. The paper describes the test procedures and results, demonstrating that the integrated simulation generally meets the FAA requirements and is thus a valid testbed for evaluation of propulsion control modes.

  3. AH-1G flight vibration correlation using NASTRAN and the C81 rotor/airframe coupled analysis

    NASA Technical Reports Server (NTRS)

    Dompka, R. V.; Corrigan, J. J.

    1986-01-01

    Analytical results are presented bearing on the accuracy of state-of-the-art NASTRAN FEM modeling techniques and rotor/airframe coupling methods for the prediction of flight vibrations; these results have been studied by NASA and industry experts in order to ensure scientific control of the analysis/correlation exercise. The rotor loads predicted by the dynamically coupled rotor/airframe analysis showed good agreement between calculated and experimental blade loads, as did the predominant excitation frequency vibration levels predicted by NASTRAN.

  4. Investigation of contact acoustic nonlinearities on metal and composite airframe structures via intensity based health monitoring.

    PubMed

    Romano, P Q; Conlon, S C; Smith, E C

    2013-01-01

    Nonlinear structural intensity (NSI) and nonlinear structural surface intensity (NSSI) based damage detection techniques were improved and extended to metal and composite airframe structures. In this study, the measurement of NSI maps at sub-harmonic frequencies was completed to provide enhanced understanding of the energy flow characteristics associated with the damage induced contact acoustic nonlinearity mechanism. Important results include NSI source localization visualization at ultra-subharmonic (nf/2) frequencies, and damage detection results utilizing structural surface intensity in the nonlinear domain. A detection metric relying on modulated wave spectroscopy was developed and implemented using the NSSI feature. The data fusion of the intensity formulation provided a distinct advantage, as both the single interrogation frequency NSSI and its modulated wave extension (NSSI-MW) exhibited considerably higher sensitivities to damage than using single-sensor (strain or acceleration) nonlinear detection metrics. The active intensity based techniques were also extended to composite materials, and results show both NSSI and NSSI-MW can be used to detect damage in the bond line of an integrally stiffened composite plate structure with high sensitivity. Initial damage detection measurements made on an OH-58 tailboom (Penn State Applied Research Laboratory, State College, PA) indicate the techniques can be transitioned to complex airframe structures achieving high detection sensitivities with minimal sensors and actuators.

  5. Computational Aeroelastic Modeling of Airframes and TurboMachinery: Progress and Challenges

    NASA Technical Reports Server (NTRS)

    Bartels, R. E.; Sayma, A. I.

    2006-01-01

    Computational analyses such as computational fluid dynamics and computational structural dynamics have made major advances toward maturity as engineering tools. Computational aeroelasticity is the integration of these disciplines. As computational aeroelasticity matures it too finds an increasing role in the design and analysis of aerospace vehicles. This paper presents a survey of the current state of computational aeroelasticity with a discussion of recent research, success and continuing challenges in its progressive integration into multidisciplinary aerospace design. This paper approaches computational aeroelasticity from the perspective of the two main areas of application: airframe and turbomachinery design. An overview will be presented of the different prediction methods used for each field of application. Differing levels of nonlinear modeling will be discussed with insight into accuracy versus complexity and computational requirements. Subjects will include current advanced methods (linear and nonlinear), nonlinear flow models, use of order reduction techniques and future trends in incorporating structural nonlinearity. Examples in which computational aeroelasticity is currently being integrated into the design of airframes and turbomachinery will be presented.

  6. A Comparison of Ffowcs Williams-Hawkings Solvers for Airframe Noise Applications

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2002-01-01

    This paper presents a comparison between two implementations of the Ffowcs Williams and Hawkings equation for airframe noise applications. Airframe systems are generally moving at constant speed and not rotating, so these conditions are used in the current investigation. Efficient and easily implemented forms of the equations applicable to subsonic, rectilinear motion of all acoustic sources are used. The assumptions allow the derivation of a simple form of the equations in the frequency-domain, and the time-domain method uses the restrictions on the motion to reduce the work required to find the emission time. The comparison between the frequency domain method and the retarded time formulation reveals some of the advantages of the different approaches. Both methods are still capable of predicting the far-field noise from nonlinear near-field flow quantities. Because of the large input data sets and potentially large numbers of observer positions of interest in three-dimensional problems, both codes utilize the message passing interface to divide the problem among different processors. Example problems are used to demonstrate the usefulness and efficiency of the two schemes.

  7. Propulsion and airframe aerodynamic interactions of supersonic V/STOL configurations. Volume 2: Wind tunnel test force and moment data report

    NASA Technical Reports Server (NTRS)

    Zilz, D. E.

    1985-01-01

    A wind tunnel model of a supersonic V/STOL fighter configuration has been tested to measure the aerodynamic interaction effects which can result from geometrically close-coupled propulsion system/airframe components. The approach was to configure the model to represent two different test techniques. One was a conventional test technique composed of two test modes. In the Flow-Through mode, absolute configuration aerodynamics are measured, including inlet/airframe interactions. In the Jet-Effects mode, incremental nozzle/airframe interactions are measured. The other test technique is a propulsion simulator approach, where a sub-scale, externally powered engine is mounted in the model. This allows proper measurement of inlet/airframe and nozzle/airframe interactions simultaneously. This is Volume 2 of 2: Wind Tunnel Test Force and Moment Data Report.

  8. YF-12 cooperative airframe/propulsion control system program, volume 1

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.; Connolly, G. F.; Mauro, F. M.; Reukauf, P. J.; Marks, R. (Editor)

    1980-01-01

    Several YF-12C airplane analog control systems were converted to a digital system. Included were the air data computer, autopilot, inlet control system, and autothrottle systems. This conversion was performed to allow assessment of digital technology applications to supersonic cruise aircraft. The digital system was composed of a digital computer and specialized interface unit. A large scale mathematical simulation of the airplane was used for integration testing and software checkout.

  9. Survivable, Affordable, Repairable Airframe Program (SARAP) and the Helicopter Kinematic Design Criteria for Crashworthiness. Revision A

    DTIC Science & Technology

    2005-02-18

    associated with the same case number. Even though Access has a utility to export data to Microsoft Excel (which is a spreadsheet), it was still... Excel workbook and a worksheet name. TD-04049 Rev. A Page 12 0.0 50.0 100.0 150.0 200.0 250.0 300.0 0% 20% 40% 60% 80% 100% Cumulative...transformation matrix. The multiplication of this transformation matrix was expressed as operations in three MS Excel worksheet cells. Although no lateral

  10. Synergistic Airframe-Propulsion Interactions and Integrations: A White Paper Prepared by the 1996-1997 Langley Aeronautics Technical Committee

    NASA Technical Reports Server (NTRS)

    Yaros, Steven F.; Sexstone, Matthew G.; Huebner, Lawrence D.; Lamar, John E.; McKinley, Robert E., Jr.; Torres, Abel O.; Burley, Casey L.; Scott, Robert C.; Small, William J.

    1998-01-01

    This white paper addresses the subject of Synergistic Airframe-Propulsion interactions and integrations (SnAPII). The benefits of SnAPII have not been as extensively explored. This is due primarily to the separateness of design process for airframes and propulsion systems, with only unfavorable interactions addressed. The question 'How to design these two systems in such a way that the airframe needs the propulsion and the propulsion needs the airframe?' is the fundamental issue addressed in this paper. Successful solutions to this issue depend on appropriate technology ideas. This paper first details some ten technologies that have yet to make it to commercial products (with limited exceptions) and that could be utilized in a synergistic manner. Then these technologies, either alone or in combination, are applied to both a conventional twin-engine transonic transport and to an unconventional transport, the Blended Wing Body. Lastly, combinations of these technologies are applied to configuration concepts to assess the possibilities of success relative to five of the ten NASA aeronautics goals. These assessments are subjective, but they point the way in which the applied technologies could work together for some break-through benefits.

  11. Propulsion Airframe Aeroacoustic Integration Effects for a Hybrid Wing Body Aircraft Configuration

    NASA Technical Reports Server (NTRS)

    Czech, Michael J.; Thomas, Russell H; Elkoby, Ronen

    2012-01-01

    An extensive experimental investigation was performed to study the propulsion airframe aeroacoustic effects of a high bypass ratio engine for a hybrid wing body aircraft configuration where the engine is installed above the wing. The objective was to provide an understanding of the jet noise shielding effectiveness as a function of engine gas condition and location as well as nozzle configuration. A 4.7% scale nozzle of a bypass ratio seven engine was run at characteristic cycle points under static and forward flight conditions. The effect of the pylon and its orientation on jet noise was also studied as a function of bypass ratio and cycle condition. The addition of a pylon yielded significant spectral changes lowering jet noise by up to 4 dB at high polar angles and increasing it by 2 to 3 dB at forward angles. In order to assess jet noise shielding, a planform representation of the airframe model, also at 4.7% scale was traversed such that the jet nozzle was positioned from downstream of to several diameters upstream of the airframe model trailing edge. Installations at two fan diameters upstream of the wing trailing edge provided only limited shielding in the forward arc at high frequencies for both the axisymmetric and a conventional round nozzle with pylon. This was consistent with phased array measurements suggesting that the high frequency sources are predominantly located near the nozzle exit and, consequently, are amenable to shielding. The mid to low frequency sources were observed further downstream and shielding was insignificant. Chevrons were designed and used to impact the distribution of sources with the more aggressive design showing a significant upstream migration of the sources in the mid frequency range. Furthermore, the chevrons reduced the low frequency source levels and the typical high frequency increase due to the application of chevron nozzles was successfully shielded. The pylon was further modified with a technology that injects air

  12. Propulsion Airframe Integration Test Techniques for Hypersonic Airbreathing Configurations at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Witte, David W.; Huebner, Lawrence D.; Trexler, Carl A.; Cabell, Karen F.; Andrews, Earl H., Jr.

    2003-01-01

    The scope and significance of propulsion airframe integration (PAI) for hypersonic airbreathing vehicles is presented through a discussion of the PAI test techniques utilized at NASA Langley Research Center. Four primary types of PAI model tests utilized at NASA Langley for hypersonic airbreathing vehicles are discussed. The four types of PAI test models examined are the forebody/inlet test model, the partial-width/truncated propulsion flowpath test model, the powered exhaust simulation test model, and the full-length/width propulsion flowpath test model. The test technique for each of these four types of PAI test models is described, and the relevant PAI issues addressed by each test technique are illustrated through the presentation of recent PAI test data.

  13. FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance

    NASA Technical Reports Server (NTRS)

    Harris, Charles E. (Editor)

    1994-01-01

    International technical experts in durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The symposium focused on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure, criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and advanced approaches to resist corrosion and environmentally assisted fatigue.

  14. Toward Improved CFD Predictions of Slender Airframe Aerodynamics Using the F-16XL Aircraft (CAWAPI-2)

    NASA Technical Reports Server (NTRS)

    Luckring, James M.; Rizzi, Arthur; Davis, M. Bruce

    2014-01-01

    A coordinated project has been underway to improve CFD predictions of slender airframe aerodynamics. The work is focused on two flow conditions and leverages a unique flight data set obtained with an F-16XL aircraft. These conditions, a low-speed high angleof- attack case and a transonic low angle-of-attack case, were selected from a prior prediction campaign wherein the CFD failed to provide acceptable results. In this paper the background, objectives and approach to the current project are presented. The work embodies predictions from multiple numerical formulations that are contributed from multiple organizations, and the context of this campaign to other multi-code, multiorganizational efforts is included. The relevance of this body of work toward future supersonic commercial transport concepts is also briefly addressed.

  15. Piloted Evaluation of an Integrated Methodology for Propulsion and Airframe Control Design

    NASA Technical Reports Server (NTRS)

    Bright, Michelle M.; Simon, Donald L.; Garg, Sanjay; Mattern, Duane L.; Ranaudo, Richard J.; Odonoghue, Dennis P.

    1994-01-01

    An integrated methodology for propulsion and airframe control has been developed and evaluated for a Short Take-Off Vertical Landing (STOVL) aircraft using a fixed base flight simulator at NASA Lewis Research Center. For this evaluation the flight simulator is configured for transition flight using a STOVL aircraft model, a full nonlinear turbofan engine model, simulated cockpit and displays, and pilot effectors. The paper provides a brief description of the simulation models, the flight simulation environment, the displays and symbology, the integrated control design, and the piloted tasks used for control design evaluation. In the simulation, the pilots successfully completed typical transition phase tasks such as combined constant deceleration with flight path tracking, and constant acceleration wave-off maneuvers. The pilot comments of the integrated system performance and the display symbology are discussed and analyzed to identify potential areas of improvement.

  16. Thermal-structural design study of an airframe-integrated Scramjet

    NASA Technical Reports Server (NTRS)

    Killackey, J. J.; Katinsky, E. A.; Tepper, S.; Vuigner, A. A.

    1978-01-01

    Design concepts are developed and evaluated for a cooled structures assembly for the Scramjet engine, for engine subsystems mass, volume, and operating requirements, and for the aircraft/engine interface. A thermal protection system was defined that makes it possible to attain a life of 100 hours and 1000 cycles. The coolant equivalence ratio at the Mach 10 maximum thermal loading condition is 0.6, indicating a capacity for airframe cooling. The mechanical design is feasible for manufacture using conventional materials. For the cooled structures in a six-module engine, the mass per unit capture area is 12.4 KN/sq m. The total weight of a six-module engine assembly including the fuel system is 14.73 KN.

  17. Fabrication and development of several heat pipe honeycomb sandwich panel concepts. [airframe integrated scramjet engine

    NASA Technical Reports Server (NTRS)

    Tanzer, H. J.

    1982-01-01

    The feasibility of fabricating and processing liquid metal heat pipes in a low mass honeycomb sandwich panel configuration for application on the NASA Langley airframe-integrated Scramjet engine was investigated. A variety of honeycomb panel facesheet and core-ribbon wick concepts was evaluated within constraints dictated by existing manufacturing technology and equipment. The chosen design consists of an all-stainless steel structure, sintered screen facesheets, and two types of core-ribbon; a diffusion bonded wire mesh and a foil-screen composite. Cleaning, fluid charging, processing, and process port sealing techniques were established. The liquid metals potassium, sodium and cesium were used as working fluids. Eleven honeycomb panels 15.24 cm X 15.24 cm X 2.94 cm were delivered to NASA Langley for extensive performance testing and evaluation; nine panels were processed as heat pipes, and two panels were left unprocessed.

  18. Investigation of airframe noise for a large-scale wing model with high-lift devices

    NASA Astrophysics Data System (ADS)

    Kopiev, V. F.; Zaytsev, M. Yu.; Belyaev, I. V.

    2016-01-01

    The acoustic characteristics of a large-scale model of a wing with high-lift devices in the landing configuration have been studied in the DNW-NWB wind tunnel with an anechoic test section. For the first time in domestic practice, data on airframe noise at high Reynolds numbers (1.1-1.8 × 106) have been obtained, which can be used for assessment of wing noise levels in aircraft certification tests. The scaling factor for recalculating the measurement results to natural conditions has been determined from the condition of collapsing the dimensionless noise spectra obtained at various flow velocities. The beamforming technique has been used to obtain localization of noise sources and provide their ranking with respect to intensity. For flap side-edge noise, which is an important noise component, a noise reduction method has been proposed. The efficiency of this method has been confirmed in DNW-NWB experiments.

  19. Development of a SMA-Based, Slat-Gap Filler for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Long, David L.

    2015-01-01

    Noise produced by unsteady flow around aircraft structures, termed airframe noise, is an important source of aircraft noise during the approach and landing phases of flight. Conventional leading-edge-slat devices for high lift on typical transport aircraft are a prominent source of airframe noise. Many concepts for slat noise reduction have been investigated. Slat-cove fillers have emerged as an attractive solution, but they maintain the gap flow, leaving some noise production mechanisms unabated, and thus represent a nonoptimal solution. Drooped-leading-edge (DLE) concepts have been proposed as "optimal" because the gap flow is eliminated. The deployed leading edge device is not distinct and separate from the main wing in DLE concepts and the high-lift performance suffers at high angles of attack (alpha) as a consequence. Elusive high-alpha performance and excessive weight penalty have stymied DLE development. The fact that high-lift performance of DLE systems is only affected at high alpha suggests another concept that simultaneously achieves the high-lift of the baseline airfoil and the noise reduction of DLE concepts. The concept involves utilizing a conventional leading-edge slat device and a deformable structure that is deployed from the leading edge of the main wing and closes the gap between the slat and main wing, termed a slat-gap filler (SGF). The deployable structure consists of a portion of the skin of the main wing and it is driven in conjunction with the slat during deployment and retraction. Benchtop models have been developed to assess the feasibility and to study important parameters. Computational models have assisted in the bench-top model design and provided valuable insight in the parameter space as well as the feasibility.

  20. Reducing Propulsion Airframe Aeroacoustic Interactions with Uniquely Tailored Chevrons. 2; Installed Nozzles

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Elkoby, Ronen; Brusniak, Leon; Thomas, Russ H.

    2006-01-01

    Propulsion airframe aeroacoustic (PAA) interactions arise due to the manner in which an engine is installed on the airframe and lead to an asymmetry in the flow/acoustic environment, for example, for under-the-wing installations due to the pylon, the wing and the high-lift devices. In this work we study how we can affect these PAA interactions to reduce the overall jet-related installed noise by tailoring the chevron shapes on fan and core nozzles in a unique fashion to take advantage of this asymmetry. In part 1 of this trio of papers we introduced the concept of azimuthally varying chevrons (AVC) and showed how some types of AVCs can be more beneficial than the conventional chevrons when tested on "isolated" scaled nozzles inclusive of the pylon effect. In this paper, we continue to study the effect of installing these AVC nozzles under a typical scaled modern wing with high-lift devices placed in a free jet. The noise benefits of these installed nozzles, as well as their installation effects are systematically studied for several fan/core AVC combinations at typical take-off conditions with high bypass ratio. We show, for example, that the top-enhanced mixing T-fan AVC nozzle (with enhanced mixing near the pylon and less mixing away from it) when combined with conventional chevrons on the core nozzle is quieter than conventional chevrons on both nozzles, and hardly produces any high-frequency lift, just as in the isolated case; however, its installed nozzle benefit is less than its isolated nozzle benefit. This suppression of take-off noise benefit under installed conditions, compared to its isolated nozzle benefit, is seen for all other chevron nozzles. We show how these relative noise benefits are related to the relative installation effects of AVCs and baseline nozzles.

  1. Numerical investigation of tandem-cylinder aerodynamic noise and its control with application to airframe noise

    NASA Astrophysics Data System (ADS)

    Eltaweel, Ahmed

    Prediction and reduction of airframe noise are critically important to the development of quieter civil transport aircraft. The key to noise reduction is a full understanding of the underlying noise source mechanisms. In this study, tandem cylinders in cross-flow as an idealization of a complex aircraft landing gear configuration are considered to investigate the noise generation and its reduction by flow control using single dielectric barrier discharge plasma actuators. The flow over tandem cylinders at ReD = 22, 000 with and without plasma actuation is computed using large-eddy simulation. The plasma effect is modeled as a body force obtained from a semi-empirical model. The flow statistics and surface pressure frequency spectra show excellent agreement with previous experimental measurements. For acoustic calculations, a boundary-element method is implemented to solve the convected Lighthill equation. The solution method is validated in a number of benchmark problems including flows over a cylinder, a rod-airfoil configuration, and a sphere. With validated flow field and acoustic solver, acoustic analysis is performed for the tandem-cylinder configuration to extend the experimental results and understand the mechanisms of noise generation and its control. Without flow control, the acoustic field is dominated by the interaction between the downstream cylinder and the upstream wake. Through suppression of vortex shedding from the upstream cylinder, the interaction noise is reduced drastically by the plasma flow control, and the vortex-shedding noise from the downstream cylinder becomes equally important. At a free-stream Mach number of 0.2, the peak sound pressure level is reduced by approximately 16 dB. This suggests the viability of plasma actuation for active control of airframe noise. The numerical investigation is extended to the noise from a realistic landing gear experimental model. Coarse-mesh computations are performed, and preliminary results are

  2. State of the Art in Beta Titanium Alloys for Airframe Applications

    NASA Astrophysics Data System (ADS)

    Cotton, James D.; Briggs, Robert D.; Boyer, Rodney R.; Tamirisakandala, Sesh; Russo, Patrick; Shchetnikov, Nikolay; Fanning, John C.

    2015-06-01

    Beta titanium alloys were recognized as a distinct materials class in the 1950s, and following the introduction of Ti-13V-11Cr-3Al in the early 1960s, intensive research occurred for decades thereafter. By the 1980s, dozens of compositions had been explored and sufficient work had been accomplished to warrant the first major conference in 1983. Metallurgists of the time recognized beta alloys as highly versatile and capable of remarkable property development at much lower component weights than steels, coupled with excellent corrosion resistance. Although alloys such as Ti-15V-3Al-3Sn-3Cr, Ti-10V-2Fe-3Al and Ti-3AI-8V-6Cr-4Mo-4Zr (Beta C) were commercialized into well-known airframe systems by the 1980s, Ti-13V-11Cr-3Al was largely discarded following extensive employment on the SR-71 Blackbird. The 1990s saw the implementation of specialty beta alloys such as Beta 21S and Alloy C, in large part for their chemical and oxidation resistance. It was also predicted that by the 1990s, cost would be the major limitation on expansion into new applications. This turned out to be true and is part of the reason for some stagnation in commercialization of new such compositions over the past two decades, despite a good understanding of the relationships among chemistry, processing, and performance and some very attractive offerings. Since then, only a single additional metastable beta alloy, Ti-5Al-5V-5Mo-3Cr-0.5Fe, has been commercialized in aerospace, although low volumes of other chemistries have found a place in the biomedical implant market. This article examines the evolution of this important class of materials and the current status in airframe applications. It speculates on challenges for expanding their use.

  3. Propulsion Airframe Aeroacoustic Integration Effects for a Hybrid Wing Body Aircraft Configuration

    NASA Technical Reports Server (NTRS)

    Czech, Michael J.; Thomas, Russell H.; Elkoby, Ronen

    2010-01-01

    An extensive experimental investigation was performed to study the propulsion airframe aeroacoustic effects of a high bypass ratio engine for a hybrid wing body aircraft configuration where the engine is installed above the wing. The objective was to provide an understanding of the jet noise shielding effectiveness as a function of engine gas condition and location as well as nozzle configuration. A 4.7% scale nozzle of a bypass ratio seven engine was run at characteristic cycle points under static and forward flight conditions. The effect of the pylon and its orientation on jet noise was also studied as a function of bypass ratio and cycle condition. The addition of a pylon yielded significant spectral changes lowering jet noise by up to 4dB at high polar angles and increasing it by 2 to 3dB at forward angles. In order to assess jet noise shielding, a planform representation of the airframe model, also at 4.7% scale was traversed relative to the jet nozzle from downstream to several diameters upstream of the wing trailing edge. Installations at two fan diameters upstream of the wing trailing edge provided only limited shielding in the forward arc at high frequencies for both the axisymmetric and a conventional round nozzle with pylon. This was consistent with phased array measurements suggesting that the high frequency sources are predominantly located near the nozzle exit and, consequently, are amenable to shielding. The mid to low frequencies sources were observed further downstream and shielding was insignificant. Chevrons were designed and used to impact the distribution of sources with the more aggressive design showing a significant upstream migration of the sources in the mid frequency range. Furthermore, the chevrons reduced the low frequency source levels and the typical high frequency increase due to the application of chevron nozzles was successfully shielded. The pylon was further modified with a technology that injects air through the shelf of the

  4. Hybrid Wing Body Aircraft System Noise Assessment with Propulsion Airframe Aeroacoustic Experiments

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Burley, Casey L.; Olson, Erik D.

    2010-01-01

    A system noise assessment of a hybrid wing body configuration was performed using NASA s best available aircraft models, engine model, and system noise assessment method. A propulsion airframe aeroacoustic effects experimental database for key noise sources and interaction effects was used to provide data directly in the noise assessment where prediction methods are inadequate. NASA engine and aircraft system models were created to define the hybrid wing body aircraft concept as a twin engine aircraft with a 7500 nautical mile mission. The engines were modeled as existing technology high bypass ratio turbofans. The baseline hybrid wing body aircraft was assessed at 22 dB cumulative below the FAA Stage 4 certification level. To determine the potential for noise reduction with relatively near term technologies, seven other configurations were assessed beginning with moving the engines two fan nozzle diameters upstream of the trailing edge and then adding technologies for reduction of the highest noise sources. Aft radiated noise was expected to be the most challenging to reduce and, therefore, the experimental database focused on jet nozzle and pylon configurations that could reduce jet noise through a combination of source reduction and shielding effectiveness. The best configuration for reduction of jet noise used state-of-the-art technology chevrons with a pylon above the engine in the crown position. This configuration resulted in jet source noise reduction, favorable azimuthal directivity, and noise source relocation upstream where it is more effectively shielded by the limited airframe surface, and additional fan noise attenuation from acoustic liner on the crown pylon internal surfaces. Vertical and elevon surfaces were also assessed to add shielding area. The elevon deflection above the trailing edge showed some small additional noise reduction whereas vertical surfaces resulted in a slight noise increase. With the effects of the configurations from the

  5. Airframe RDT&E Cost Estimating: A Justification for and Development of Unique Cost Estimating Relationships According to Aircraft Type.

    DTIC Science & Technology

    1982-09-01

    T1I4 PAGO(ftWg, Dle& Bnt e 0 ’-Airframe RDT&E costs are invariably predicted by utilizing one general cost estimatin relationship (CER) regardless of...and in funding decisions demanding reliable , internally consistent estimates of absolute cost (10:1). Cost estimating capability is only as accurate as...pertaining to the RDT&E phase appear to be limited in their ability to accurately predict weapon system development costs. This thesis focuses on a

  6. Calculation of the three-dimension, supersonic, inviscid, steady flow past an arrow-winged airframe, part 1

    NASA Technical Reports Server (NTRS)

    Moretti, G.

    1976-01-01

    A detailed description of the procedure used to compute three dimensional, supersonic, inviscid, steady flows past airframes is given. No limitations are imposed on the geometry of the airplane. Suitable computational grids are generated by automatic conformal mappings. The equations of motion, with pressure, entropy, and velocity direction as basic unknowns, are written and discretized in the computational space. Special rules to approximate derivatives are given. Boundary points are treated by a modified method of characteristics.

  7. Future technology aim of the National Aerospace Plane Program

    NASA Technical Reports Server (NTRS)

    Anderson, Charles W.

    1993-01-01

    Technical areas where hypersonic technology programs outside NASP might offer assistance and participate in the NASP program are considered. These specific areas include airframe, technology opportunities for providing better performance and reduced weight, the NDV application of NASP technology, and engine propellant systems and subsystems.

  8. Passive impact localisation for the structural health monitoring of new airframe materials

    NASA Astrophysics Data System (ADS)

    Ward, Jacob; Croxford, Anthony; Paget, Christophe

    2013-08-01

    This experimental work considers the use of permanently attached sensors for the detection and location of impacts to a carbon fibre reinforced plastic panel with stringers. Deterministic knowledge of the propagation of Lamb waves in the structure is not used. Instead a statistical measure of the signal is used to determine the arrival time of elastic waves propagating in the structure as a result of the impact. A comparison is made between a conventional method and the statistical method. The conventional method, which has been routinely used in industry for acoustic emission imaging, uses the timing of a peak in the recorded signal. The statistical method uses the Rayleigh maximum likelihood estimator. The statistical method is shown to provide both more precise and robust estimates of the elastic wave arrival time. An array of just four sensors is used to locate the impacts. The accuracy of the localisations is used to visualise the effectiveness of the two methods for the low sensor density used. Low sensor density is necessary for minimising system weight and cost. The equivalent net sensor density used in this experiment was five sensors per meter squared. Carbon fibre reinforced plastic is today used for both exterior surfaces and primary structure of airframes entering service. The industrial relevance of this work is to mitigate the diminishing role of visual inspection for evaluating the health of aerospace structures, where impact damage may not be visible.

  9. Life cycle strain monitoring of composite airframe structures by FBG sensors

    NASA Astrophysics Data System (ADS)

    Takahashi, I.; Sekine, K.; Kume, M.; Takeya, H.; Minakuchi, S.; Takeda, N.; Enomoto, K.

    2013-04-01

    Life cycle health monitoring technology for composite airframe structures based on strain mapping is proposed. It detects damages and deformation harmful to the structures by strain mapping using fiber Bragg grating (FBG) sensors through their life cycles including the stages of molding, machining, assembling, operation, and maintenance. In this paper, we firstly carried out a strain monitoring test of CFRP mock-up structure through the life cycle including the stage of molding, machining, assembling, and operation. The experimental result confirms that the strain which arises in each life cycle stage can be measured by FBG sensors embedded in molding stage and demonstrates the feasibility of life cycle structural health monitoring by using FBG sensors. Secondly, we conducted the strain monitoring test of CFRP scarf-repaired specimen subject to fatigue load. FBG sensors were embedded in the scarf-repaired part of the specimen and their reflection spectra were measured in uni-axial cyclic load test. Strain changes were compared with the pulse thermographic inspection. As a result, strain measured by FBG sensors changed sensitively with debonded area of repair patch, which demonstrates that the debondings of repair patches in scarf-repaired composites due to fatigue load can be detected by FBG sensors.

  10. Internal Shock Interactions in Propulsion/Airframe Integrated Three-Dimensional Sidewall Compression Scramjet Inlets

    NASA Technical Reports Server (NTRS)

    Holland, Scott D.; Perkins, John N.

    1992-01-01

    The advantages and design requirements of propulsion/airframe integration for high Mach number flight have led to extensive study of the three-dimensional sidewall compression scramjet inlet in recent years. Recent research publications have indicated testing over a broad range of Mach number (2 to 18) in a variety of test gases, such as air, helium, and tetrafluoromethane. Multiple experimental techniques have been employed to obtain detailed internal shock interaction data, performance data, and inlet starting limits. Computational fluid dynamics has been effectively used for preliminary parametric studies as well as in parallel with experiments to aid in the explanation of unusual or unexpected flow phenomena. Inlets of this genre afford a relatively simple, generic geometry while producing a highly complex, three-dimensional flow field dominated by shock/shock and shock/boundary layer interactions. While the importance of the viscous effects in high speed inlet interactions is recognized, the present work addresses in a parametric fashion the inviscid effects of leading edge sweep, sidewall compression, and inflow Mach number on the internal shock structure in terms of inlet compression and mass capture. In the process, the source of the of the Mach number invariance with leading edge sweep for a constant sidewall compression class of inlet is identified, and a previously undocumented spillage phenomenon in a constant effective wedge angle class of inlets is discussed.

  11. Toward Establishing a Realistic Benchmark for Airframe Noise Research: Issues and Challenges

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.

    2010-01-01

    The availability of realistic benchmark configurations is essential to enable the validation of current Computational Aeroacoustic (CAA) methodologies and to further the development of new ideas and concepts that will foster the technologies of the next generation of CAA tools. The selection of a real-world configuration, the subsequent design and fabrication of an appropriate model for testing, and the acquisition of the necessarily comprehensive aeroacoustic data base are critical steps that demand great care and attention. In this paper, a brief account of the nose landing-gear configuration, being proposed jointly by NASA and the Gulfstream Aerospace Company as an airframe noise benchmark, is provided. The underlying thought processes and the resulting building block steps that were taken during the development of this benchmark case are given. Resolution of critical, yet conflicting issues is discussed - the desire to maintain geometric fidelity versus model modifications required to accommodate instrumentation; balancing model scale size versus Reynolds number effects; and time, cost, and facility availability versus important parameters like surface finish and installation effects. The decisions taken during the experimental phase of a study can significantly affect the ability of a CAA calculation to reproduce the prevalent flow conditions and associated measurements. For the nose landing gear, the most critical of such issues are highlighted and the compromises made to resolve them are discussed. The results of these compromises will be summarized by examining the positive attributes and shortcomings of this particular benchmark case.

  12. What Was Learned in Predicting Slender Airframe Aerodynamics with the F16-XL Aircraft

    NASA Technical Reports Server (NTRS)

    Rizzi, Arthur; Lucking, James M.

    2014-01-01

    The CAWAPI-2 coordinated project has been underway to improve CFD predictions of slender airframe aerodynamics. The work is focused on two flow conditions and leverages a unique flight data set obtained with the F-16XL aircraft for comparison and verification. These conditions, a low-speed high angle-of-attack case and a transonic low angle-of-attack case, were selected from a prior prediction campaign wherein the CFD failed to provide acceptable results. In re-visiting these two cases, approaches for improved results include better, denser grids using more grid adaptation to local flow features as well as unsteady higher-fidelity physical modeling like hybrid RANS/URANS-LES methods. The work embodies predictions from multiple numerical formulations that are contributed from multiple organizations where some authors investigate other possible factors that could explain the discrepancies in agreement, e.g. effects due to deflected control surfaces during the flight tests, as well as static aeroelastic deflection of the outer wing. This paper presents the synthesis of all the results and findings and draws some conclusions that lead to an improved understanding of the underlying flow physics, and finally making the connections between the physics and aircraft features.

  13. An Evaluation of High Temperature Airframe Seals for Advanced Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    DeMange, Jeffrey J.; Dunlap, Patrick H.; Steinetz, Bruce M.; Drlik, Gary J.

    2007-01-01

    High temperature seals are required for advanced hypersonic airframe applications. In this study, both spring tube thermal barriers and innovative wafer seal systems were evaluated under relevant hypersonic test conditions (temperatures, pressures, etc.) via high temperature compression testing and room temperature flow assessments. Thermal barriers composed of a Rene 41 spring tube filled with Saffil insulation and overbraided with a Nextel 312 sheath showed acceptable performance at 1500 F in both short term and longer term compression testing. Nextel 440 thermal barriers with Rene 41 spring tubes and Saffil insulation demonstrated good compression performance up to 1750 F. A silicon nitride wafer seal/compression spring system displayed excellent load performance at temperatures as high as 2200 F and exhibited room temperature leakage values that were only 1/3 those for the spring tube rope seals. For all seal candidates evaluated, no significant degradation in leakage resistance was noted after high temperature compression testing. In addition to these tests, a superalloy seal suitable for dynamic seal applications was optimized through finite element techniques.

  14. Application of an Integrated Methodology for Propulsion and Airframe Control Design to a STOVL Aircraft

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane

    1994-01-01

    An advanced methodology for integrated flight propulsion control (IFPC) design for future aircraft, which will use propulsion system generated forces and moments for enhanced maneuver capabilities, is briefly described. This methodology has the potential to address in a systematic manner the coupling between the airframe and the propulsion subsystems typical of such enhanced maneuverability aircraft. Application of the methodology to a short take-off vertical landing (STOVL) aircraft in the landing approach to hover transition flight phase is presented with brief description of the various steps in the IFPC design methodology. The details of the individual steps have been described in previous publications and the objective of this paper is to focus on how the components of the control system designed at each step integrate into the overall IFPC system. The full nonlinear IFPC system was evaluated extensively in nonreal-time simulations as well as piloted simulations. Results from the nonreal-time evaluations are presented in this paper. Lessons learned from this application study are summarized in terms of areas of potential improvements in the STOVL IFPC design as well as identification of technology development areas to enhance the applicability of the proposed design methodology.

  15. Application of CART3D to Complex Propulsion-Airframe Integration with Vehicle Sketch Pad

    NASA Technical Reports Server (NTRS)

    Hahn, Andrew S.

    2012-01-01

    Vehicle Sketch Pad (VSP) is an easy-to-use modeler used to generate aircraft geometries for use in conceptual design and analysis. It has been used in the past to generate metageometries for aerodynamic analyses ranging from handbook methods to Navier-Stokes computational fluid dynamics (CFD). As desirable as it is to bring high order analyses, such as CFD, into the conceptual design process, this has been difficult and time consuming in practice due to the manual nature of both surface and volume grid generation. Over the last couple of years, VSP has had a major upgrade of its surface triangulation and export capability. This has enhanced its ability to work with Cart3D, an inviscid, three dimensional fluid flow toolset. The combination of VSP and Cart3D allows performing inviscid CFD on complex geometries with relatively high productivity. This paper will illustrate the use of VSP with Cart3D through an example case of a complex propulsion-airframe integration (PAI) of an over-wing nacelle (OWN) airliner configuration.

  16. Turbine Powered Simulator Calibration and Testing for Hybrid Wing Body Powered Airframe Integration

    NASA Technical Reports Server (NTRS)

    Shea, Patrick R.; Flamm, Jeffrey D.; Long, Kurtis R.; James, Kevin D.; Tompkins, Daniel M.; Beyar, Michael D.

    2016-01-01

    Propulsion airframe integration testing on a 5.75% scale hybrid wing body model us- ing turbine powered simulators was completed at the National Full-Scale Aerodynamics Complex 40- by 80-foot test section. Four rear control surface con gurations including a no control surface de ection con guration were tested with the turbine powered simulator units to investigate how the jet exhaust in uenced the control surface performance as re- lated to the resultant forces and moments on the model. Compared to ow-through nacelle testing on the same hybrid wing body model, the control surface e ectiveness was found to increase with the turbine powered simulator units operating. This was true for pitching moment, lift, and drag although pitching moment was the parameter of greatest interest for this project. With the turbine powered simulator units operating, the model pitching moment was seen to increase when compared to the ow-through nacelle con guration indicating that the center elevon and vertical tail control authority increased with the jet exhaust from the turbine powered simulator units.

  17. Flight Test Results for Uniquely Tailored Propulsion-Airframe Aeroacoustic Chevrons: Community Noise

    NASA Technical Reports Server (NTRS)

    Nesbitt, Eric; Mengle, Vinod; Czech, Michael; Callendar, Bryan; Thomas, Russ

    2006-01-01

    The flow/acoustic environment around the jet exhaust of an engine when installed on an airplane, say, under the wing, is highly asymmetric due to the pylon, the wing and the high-lift devices. Recent scale model tests have shown that such Propulsion Airframe Aeroacoustic (PAA) interactions and the jet mixing noise can be reduced more than with conventional azimuthally uniform chevrons by uniquely tailoring the chevrons to produce enhanced mixing near the pylon. This paper describes the community noise results from a flight test on a large twin-engine airplane using this concept of azimuthally varying chevrons for engines installed under the wing. Results for two different nozzle configurations are described: azimuthally varying "PAA T-fan" chevrons on the fan nozzle with a baseline no-chevron core nozzle and a second with PAA T-fan chevrons with conventional azimuthally uniform chevrons on the core nozzle. We analyze these test results in comparison to the baseline no-chevron nozzle on both spectral and integrated power level bases. The study focuses on the peak jet noise reduction and the effects at high frequencies for typical take-off power settings. The noise reduction and the absolute noise levels are then compared to model scale results. The flight test results verify that the PAA T-fan nozzles in combination with standard core chevron nozzles can, indeed, give a reasonable amount of noise reduction at low frequencies without high-frequency lift during take-off conditions and hardly any impact on the cruise thrust coefficient.

  18. Flight Test Results for Uniquely Tailored Propulsion-Airframe Aeroacoustic Chevrons: Shockcell Noise

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Ganz, Ulrich W.; Nesbitt, Eric; Bultemeier, Eric J.; Thomas, Russell H.; Nesbitt, Eric

    2006-01-01

    Azimuthally varying chevrons (AVC) which have been uniquely tailored to account for the asymmetric propulsion-airframe aeroacoustic interactions have recently shown significant reductions in jet-related community noise at low-speed take-off conditions in scale model tests of coaxial nozzles with high bypass ratio. There were indications that such AVCs may also provide shockcell noise reductions at high cruise speeds. This paper describes the flight test results when one such AVC concept, namely, the T-fan chevrons with enhanced mixing near the pylon, was tested at full-scale on a modern large twin-jet aircraft (777-300ER) with focus on shockcell noise at mid-cruise conditions. Shockcell noise is part of the interior cabin noise at cruise conditions and its reduction is useful from the viewpoint of passenger comfort. Noise reduction at the source, in the exhaust jet, especially, at low frequencies, is beneficial from the perspective of reduced fuselage sidewall acoustic lining. Results are shown in terms of unsteady pressure spectra both on the exterior surface of the fuselage at several axial stations and also microphone arrays placed inside the fuselage aft of the engine. The benefits of T-fan chevrons, with and without conventional chevrons on the core nozzle, are shown for several engine operating conditions at cruise involving supersonic fan stream and subsonic or supersonic core stream. The T-fan AVC alone provides up to 5 dB low-frequency noise reduction on the fuselage exterior skin and up to 2 dB reduction inside the cabin. Addition of core chevrons appears to increase the higher frequency noise. This flight test result with the previous model test observation that the T-fan AVCs have hardly any cruise thrust coefficient loss (< 0.05%) make them viable candidates for reducing interior cabin noise in high bypass ratio engines.

  19. New Tools Being Developed for Engine- Airframe Blade-Out Structural Simulations

    NASA Technical Reports Server (NTRS)

    Lawrence, Charles

    2003-01-01

    One of the primary concerns of aircraft structure designers is the accurate simulation of the blade-out event. This is required for the aircraft to pass Federal Aviation Administration (FAA) certification and to ensure that the aircraft is safe for operation. Typically, the most severe blade-out occurs when a first-stage fan blade in a high-bypass gas turbine engine is released. Structural loading results from both the impact of the blade onto the containment ring and the subsequent instantaneous unbalance of the rotating components. Reliable simulations of blade-out are required to ensure structural integrity during flight as well as to guarantee successful blade-out certification testing. The loads generated by these analyses are critical to the design teams for several components of the airplane structures including the engine, nacelle, strut, and wing, as well as the aircraft fuselage. Currently, a collection of simulation tools is used for aircraft structural design. Detailed high-fidelity simulation tools are used to capture the structural loads resulting from blade loss, and then these loads are used as input into an overall system model that includes complete structural models of both the engines and the airframe. The detailed simulation (shown in the figure) includes the time-dependent trajectory of the lost blade and its interactions with the containment structure, and the system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes are typically used, and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine s turbomachinery. To develop and validate these new tools with test data, the NASA Glenn Research Center has teamed with GE Aircraft Engines, Pratt & Whitney, Boeing Commercial Aircraft, Rolls-Royce, and MSC.Software.

  20. Effect of Directional Array Size on the Measurement of Airframe Noise Components

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    1999-01-01

    A study was conducted to examine the effects of overall size of directional (or phased) arrays on the measurement of aeroacoustic components. An airframe model was mounted in the potential core of an open-jet windtunnel, with the directional arrays located outside the flow in an anechoic environment. Two array systems were used; one with a solid measurement angle that encompasses 31.6 deg.of source directivity and a smaller one that encompasses 7.2 deg. The arrays, and sub-arrays of various sizes, measured noise from a calibrator source and flap edge model setups. In these cases, noise was emitted from relatively small, but finite size source regions, with intense levels compared to other sources. Although the larger arrays revealed much more source region detail, the measured source levels were substantially reduced due to finer resolution compared to that of the smaller arrays. To better understand the measurements quantitatively, an analytical model was used to define the basic relationships between array to source region sizes and measured output level. Also, the effect of noise scattering by shear layer turbulence was examined using the present data and those of previous studies. Taken together, the two effects were sufficient to explain spectral level differences between arrays of different sizes. An important result of this study is that total (integrated) noise source levels are retrievable and the levels are independent of the array size as long as certain experimental and processing criteria are met. The criteria for both open and closed tunnels are discussed. The success of special purpose diagonal-removal processing in obtaining integrated results is apparently dependent in part on source distribution. Also discussed is the fact that extended sources are subject to substantial measurement error, especially for large arrays.

  1. Multi-scale mechanism based life prediction of polymer matrix composites for high temperature airframe applications

    NASA Astrophysics Data System (ADS)

    Upadhyaya, Priyank

    A multi-scale mechanism-based life prediction model is developed for high-temperature polymer matrix composites (HTPMC) for high temperature airframe applications. In the first part of this dissertation the effect of Cloisite 20A (C20A) nano-clay compounding on the thermo-oxidative weight loss and the residual stresses due to thermal oxidation for a thermoset polymer bismaleimide (BMI) are investigated. A three-dimensional (3-D) micro-mechanics based finite element analysis (FEA) was conducted to investigate the residual stresses due to thermal oxidation using an in-house FEA code (NOVA-3D). In the second part of this dissertation, a novel numerical-experimental methodology is outlined to determine cohesive stress and damage evolution parameters for pristine as well as isothermally aged (in air) polymer matrix composites. A rate-dependent viscoelastic cohesive layer model was implemented in an in-house FEA code to simulate the delamination initiation and propagation in unidirectional polymer composites before and after aging. Double cantilever beam (DCB) experiments were conducted (at UT-Dallas) on both pristine and isothermally aged IM-7/BMI composite specimens to determine the model parameters. The J-Integral based approach was adapted to extract cohesive stresses near the crack tip. Once the damage parameters had been characterized, the test-bed FEA code employed a micromechanics based viscoelastic cohesive layer model to numerically simulate the DCB experiment. FEA simulation accurately captures the macro-scale behavior (load-displacement history) simultaneously with the micro-scale behavior (crack-growth history).

  2. Calibration of Airframe and Occupant Models for Two Full-Scale Rotorcraft Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Horta, Lucas G.; Polanco, Michael A.

    2012-01-01

    Two full-scale crash tests of an MD-500 helicopter were conducted in 2009 and 2010 at NASA Langley's Landing and Impact Research Facility in support of NASA s Subsonic Rotary Wing Crashworthiness Project. The first crash test was conducted to evaluate the performance of an externally mounted composite deployable energy absorber under combined impact conditions. In the second crash test, the energy absorber was removed to establish baseline loads that are regarded as severe but survivable. Accelerations and kinematic data collected from the crash tests were compared to a system integrated finite element model of the test article. Results from 19 accelerometers placed throughout the airframe were compared to finite element model responses. The model developed for the purposes of predicting acceleration responses from the first crash test was inadequate when evaluating more severe conditions seen in the second crash test. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used to calibrate model results for the second full-scale crash test. This combination of heuristic and quantitative methods was used to identify modeling deficiencies, evaluate parameter importance, and propose required model changes. It is shown that the multi-dimensional calibration techniques presented here are particularly effective in identifying model adequacy. Acceleration results for the calibrated model were compared to test results and the original model results. There was a noticeable improvement in the pilot and co-pilot region, a slight improvement in the occupant model response, and an over-stiffening effect in the passenger region. This approach should be adopted early on, in combination with the building-block approaches that are customarily used, for model development and test planning guidance. Complete crash simulations with validated finite element models can be used

  3. Reducing Propulsion Airframe Aeroacoustic Interactions with Uniquely Tailored Chevrons. 1.; Isolated Nozzles

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Elkroby, Ronen; Brunsniak, Leon; Thomas, Russ H.

    2006-01-01

    The flow/acoustic environment surrounding an engine nozzle installed on an airplane, say, under the wing, is asymmetric due to the pylon, the wing and the interaction of the exhaust jet with flaps on the wing. However, the conventional chevrons, which are azimuthally uniform serrations on the nozzle lip, do not exploit the asymmetry due to these propulsion airframe aeroacoustic interactions to reduce jet noise. In this pioneering study we use this non-axisymmetry to our advantage and examine if the total jet-related noise radiated to the ground can be reduced by using different types of azimuthally varying chevrons (AVC) which vary the mixing around the nozzle periphery. Several scale models of the isolated nozzle, representative of high bypass ratio engine nozzles, were made with a pylon and azimuthally varying chevrons on both fan and core nozzles to enhance mixing at the top (near the pylon) with less mixing at the bottom (away from the pylon) or vice versa. Various combinations of fan and core AVC nozzles were systematically tested at typical take-off conditions inside a free jet wind-tunnel and, here, in Part 1 we analyze the acoustics results for the isolated nozzle with a pylon, with installation effects reported in Parts 2 and 3. Several interesting results are discovered: amongst the fan AVCs the top-enhanced mixing T-fan chevron nozzle is quieter in combination with any core AVC nozzle when compared to conventional chevrons; however, the bottom-mixing B-fan chevrons, as well as the core AVC nozzles, by themselves, are noisier. Further, the low-frequency source strengths in the jet plume, obtained via phased microphone arrays, also corroborate the far field sound, and for the T-fan chevrons such sources move further downstream than those for baseline or conventional chevron nozzles.

  4. Unsteady Flowfield Around Tandem Cylinders as Prototype for Component Interaction in Airframe Noise

    NASA Technical Reports Server (NTRS)

    Khorrami, Meldi R.; Choudhari, Meelan M.; Jenkins, Luther N.; McGinley, Catherine B.

    2005-01-01

    Synergistic application of experiments and numerical simulations is crucial to understanding the underlying physics of airframe noise sources. The current effort is aimed at characterizing the details of the flow interaction between two cylinders in a tandem configuration. This setup is viewed to be representative of several component-level flow interactions that occur when air flows over the main landing gear of large civil transports. Interactions of this type are likely to have a significant impact on the noise radiation associated with the aircraft undercarriage. The paper is focused on two-dimensional, time-accurate flow simulations for the tandem cylinder configuration. Results of the unsteady Reynolds Averaged Navier-Stokes (URANS) computations with a two-equation turbulence model, at a Reynolds number of 0.166 million and a Mach number of 0.166, are presented. The experimental measurements of the same flow field are discussed in a separate paper by Jenkins, Khorrami, Choudhari, and McGinley (2005). Two distinct flow regimes of interest, associated with short and intermediate separation distances between the two cylinders, are considered. Emphasis is placed on understanding both time averaged and unsteady flow features between the two cylinders and in the wake of the rear cylinder. Predicted mean flow quantities and vortex shedding frequencies show reasonable agreement with the measured data for both cylinder spacings. Computations for short separation distance indicate decay of flow unsteadiness with time, which is not unphysical; however, the predicted sensitivity of mean lift coefficient to small angles of attack explains the asymmetric flowfield observed during the experiments.

  5. Developments in amphibian captive breeding and reintroduction programs.

    PubMed

    Harding, Gemma; Griffiths, Richard A; Pavajeau, Lissette

    2016-04-01

    Captive breeding and reintroduction remain high profile but controversial conservation interventions. It is important to understand how such programs develop and respond to strategic conservation initiatives. We analyzed the contribution to conservation made by amphibian captive breeding and reintroduction since the launch of the International Union for Conservation of Nature (IUCN) Amphibian Conservation Action Plan (ACAP) in 2007. We assembled data on amphibian captive breeding and reintroduction from a variety of sources including the Amphibian Ark database and the IUCN Red List. We also carried out systematic searches of Web of Science, JSTOR, and Google Scholar for relevant literature. Relative to data collected from 1966 to 2006, the number of species involved in captive breeding and reintroduction projects increased by 57% in the 7 years since release of the ACAP. However, there have been relatively few new reintroductions over this period; most programs have focused on securing captive-assurance populations (i.e., species taken into captivity as a precaution against extinctions in the wild) and conservation-related research. There has been a shift to a broader representation of frogs, salamanders, and caecilians within programs and an increasing emphasis on threatened species. There has been a relative increase of species in programs from Central and South America and the Caribbean, where amphibian biodiversity is high. About half of the programs involve zoos and aquaria with a similar proportion represented in specialist facilities run by governmental or nongovernmental agencies. Despite successful reintroduction often being regarded as the ultimate milestone for such programs, the irreversibility of many current threats to amphibians may make this an impractical goal. Instead, research on captive assurance populations may be needed to develop imaginative solutions to enable amphibians to survive alongside current, emerging, and future threats.

  6. Experimental Results of the 2.7% Reference H Nacelle Airframe Interference High Speed Civil Transport Model

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina

    1999-01-01

    Experiments were conducted in the NASA Ames 9-Ft by 7-Ft Supersonic and 11-Ft by 11-Ft Transonic Wind Tunnels of a 2.7% Reference H (Ref. H) Nacelle Airframe Interference (NAI) High Speed Civil Transport (HSCT) model. NASA Ames did the experiment with the cooperation and assistance of Boeing and McDonnell Douglas. The Ref. H geometry was designed by Boeing. The model was built and tested by NASA under a license agreement with Boeing. Detailed forces and pressures of individual components of the configuration were obtained to assess nacelle airframe interference through the transonic and supersonic flight regime. The test apparatus was capable of measuring forces and pressures of the Wing body (WB) and nacelles. Axisymmetric and 2-D inlet nacelles were tested with the WB in both the in-proximity and captive mode. The in-proximity nacelles were mounted to a nacelle support system apparatus and were individually positioned. The right hand nacelles were force instrumented with flow through strain-gauged balances and the left hand nacelles were pressure instrumented. Mass flow ratio was varied to get steady state inlet unstart data. In addition, supersonic spillage data was taken by testing the 2-D inlet nacelles with ramps and the axisymmetric inlet nacelles with an inlet centerbody for the Mach condition of interest. The captive nacelles, both axisymmetric and 2-D, were attached to the WB via diverters. The captive 2-D inlet nacelle was also tested with ramps to get supersonic spillage data. Boeing analyzed the data and showed a drag penalty of four drag counts for the 2-D compared with the axisymmetric inlet nacelle. Two of the four counts were attributable to the external bevel designed into the 2-D inlet contour. Boeing and McDonnell Douglas used these data for evaluating Computational Fluid Dynamic (CFD) codes and for evaluation of nacelle airframe integration problems and solutions.

  7. Bibliography on aerodynamics of airframe/engine integration of high-speed turbine-powered aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Nichols, M. R.

    1980-01-01

    This bibliography was developed as a first step in the preparation of a monograph on the subject of the aerodynamics of airframe/engine integration of high speed turbine powered aircraft. It lists 1535 unclassified documents published mainly in the period from 1955 to 1980. Primary emphasis was devoted to aerodynamic problems and interferences encountered in the integration process; however, extensive coverage also was given to the characteristics and problems of the isolated propulsion system elements. A detailed topic breakdown structure is used. The primary contents of the individual documents are indicated by the combination of the document's title and its location within the framework of the bibliography.

  8. In Search of the Physics: The Interplay of Experiment and Computation in Airframe Noise Research: Flap-Edge Noise

    NASA Technical Reports Server (NTRS)

    Streett, C. L.; Lockard, D. P.; Singer, B. A.; Khorrami, M. R.; Choudhari, M. M.

    2003-01-01

    The LaRC investigative process for airframe noise has proven to be a useful guide for elucidation of the physics of flow-induced noise generation over the last five years. This process, relying on a close interplay between experiment and computation, is described and demonstrated here on the archetypal problem of flap-edge noise. Some detailed results from both experiment and computation are shown to illustrate the process, and a description of the multi-source physics seen in this problem is conjectured.

  9. Integration of Propulsion-Airframe-Aeroacoustic Technologies and Design Concepts for a Quiet Blended-Wing-Body Transport

    NASA Technical Reports Server (NTRS)

    Hill, G. A.; Brown, S. A.; Geiselhart, K. A.

    2004-01-01

    This paper summarizes the results of studies undertaken to investigate revolutionary propulsion-airframe configurations that have the potential to achieve significant noise reductions over present-day commercial transport aircraft. Using a 300 passenger Blended-Wing-Body (BWB) as a baseline, several alternative low-noise propulsion-airframe-aeroacoustic (PAA) technologies and design concepts were investigated both for their potential to reduce the overall BWB noise levels, and for their impact on the weight, performance, and cost of the vehicle. Two evaluation frameworks were implemented for the assessments. The first was a Multi-Attribute Decision Making (MADM) process that used a Pugh Evaluation Matrix coupled with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). This process provided a qualitative evaluation of the PAA technologies and design concepts and ranked them based on how well they satisfied chosen design requirements. From the results of the evaluation, it was observed that almost all of the PAA concepts gave the BWB a noise benefit, but degraded its performance. The second evaluation framework involved both deterministic and probabilistic systems analyses that were performed on a down-selected number of BWB propulsion configurations incorporating the PAA technologies and design concepts. These configurations included embedded engines with Boundary Layer Ingesting Inlets, Distributed Exhaust Nozzles installed on podded engines, a High Aspect Ratio Rectangular Nozzle, Distributed Propulsion, and a fixed and retractable aft airframe extension. The systems analyses focused on the BWB performance impacts of each concept using the mission range as a measure of merit. Noise effects were also investigated when enough information was available for a tractable analysis. Some tentative conclusions were drawn from the results. One was that the Boundary Layer Ingesting Inlets provided improvements to the BWB's mission range, by

  10. An aeroacoustic study of micro-tab on airframe noise reduction

    NASA Astrophysics Data System (ADS)

    Kuo, Chiawei B.

    Aircraft high-lift devices such as leading-edge slats and trailing-edge flaps generate noise when extended, causing significant contributions to overall aircraft sound pressure levels, in particular in approach to land phase. It is shown by previous research efforts that noise generated by the high-lift devices increases with their deployment angles. Hence it is possible to mitigate such high-lift noise by using reduced settings without sacrificing the aerodynamic performance, particularly lift. In this dissertation research, micro-tab device attached at the pressure side of the flap surface near its trailing-edge is envisioned as the way to compensate the lift loss due to reduced high-lift device settings. Hybrid numerical method, which combines computational fluid dynamics and acoustics analogy, was adopted to predict the farfield noise spectrum. It is the goal of this research project to illustrate that noise level increase due to micro-tab deployment is smaller than that from the prescribed slat and flap setting increases, so that an overall airframe noise reduction can be achieved. Two-dimensional computational simulations and three-dimensional computational simulations were performed progressively. Results indicated that the proposed reduced high-lift settings with micro-tab application achieved noise reduction, particularly in the mid-frequency range where human hearing is most sensitive to. Parametric studies involving geometry and size effects of the micro-tab configurations were conducted using two-dimensional and three-dimensional models. Results showed that considerable noise reduction was obtained if slit micro-tab was used. An airworthiness study regarding applying micro-tab device onto existing commercial airliners as retrofit to lower noise emission in approach was also investigated and compliance strategy was provided. In the last part of this research, a different approach from aviation policy was taken as the airport noise compatibility planning

  11. Propulsion Airframe Aeroacoustics Technology Evaluation and Selection Using a Multi-Attribute Decision Making Process and Non-Deterministic Design

    NASA Technical Reports Server (NTRS)

    Burg, Cecile M.; Hill, Geoffrey A.; Brown, Sherilyn A.; Geiselhart, Karl A.

    2004-01-01

    The Systems Analysis Branch at NASA Langley Research Center has investigated revolutionary Propulsion Airframe Aeroacoustics (PAA) technologies and configurations for a Blended-Wing-Body (BWB) type aircraft as part of its research for NASA s Quiet Aircraft Technology (QAT) Project. Within the context of the long-term NASA goal of reducing the perceived aircraft noise level by a factor of 4 relative to 1997 state of the art, major configuration changes in the propulsion airframe integration system were explored with noise as a primary design consideration. An initial down-select and assessment of candidate PAA technologies for the BWB was performed using a Multi-Attribute Decision Making (MADM) process consisting of organized brainstorming and decision-making tools. The assessments focused on what effect the PAA technologies had on both the overall noise level of the BWB and what effect they had on other major design considerations such as weight, performance and cost. A probabilistic systems analysis of the PAA configurations that presented the best noise reductions with the least negative impact on the system was then performed. Detailed results from the MADM study and the probabilistic systems analysis will be published in the near future.

  12. Development of USES Specific Aptitude Test Battery S-111R84 for Airframe-and-Powerplant Mechanic (Aircraft-Aerospace Mfg.; Air Trans.) 621.281-014.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Human Resources, Salem.

    This report is designed to provide information required to evaluate the Specific Aptitude Test Battery (SATB) for Airframe-and-Powerplant Mechanic from three points of view: (1) technical adequacy of the research, (2) fairness to minorities, and (3) usefulness of the battery to Employment Service staff and employers in selecting individuals for…

  13. The NASA/industry design analysis methods for vibrations (DAMVIBS) program - Accomplishments and contributions

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    1991-01-01

    A NASA Langley-sponsored rotorcraft structural dynamics program, known as Design Analysis Methods for VIBrationS (DAMVIBS), has been under development since 1984. The objective of this program was to establish the technology base needed by the industry to develop an advanced finite-element-based dynamics design analysis capability for vibrations. Under the program, teams from the four major helicopter manufacturers have formed finite-element models, conducted ground vibration tests, made test/analysis comparisons of both metal and composite airframes, performed 'difficult components' studies on airframes to identify components which need more complete finite-element representation for improved correlation, and evaluated industry codes for computing coupled rotor-airframe vibrations. Studies aimed at establishing the role that structural optimization can play in airframe vibrations design work have also been initiated. Five government/industry meetings were held in connection with these activities during the course of the program. Because the DAMVIBS Program is coming to an end, the fifth meeting included a brief assessment of the program and its benefits to the industry.

  14. The NASA/industry design analysis methods for vibrations (DAMVIBS) program: Accomplishments and contributions

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    1991-01-01

    A NASA Langley-sponsored rotorcraft structural dynamics program, known as Design Analysis Methods for VIBrationS (DAMVIBS), has been under development since 1984. The objective of this program was to establish the technology base needed by the industry to develop an advanced finite-element-based dynamics design analysis capability for vibrations. Under the program, teams from the four major helicopter manufacturers have formed finite-element models, conducted ground vibration tests, made test/analysis comparisons of both metal and composite airframes, performed 'difficult components' studies on airframes to identify components which need more complete finite-element representation for improved correlation, and evaluated industry codes for computing coupled rotor-airframe vibrations. Studies aimed at establishing the role that structural optimization can play in airframe vibrations design work have also been initiated. Five government/industry meetings were held in connection with these activities during the course of the program. Because the DAMVIBS Program is coming to an end, the fifth meeting included a brief assessment of the program and its benefits to the industry.

  15. Results from an exploratory study of airframe noise on a small-scale model of a supersonic transport concept

    NASA Technical Reports Server (NTRS)

    Preisser, J. S.

    1977-01-01

    An exploratory study of airframe noise on a small-scale model of a supersonic transport concept was made. The model was a 0.015 scale version without landing gear of Langley's Advanced Supersonic Technology configuration concept, AST-110. Noise measurements were made at positions corresponding to directly beneath the model and at 30 deg - sideline, for both cruise and the approch flaps configurations, at velocities up to 34 m/s. In general, results showed the cruise noise to be about 3dB above the background flow noise and the approach noise to be about 11 dB above. Overall sound pressure levels and spectral shapes agreed with state of the art predictive techniques.

  16. FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

    NASA Technical Reports Server (NTRS)

    Harris, Charles E. (Editor)

    1994-01-01

    The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance.

  17. Summary of the Tandem Cylinder Solutions from the Benchmark Problems for Airframe Noise Computations-I Workshop

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2011-01-01

    Fifteen submissions in the tandem cylinders category of the First Workshop on Benchmark problems for Airframe Noise Computations are summarized. Although the geometry is relatively simple, the problem involves complex physics. Researchers employed various block-structured, overset, unstructured and embedded Cartesian grid techniques and considerable computational resources to simulate the flow. The solutions are compared against each other and experimental data from 2 facilities. Overall, the simulations captured the gross features of the flow, but resolving all the details which would be necessary to compute the noise remains challenging. In particular, how to best simulate the effects of the experimental transition strip, and the associated high Reynolds number effects, was unclear. Furthermore, capturing the spanwise variation proved difficult.

  18. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: McDonnell-Douglas Helicopter Company achievements

    NASA Technical Reports Server (NTRS)

    Toossi, Mostafa; Weisenburger, Richard; Hashemi-Kia, Mostafa

    1993-01-01

    This paper presents a summary of some of the work performed by McDonnell Douglas Helicopter Company under NASA Langley-sponsored rotorcraft structural dynamics program known as DAMVIBS (Design Analysis Methods for VIBrationS). A set of guidelines which is applicable to dynamic modeling, analysis, testing, and correlation of both helicopter airframes and a large variety of structural finite element models is presented. Utilization of these guidelines and the key features of their applications to vibration modeling of helicopter airframes are discussed. Correlation studies with the test data, together with the development and applications of a set of efficient finite element model checkout procedures, are demonstrated on a large helicopter airframe finite element model. Finally, the lessons learned and the benefits resulting from this program are summarized.

  19. Plan, execute, and discuss vibration measurements and correlations to evaluate a NASTRAN finite element model of the AH-64 helicopter airframe

    NASA Technical Reports Server (NTRS)

    Ferg, D.; Foote, L.; Korkosz, G.; Straub, F.; Toossi, M.; Weisenburger, R.

    1990-01-01

    A ground vibration test was performed on the AH-64 (Apache) helicopter to determine the frequency response of the airframe. The structure was excited at both the main and tail rotor hubs, separately, and response measurements were taken at 102 locations throughout the fuselage structure. Frequency responses were compared and correlated with results from a NASTRAN finite element model of AH-64. In addition, natural frequencies and mode shapes were estimated from the frequency response data and were correlated with analytical results.

  20. Development of Eddy Current Techniques for Detection of Deep Fatigue Cracks in Multi-Layer Airframe Components

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A.

    2008-01-01

    Thick, multi-layer aluminum structure has been widely used in aircraft design in critical wing splice areas. The multi-layer structure generally consists of three or four aluminum layers with different geometry and varying thickness, which are held together with fasteners. The detection of cracks under fasteners with ultrasonic techniques in subsurface layers away from the skin is impeded primarily by interlayer bonds and faying sealant condition. Further, assessment of such sealant condition is extremely challenging in terms of complexity of structure, limited access, and inspection cost. Although Eddy current techniques can be applied on in-service aircraft from the exterior of the skin without knowing sealant condition, the current eddy current techniques are not able to detect defects with wanted sensitivity. In this work a series of low frequency eddy current probes have been designed, fabricated and tested for this application. A probe design incorporating a shielded magnetic field sensor concentrically located in the interior of a drive coil has been employed to enable a localized deep diffusion of the electromagnetic field into the part under test. Due to the required low frequency inspections, probes have been testing using a variety of magnetic field sensors (pickup coil, giant magneto-resistive, anisotropic magneto-resistive, and spin-dependent tunneling). The probe designs as well as capabilities based upon a target inspection for sub-layer cracking in an airframe wing spar joint is presented.

  1. Technology transfer and other public policy implications of multi-national arrangements for the production of commercial airframes

    NASA Technical Reports Server (NTRS)

    Gellman, A. J.; Price, J. P.

    1978-01-01

    A study to examine the question of technology transfer through international arrangements for production of commercial transport aircraft is presented. The likelihood of such transfer under various representative conditions was determined and an understanding of the economic motivations for, effects of, joint venture arrangements was developed. Relevant public policy implications were also assessed. Multinational consortia with U.S. participation were focused upon because they generate the full range of pertinent public issues (including especially technology transfer), and also because of recognized trends toward such arrangements. An extensive search and analysis of existing literature to identify the key issues, and in-person interviews with executives of U.S. and European commercial airframe producers was reviewed. Distinctions were drawn among product-embodied, process, and management technologies in terms of their relative possibilities of transfer and the significance of such transfer. Also included are observations on related issues such as the implications of U.S. antitrust policy with respect to the formation of consortia and the competitive viability of the U.S. aircraft manufacturing industry.

  2. Thermal design and analysis of a hydrogen-burning wind tunnel model of an airframe-integrated scramjet

    NASA Technical Reports Server (NTRS)

    Guy, R. W.; Mueller, J. N.; Pinckney, S. Z.; Lee, L. P.

    1976-01-01

    An aerodynamic model of a hydrogen burning, airframe integrated scramjet engine has been designed, fabricated, and instrumented. This model is to be tested in an electric arc heated wind tunnel at an altitude of 35.39 km (116,094 ft.) but with an inlet Mach number of 6 simulating precompression on an aircraft undersurface. The scramjet model is constructed from oxygen free, high conductivity copper and is a heat sink design except for water cooling in some critical locations. The model is instrumented for pressure, surface temperature, heat transfer rate, and thrust measurements. Calculated flow properties, heat transfer rates, and surface temperature distributions along the various engine components are included for the conditions stated above. For some components, estimates of thermal strain are presented which indicate significant reductions in plastic strain by selective cooling of the model. These results show that the 100 thermal cycle life of the engine was met with minimum distortion while staying within the 2669 N (600 lbf) engine weight limitation and while cooling the engine only in critical locations.

  3. Design Processes and Criteria for the X-51A Flight Vehicle Airframe

    DTIC Science & Technology

    2007-11-01

    office [1]. The fundamental objective of the X-51A flight test program is to flight demonstrate the USAF Hypersonic Technology (HyTech) scramjet engine...external vehicle configuration utilizes a waverider-type aerodynamic mold line to maximize hypersonic lift to drag (L/D) ratios. The hypersonic cruise...capabilities in both 1) time critical, long range standoff response, 2) hypersonic reach/reconnaissance vehicles and 3) reusable on-demand access to

  4. Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

    2003-01-01

    A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

  5. Fatigue Damage Accumulation Under Quasi-Random Loading of Composite Airframe Elements

    NASA Astrophysics Data System (ADS)

    Strizhius, V.

    2016-09-01

    To perform engineering estimations of the fatigue life of quasi-randomly loaded layered composites, with geometric concentrators, representing the longitudinal elements of composite wing of a transport airplane, a special rule of fatigue damage accumulation is suggested. The main propositions of the method for calculating the fatigue life of these elements by using this rule are formulated. The examples of estimations presented show a good agreement between analytical results and experimental data. A number of important conclusions about the effect of different levels of cyclic loading and "GAG" cycles of different flight types of the quasi-random "TWIST" program on the total fatigue life are made.

  6. Development and Calibration of a Field-Deployable Microphone Phased Array for Propulsion and Airframe Noise Flyover Measurements

    NASA Technical Reports Server (NTRS)

    Humphreys, William M., Jr.; Lockard, David P.; Khorrami, Mehdi R.; Culliton, William G.; McSwain, Robert G.; Ravetta, Patricio A.; Johns, Zachary

    2016-01-01

    A new aeroacoustic measurement capability has been developed consisting of a large channelcount, field-deployable microphone phased array suitable for airframe noise flyover measurements for a range of aircraft types and scales. The array incorporates up to 185 hardened, weather-resistant sensors suitable for outdoor use. A custom 4-mA current loop receiver circuit with temperature compensation was developed to power the sensors over extended cable lengths with minimal degradation of the signal to noise ratio and frequency response. Extensive laboratory calibrations and environmental testing of the sensors were conducted to verify the design's performance specifications. A compact data system combining sensor power, signal conditioning, and digitization was assembled for use with the array. Complementing the data system is a robust analysis system capable of near real-time presentation of beamformed and deconvolved contour plots and integrated spectra obtained from array data acquired during flyover passes. Additional instrumentation systems needed to process the array data were also assembled. These include a commercial weather station and a video monitoring / recording system. A detailed mock-up of the instrumentation suite (phased array, weather station, and data processor) was performed in the NASA Langley Acoustic Development Laboratory to vet the system performance. The first deployment of the system occurred at Finnegan Airfield at Fort A.P. Hill where the array was utilized to measure the vehicle noise from a number of sUAS (small Unmanned Aerial System) aircraft. A unique in-situ calibration method for the array microphones using a hovering aerial sound source was attempted for the first time during the deployment.

  7. Hyper-X Wind Tunnel Program

    NASA Technical Reports Server (NTRS)

    McClinton, C. R.; Holland, S. D.; Rock, K. E.; Engelund, W. C.; Voland, R. T.; Huebner, L. D.; Roger, R. C.

    1998-01-01

    This paper provides an overview of NASA's focused hypersonic technology program, called the Hyper-X Program. The Hyper-X Program, a joint NASA Langley and Dryden program, is designed to move hypersonic, air breathing vehicle technology from the laboratory environment to the flight environment, the last stage preceding prototype development. The Hyper-X research vehicle will provide the first ever opportunity to obtain data on an airframe integrated scramjet (supersonic combustion ramjet) propulsion system at true flight conditions and the first opportunity for flight validation of experimental wind tunnel, numerical and analytical methods used for design of these vehicles. A substantial portion of the program is experimentally based, both for database development and performance validation. The program is now concentrating on Mach 7 vehicle development, verification and validation and flight test risk reduction. This paper concentrates on the aerodynamic and propulsion experimental programs. Wind tunnel testing of the flight engine and complete airframe integrated scramjet configuration flow-path is expected in 1998 and 1999, respectively, and flight test is planned for 2000.

  8. Nozzle performance calibration and turbomachinery operational analysis of Turbo-Powered Simulators (TPS) for the NASA-Langley EET propulsion airframe integration investigation

    NASA Technical Reports Server (NTRS)

    Rowe, R. K.

    1982-01-01

    The Boeing flight simulator chamber facility energy efficient transport (EET) propulsion/airframe integration investigation was tested. Two turbopowered simulators (TPS) were calibrated with four different nacelle configurations. Two nacelle configurations were calibrated on each TPS, each calibration simulating the full nozzle pressure ratio range encountered in a one atmosphere total pressure wind tunnel operating over a Mach number range from 0.70 to 0.90 Mach. The results of the calibration test are in the form of velocity and discharge coefficient which is used in determining the simulator thrust while the TPS is operating in the wind tunnel.

  9. Status of the NASA YF-12 Propulsion Research Program

    NASA Technical Reports Server (NTRS)

    Albers, J. A.

    1976-01-01

    The YF-12 research program was initiated to establish a technology base for the design of an efficient propulsion system for supersonic cruise aircraft. The major technology areas under investigation in this program are inlet design analysis, propulsion system steady-state performance, propulsion system dynamic performance, inlet and engine control systems, and airframe/propulsion system interactions. The objectives, technical approach, and status of the YF-12 propulsion program are discussed. Also discussed are the results obtained to date by the NASA Ames, Lewis, and Dryden research centers. The expected technical results and proposed future programs are also given. Propulsion system configurations are shown.

  10. User's manual for the coupled mode version of the normal modes rotor aeroelastic analysis computer program

    NASA Technical Reports Server (NTRS)

    Bergquist, R. R.; Carlson, R. G.; Landgrebe, A. J.; Egolf, T. A.

    1974-01-01

    This User's Manual was prepared to provide the engineer with the information required to run the coupled mode version of the Normal Modes Rotor Aeroelastic Analysis Computer Program. The manual provides a full set of instructions for running the program, including calculation of blade modes, calculations of variable induced velocity distribution and the calculation of the time history of the response for either a single blade or a complete rotor with an airframe (the latter with constant inflow).

  11. Airframe/Propulsion Interference

    DTIC Science & Technology

    1975-03-01

    described in reference 6. Figure 4 shows the model in schematic form. ENGINE FACE VENTURI EXIT STATICS . PRESSURE RATTED BASE EARTHED STING... EARTHED CONICAL THROTTLE < FIG. L. MODEL INSTRUMENTATION 3-4 Twin side intakes and internal ducts are representative to the engine face. Aft of the...exit momentum are downstream of the Venturis in a constant diameter exit tube. Mass flow is controlled by an earthed , 60 conical plug throttle with

  12. Crashworthiness of Airframes.

    DTIC Science & Technology

    1986-04-01

    INTRODUCTION During the 1970s, the application of computer technology to analyze large nonlinear behavior of rotary and fixed-wing aircraft structure improved...is to bring together the leading personalities of the NATO nations in the fields of science and technology relating to aerospace for the following...Imperial College of Science and Technology , London, U.K. (Originally presented at the 61st Meeting of the Structures and Materials Panel, September

  13. Ramjets: Airframe Integration

    DTIC Science & Technology

    2010-09-01

    Thermal Management (Propulsion a vitesse elevee : Conception du moteur - integration et gestion thermique) 14. ABSTRACT These notes deal with the...to those of the ambient air (γ=1.4) • No effects of fuel mass addition (mf << ma) • Complete combustion of the fuel yielding CO2 and H2O as reaction...which leads to a nozzle exit plane static pressure pe that is not necessarily equal to the ambient pressure p0. At zero angle-of-attack the inlet

  14. Academic Airframe Icing Perspective

    NASA Technical Reports Server (NTRS)

    Bragg, Mike; Rothmayer, Alric; Thompson, David

    2009-01-01

    2-D ice accretion and aerodynamics reasonably well understood for engineering applications To significantly improve our current capabilities we need to understand 3-D: a) Important ice accretion physics and modeling not well understood in 3-D; and b) Aerodynamics unsteady and 3-D especially near stall. Larger systems issues important and require multidisciplinary team approach

  15. NASA's Advanced Space Transportation Hypersonic Program

    NASA Technical Reports Server (NTRS)

    Hueter, Uwe; McClinton, Charles; Cook, Stephen (Technical Monitor)

    2002-01-01

    NASA's has established long term goals for access-to-space. NASA's third generation launch systems are to be fully reusable and operational in approximately 25 years. The goals for third generation launch systems are to reduce cost by a factor of 100 and improve safety by a factor of 10,000 over current conditions. The Advanced Space Transportation Program Office (ASTP) at NASA's Marshall Space Flight Center in Huntsville, AL has the agency lead to develop third generation space transportation technologies. The Hypersonics Investment Area, part of ASTP, is developing the third generation launch vehicle technologies in two main areas, propulsion and airframes. The program's major investment is in hypersonic airbreathing propulsion since it offers the greatest potential for meeting the third generation launch vehicles. The program will mature the technologies in three key propulsion areas, scramjets, rocket-based combined cycle and turbine-based combination cycle. Ground and flight propulsion tests are being planned for the propulsion technologies. Airframe technologies will be matured primarily through ground testing. This paper describes NASA's activities in hypersonics. Current programs, accomplishments, future plans and technologies that are being pursued by the Hypersonics Investment Area under the Advanced Space Transportation Program Office will be discussed.

  16. Seamless Military/Civilian Transition: Holding the Operational Force Together

    DTIC Science & Technology

    2010-12-14

    themselves as the member of a team. The single document that encompasses this passion is the resume. The Army Career and Alumni Program ( ACAP ...retrieve data. The ACAP of today is a robust program requiring at least 40 hours, providing classes, workshops, and one-on-one counseling on topics...is the web-based search services. The ACAP program is one tool that no doubt assists the Soldier along the continuum of service; however, not all

  17. Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe

    NASA Technical Reports Server (NTRS)

    Mayo, Wilbur L

    1952-01-01

    Solutions of impact of a rigid prismatic float connected by a massless spring to a rigid upper mass are presented. The solutions are based on hydrodynamic theory which has been experimentally confirmed for a rigid structure. Equations are given for defining the spring constant and the ratio of the sprung mass to the lower mass so that the two-mass system provides representation of the fundamental mode of an airplane wing. The forces calculated are more accurate than the forces which would be predicted for a rigid airframe since the effect of the fundamental mode on the hydrodynamic force is taken into account. In a comparison of the theoretical data with data for a severe flight-test landing impact, the effect of the fundamental mode on the hydrodynamic force is considered and response data are compared with experimental data.

  18. Hyper-X Program Status

    NASA Technical Reports Server (NTRS)

    McClinton, Charles R.; Reubush, David E.; Sitz, Joel; Reukauf, Paul

    2001-01-01

    This paper provides an overview of the objectives and status of the Hyper-X program, which is tailored to move hypersonic, airbreathing vehicle technology from the laboratory environment to the flight environment. The first Hyper-X research vehicle (HXRV), designated X-43, is being prepared at the Dryden Flight Research Center for flight at Mach 7. Extensive risk reduction activities for the first flight are completed, and non-recurring design activities for the Mach 10 X-43 (third flight) are nearing completion. The Mach 7 flight of the X-43, in the spring of 2001, will be the first flight of an airframe-integrated scramjet-powered vehicle. The Hyper-X program is continuing to plan follow-on activities to focus an orderly continuation of hypersonic technology development through flight research.

  19. Hyper-X Program Status

    NASA Technical Reports Server (NTRS)

    McClinton, Charles R.; Rausch, Vincent L.; Sitz, Joel; Reukauf, Paul

    2001-01-01

    This paper provides an overview of the objectives and status of the Hyper-X program, which is tailored to move hypersonic, airbreathing vehicle technology from the laboratory environment to the flight environment. The first Hyper-X research vehicle (HXRV), designated X-43, is being prepared at the Dryden Flight Research Center for flight at Mach 7. Extensive risk reduction activities for the first flight are completed, and non-recurring design activities for the Mach 10 X-43 (3rd flight) are nearing completion. The Mach 7 flight of the X-43, in the spring of 2001, will be the first flight of an airframe-integrated scramjet-powered vehicle. The Hyper-X program is continuing to plan follow-on activities to focus an orderly continuation of hypersonic technology development through flight research.

  20. Summary highlights of the Advanced Rotorcraft Transmission (ART) program

    NASA Technical Reports Server (NTRS)

    Bill, Robert C.

    1992-01-01

    The NASA/U.S. Army Advanced Rotorcraft Transmission (ART) program is charged with the development and demonstration of lightweight, durable drivetrains for next-generation rotorcraft: (1) a Future Air Attack Vehicle for tactical ground-support and air-to-air missions, and (2) an Advanced Cargo Aircraft for heavy-lift field-support operations. Both tilt-rotor and more conventional helicopter configurations have been studied by the ART program. ART performance goals are sought through the use of advanced component materials and lubrication systems, transmission and geartrain configurations, and airframe/drivetrain integrations.

  1. The aircraft energy efficiency active controls technology program

    NASA Technical Reports Server (NTRS)

    Hood, R. V., Jr.

    1977-01-01

    Broad outlines of the NASA Aircraft Energy Efficiency Program for expediting the application of active controls technology to civil transport aircraft are presented. Advances in propulsion and airframe technology to cut down on fuel consumption and fuel costs, a program for an energy-efficient transport, and integrated analysis and design technology in aerodynamics, structures, and active controls are envisaged. Fault-tolerant computer systems and fault-tolerant flight control system architectures are under study. Contracts with leading manufacturers for research and development work on wing-tip extensions and winglets for the B-747, a wing load alleviation system, elastic mode suppression, maneuver-load control, and gust alleviation are mentioned.

  2. Federal Aviation Administration aircraft inspection research and develoment programs

    NASA Astrophysics Data System (ADS)

    Smith, Christopher D.

    1996-11-01

    A substantial and coordinated program in inspection system research was initiated at the FAA Technical Center in 1990 as part of the National Aging Aircraft Research Program. the primary objectives of the inspection systems initiative are to develop improved inspection techniques to address specific aging airframe and engine inspection problems and to evaluate and validate existing and emerging inspection systems. Advanced conventional technologies, emerging technologies, or combinations of technologies are investigated for their ability to accurately and reliably detect cracks, disbonds, corrosion, and other damage. This paper will present an overview of FAA inspection system research initiatives, but will focus primarily on the technical issues which have defined and prioritized those initiatives.

  3. High Speed Research Program Sonic Fatigue

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A. (Technical Monitor); Beier, Theodor H.; Heaton, Paul

    2005-01-01

    The objective of this sonic fatigue summary is to provide major findings and technical results of studies, initiated in 1994, to assess sonic fatigue behavior of structure that is being considered for the High Speed Civil Transport (HSCT). High Speed Research (HSR) program objectives in the area of sonic fatigue were to predict inlet, exhaust and boundary layer acoustic loads; measure high cycle fatigue data for materials developed during the HSR program; develop advanced sonic fatigue calculation methods to reduce required conservatism in airframe designs; develop damping techniques for sonic fatigue reduction where weight effective; develop wing and fuselage sonic fatigue design requirements; and perform sonic fatigue analyses on HSCT structural concepts to provide guidance to design teams. All goals were partially achieved, but none were completed due to the premature conclusion of the HSR program. A summary of major program findings and recommendations for continued effort are included in the report.

  4. NASA's Hyper-X Program

    NASA Technical Reports Server (NTRS)

    Rausch, Vincent L.; McClinton, Charles R.; Sitz, Joel; Reukauf, Paul

    2000-01-01

    This paper provides an overview of the objectives and status of the Hyper-X program which is tailored to move hypersonic, airbreathing vehicle technology from the laboratory environment to the flight environment, the last stage preceding prototype development. The first Hyper-X research vehicle (HXRV), designated X-43, is being prepared at the Dryden Flight Research Center for flight at Mach 7 in the near future. In addition, the associated booster and vehicle-to-booster adapter are being prepared for flight and flight test preparations are well underway. Extensive risk reduction activities for the first flight and non-recurring design for the Mach 10 X-43 (3rd flight) are nearing completion. The Mach 7 flight of the X-43 will be the first flight of an airframe-integrated scramjet-powered vehicle.

  5. Propulsion Induced Effects (PIE) Test Program

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina; Won, Mark J.

    1999-01-01

    The Propulsion Induced Effects (PIE) test program is being lead by NASA Ames for Configuration Aerodynamics (CA). Representatives from CA, Technology Integration (TI), Inlet, and the Nozzle ITD's are working with Ames in defining and executing this test program. The objective of the CA 4-14 milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane (TCA) and design variations using computational and experimental methods. The experimental aspect includes static calibrations, transonic and supersonic wind tunnel testing. The test program will generate a comprehensive database that will include all appropriate wind tunnel corrections, with emphasis placed on establishing the propulsion induced effects on the flight performance of the TCA.

  6. Technology Innovations from NASA's Next Generation Launch Technology Program

    NASA Technical Reports Server (NTRS)

    Cook, Stephen A.; Morris, Charles E. K., Jr.; Tyson, Richard W.

    2004-01-01

    NASA's Next Generation Launch Technology Program has been on the cutting edge of technology, improving the safety, affordability, and reliability of future space-launch-transportation systems. The array of projects focused on propulsion, airframe, and other vehicle systems. Achievements range from building miniature fuel/oxygen sensors to hot-firings of major rocket-engine systems as well as extreme thermo-mechanical testing of large-scale structures. Results to date have significantly advanced technology readiness for future space-launch systems using either airbreathing or rocket propulsion.

  7. Application of Linear Array Imaging Techniques to the Real-Time Inspection of Airframe Structures and Substructures

    NASA Technical Reports Server (NTRS)

    Miller, James G. (Principal Investigator)

    1996-01-01

    Current concern for ensuring, the air-worthiness of the aging commercial air fleet has prompted the establishment of broad-agency programs to develop NDT technologies that address specific aging-aircraft issues. One of the crucial technological needs that has been identified is the development of rapid, quantitative systems for depot-level inspection of bonded aluminum lap joints on aircraft. Research results for characterization of disbond and corrosion based on normal-incidence pulse-echo measurement geometries are showing promise, but are limited by the single-site nature of the measurement which requires manual or mechanical scanning to inspect an area. One approach to developing efficient systems may be to transfer specific aspects of current medical imaging technology to the NDT arena. Ultrasonic medical imaging, systems offer many desirable attributes for large scale inspection. They are portable, provide real-time imaging, and have integrated video tape recorder and printer capabilities available for documentation and post-inspection review. Furthermore, these systems are available at a relatively low cost (approximately $50,000 to $200,000) and can be optimized for use with metals with straight-forward modifications.

  8. Selected topics from the structural acoustics program for the B-1 aircraft

    NASA Technical Reports Server (NTRS)

    Belcher, P. M.

    1979-01-01

    The major elements of the structural acoustics program for the B-1 aircraft are considered. Acoustic pressures measured at 280 sites on the surface of the vehicle were used to develop pressure models for a resizing of airframe components for aircraft No. 4 (A/C4). Acoustical fatigue design data for two dynamically complex structural configurations were acquired in laboratory programs, the conceptions for and executions of which detailed significant departures from the conventional. Design requirements for mechanical fasteners for configurations other than these two made use of analytical extensions of regrettably limited available information.

  9. Overview of the ACT program

    NASA Technical Reports Server (NTRS)

    Davis, John G., Jr.

    1992-01-01

    NASA's Advanced Composites Program (ACT) was initiated in 1988. A National Research Announcement was issued to solicit innovative ideas that could significantly contribute to development and demonstration of an integrated technology data base and confidence level that permits cost-effective use of composite primary structures in transport aircraft. Fifteen contracts were awarded by the Spring of 1989 and the participants include commercial and military airframe manufacturers, materials developers and suppliers, universities, and government laboratories. The program approach is to develop materials, structural mechanics methodology, design concepts, and fabrication procedures that offer the potential to make composite structures cost-effective compared to aluminum structure. Goals for the ACT program included 30-50 percent weight reduction, 20-25 percent acquisition cost reduction, and provided the scientific basis for predicting materials and structures performance. This paper provides an overview of the ACT program status, plans, and selected technical accomplishments. Sixteen additional papers, which provide more detailed information on the research and development accomplishments, are contained in this publication.

  10. Computer program to predict aircraft noise levels

    NASA Technical Reports Server (NTRS)

    Clark, B. J.

    1981-01-01

    Methods developed at the NASA Lewis Research Center for predicting the noise contributions from various aircraft noise sources were programmed to predict aircraft noise levels either in flight or in ground tests. The noise sources include fan inlet and exhaust, jet, flap (for powered lift), core (combustor), turbine, and airframe. Noise propagation corrections are available for atmospheric attenuation, ground reflections, extra ground attenuation, and shielding. Outputs can include spectra, overall sound pressure level, perceived noise level, tone-weighted perceived noise level, and effective perceived noise level at locations specified by the user. Footprint contour coordinates and approximate footprint areas can also be calculated. Inputs and outputs can be in either System International or U.S. customary units. The subroutines for each noise source and propagation correction are described. A complete listing is given.

  11. Advanced rotorcraft transmission program

    NASA Technical Reports Server (NTRS)

    Bill, Robert C.

    1990-01-01

    The Advanced Rotorcraft Transmission (ART) program is an Army-funded, joint Army/NASA program to develop and demonstrate lightweight, quiet, durable drivetrain systems for next generation rotorcraft. ART addresses the drivetrain requirements of two distinct next generation aircraft classes: Future Air Attack Vehicle, a 10,000 to 20,000 lb. aircraft capable of undertaking tactical support and air-to-air missions; and Advanced Cargo Aircraft, a 60,000 to 80,000 lb. aircraft capable of heavy life field support operations. Both tiltrotor and more conventional helicopter configurations are included in the ART program. Specific objectives of ART include reduction of drivetrain weight by 25 percent compared to baseline state-of-the-art drive systems configured and sized for the next generation aircraft, reduction of noise level at the transmission source by 10 dB relative to a suitably sized and configured baseline, and attainment of at least a 5000 hr mean-time-between-removal. The technical approach for achieving the ART goals includes application of the latest available component, material, and lubrication technology to advanced concept drivetrains that utilize new ideas in gear configuration, transmission layout, and airframe/drivetrain integration. To date, candidate drivetrain systems were carried to a conceptual design stage, and tradeoff studies were conducted resulting in selection of an ART transmission configuration for each of the four contractors. The final selection was based on comparative weight, noise, and reliability studies. A description of each of the selected ART designs is included. Preliminary design of each of the four selected ART transmission was completed, as have mission impact studies wherein comparisons of aircraft mission performance and life cycle costs are undertaken for the next generation aircraft with ART and with the baseline transmission.

  12. General aviation crash safety program at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.

    1976-01-01

    The purpose of the crash safety program is to support development of the technology to define and demonstrate new structural concepts for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: full-scale crash simulation testing, nonlinear structural analyses necessary to predict failure modes and collapse mechanisms of the vehicle, and evaluation of energy absorption concepts for specific component design. Both analytical and experimental methods are being used to develop expertise in these areas. Analyses include both simplified procedures for estimating energy absorption capabilities and more complex computer programs for analysis of general airframe response. Full-scale tests of typical structures as well as tests on structural components are being used to verify the analyses and to demonstrate improved design concepts.

  13. HSCT Propulsion Airframe Integration Studies

    NASA Technical Reports Server (NTRS)

    Chaney, Steve

    1999-01-01

    The Lockheed Martin spillage study was a substantial effort and is worthy of a separate paper. However, since a paper was not submitted a few of the most pertinent results have been pulled out and included in this paper. The reader is urged to obtain a copy of the complete Boeing Configuration Aerodynamics final 1995 contract report for the complete Lockheed documentation of the spillage work. The supersonic cruise studies presented here focus on the bifurcated - axisymmetric inlet drag delta. In the process of analyzing this delta several test/CFD data correlation problems arose that lead to a correction of the measured drag delta from 4.6 counts to 3.1 counts. This study also lead to much better understanding of the OVERFLOW gridding and solution process, and to increased accuracy of the force and moment data. Detailed observations of the CFD results lead to the conclusion that the 3.1 count difference between the two inlet types could be reduced to approximately 2 counts, with an absolute lower bound of 1.2 counts due to friction drag and the bifurcated lip bevel.

  14. Control of Spinning Symmetric Airframes

    DTIC Science & Technology

    2006-11-14

    IdH dt UNCLASSIFIED UNCLASSIFIED again using the transport theorem IdH dt = BdH dt + ωB/I ×H V. Body Axis System Equations of Motion The equations... IdH dt X MExt = IdH dt = ³ IxxṖ + IQR− IQR ´ ı̂B + ³ IQ̇+ IxxPR− IPR ´ ĵB + ³ IṘ+ IPQ− IxxPQ ´ k̂B or in component form IxxṖ =Mx IQ̇+ IxxPR− IPR...moment equations are X MExt = IdH dt = φdH dt + ωφ/I ×H = φdĪC · ωB/I dt + ωφ/I × ³ ĪC · ωB/I ´ we must now pause and look at the time rate

  15. Small Airframe Manufacturer's Icing Perspective

    NASA Technical Reports Server (NTRS)

    Hoppins, Jim

    2009-01-01

    This viewgraph presentation describes the icing effects, risk mitigation practices, and icing certifications for various Cessna small aircraft models. NASA's role in the development of simulation tools for icing certifications is also discussed.

  16. National Cycle Program (NCP) Common Analysis Tool for Aeropropulsion

    NASA Technical Reports Server (NTRS)

    Follen, G.; Naiman, C.; Evans, A.

    1999-01-01

    Through the NASA/Industry Cooperative Effort (NICE) agreement, NASA Lewis and industry partners are developing a new engine simulation, called the National Cycle Program (NCP), which is the initial framework of NPSS. NCP is the first phase toward achieving the goal of NPSS. This new software supports the aerothermodynamic system simulation process for the full life cycle of an engine. The National Cycle Program (NCP) was written following the Object Oriented Paradigm (C++, CORBA). The software development process used was also based on the Object Oriented paradigm. Software reviews, configuration management, test plans, requirements, design were all apart of the process used in developing NCP. Due to the many contributors to NCP, the stated software process was mandatory for building a common tool intended for use by so many organizations. The U.S. aircraft and airframe companies recognize NCP as the future industry standard for propulsion system modeling.

  17. Fiber Optic Repair and Maintainability (FORM) Program Progresses

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Advanced aircraft will employ fiber-optic interconnection components to transmit information from airframe and propulsion sensors to the flight control computers. Although these optical interconnects have been rigorously tested under laboratory conditions to determine their operating and environmental limits, there is concern as to their repairability and maintainability when placed in actual service. The Fiber Optic Repair and Maintainability (FORM) flight test program will provide data to enable designers to improve these fiber-optic interconnection systems for the next generation of aircraft. FORM is identifying critical problems in installing, maintaining, testing, and repairing fiber-optic interconnection systems in an operational avionics environment. This program is a cooperative Government/industry effort to evaluate optical component acceptability and installation techniques for aircraft.

  18. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    The High-Speed Research Program sponsored the NASA High-Speed Research Program Aerodynamic Performance Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of: Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization) and High-Lift. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. The HSR AP Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas within the airframe element of the HSR Program. This Volume 2/Part 1 publication presents the High-Lift Configuration Development session.

  19. Role of Mechanics of Textile Preform Composites in the NASA Advanced Composites Technology Program

    SciTech Connect

    Harris, C.E.; Poe, C.C. Jr.

    1995-10-01

    The Advanced Composites Technology Program was initiated by NASA as a partnership with the United States aeronautical industry in fiscal year 1989. The broad objective of the Program was to develop the technology to design and manufacture cost-effective and structurally optimized light-weight composite airframe primary structure. Phase A of the Program, 1989-1991, focused on the identification and evaluation of innovative manufacturing technologies and structural concepts. At the end of Phase A, the leading wing and fuselage design concepts were down-selected for further development in Phase B of the Program, 1992-1995. Three major fabrication technologies emerged from Phase A. These three approaches were the stitched dry preform, textile preform, and automated tow placement manufacturing methods. Each method emphasized rapid fiber placement, near net-shape preform fabrication, part count minimization, and matching the technologies to the specific structural configurations and requirements. The objective of Phase B was to continue the evolution of design concepts using the concurrent engineering process, down-select to the leading structural concept, and design, build, and test subscale components. Phase C of the ACT Program, 1995-2002, is a critical element of the NASA Advanced Subsonic Technology Program and has been approved for implementation beginning in 1995. The objective of Phase C is to design, build, and test major components of the airframe to demonstrate the technology readiness for applications in the next generation subsonic commercial transport aircraft. Part of the technology readiness demonstration will include a realistic comparison of manufacturing costs and an increased confidence in the ability to accurately estimate the costs of composite structure. The Program Plan calls for the structural components to be a complete fuselage barrel with a window-belt and a wing box at the wing/fuselage intersection.

  20. NASA/FAA general aviation crash dynamics program

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Hayduk, R. J.; Carden, H. D.

    1981-01-01

    The program involves controlled full scale crash testing, nonlinear structural analyses to predict large deflection elastoplastic response, and load attenuating concepts for use in improved seat and subfloor structure. Both analytical and experimental methods are used to develop expertise in these areas. Analyses include simplified procedures for estimating energy dissipating capabilities and comprehensive computerized procedures for predicting airframe response. These analyses are developed to provide designers with methods for predicting accelerations, loads, and displacements on collapsing structure. Tests on typical full scale aircraft and on full and subscale structural components are performed to verify the analyses and to demonstrate load attenuating concepts. A special apparatus was built to test emergency locator transmitters when attached to representative aircraft structure. The apparatus is shown to provide a good simulation of the longitudinal crash pulse observed in full scale aircraft crash tests.

  1. Computer program to assess impact of fatigue and fracture criteria on weight and cost of transport aircraft

    NASA Technical Reports Server (NTRS)

    Tanner, C. J.; Kruse, G. S.; Oman, B. H.

    1975-01-01

    A preliminary design analysis tool for rapidly performing trade-off studies involving fatigue, fracture, static strength, weight, and cost is presented. Analysis subprograms were developed for fatigue life, crack growth life, and residual strength; and linked to a structural synthesis module which in turn was integrated into a computer program. The part definition module of a cost and weight analysis program was expanded to be compatible with the upgraded structural synthesis capability. The resultant vehicle design and evaluation program is named VDEP-2. It is an accurate and useful tool for estimating purposes at the preliminary design stage of airframe development. A sample case along with an explanation of program applications and input preparation is presented.

  2. A computer program for the prediction of near field noise of aircraft in cruising flight: User's guide

    NASA Technical Reports Server (NTRS)

    Tibbetts, J. G.

    1980-01-01

    Detailed instructions for using the near field cruise noise prediction program, a program listing, and a sample case with output are presented. The total noise for free field lossless conditions at selected observer locations is obtained by summing the contributions from up to nine acoustic sources. These noise sources, selected at the user's option, include the fan/compressor, turbine, core (combustion), jet, shock, and airframe (trailing edge and turbulent boundary layers). The effects of acoustic suppression materials such as engine inlet treatment may also be included in the noise prediction. The program is available for use on the NASA/Langley Research Center CDC computer. Comparisons of the program predictions with measured data are also given, and some possible reasons for their lack of agreement presented.

  3. Refan program. Phase 1: Summary report

    NASA Technical Reports Server (NTRS)

    Sams, E. W.; Bresnahan, D. L.

    1973-01-01

    The Refan Program is aimed at a large reduction in aircraft approach and takeoff noise in the vicinity of airports caused by the JT3D-powered 707's and DC-8's and the JT8D-powered 727's, 737's and DC-9's. These aircraft represent a major part of the existing commercial fleet. The noise reductions can be achieved by engine and nacelle modifications in the form of aircraft retrofit kits. Engine turbomachinery noise is reduced by replacing the current two-stage fan with a larger single-stage fan and by nacelle acoustic treatment. Jet noise is reduced by the reduction on jet velocity caused by additional turbine work extraction to drive the larger bypass fan. The predicted net effect of these modifications on installed performance is large noise reductions on both approach and takeoff, increased takeoff thrust, decreased takeoff field length, and maintained or improved aircraft range depending on the amount of acoustic treatment included. The Refan Program is being conducted in two phases under contracts with one engine and two airframe companies. Results of the Phase I work are summarized in this report which describes the refan nacelle configurations studied, the airplane modifications required to install the nacelles, and the resulting airplane performance and noise reductions predicted for all five aircraft.

  4. MIZEX, A Program for Mesoscale Air-Ice-Ocean Interaction Experiments in Arctic Marginal Ice Zones. VI. MIZEX-WEST,

    DTIC Science & Technology

    1985-05-01

    tamed. SUMMARY The winter 1983 temperature and salinity data S % gmO -t 25 .... 26 from the Bering Sea MIZ provided the most de- Toc -2 .. tailed...are defined as fol- lows: our data: o. Okubo’s data: *-North Sea; A-Cape Kennedy; + - Banana River; x -Manokin River; *-New York Bight; [-South- ern

  5. Analytical developments in support of the NASA aging aircraft program with an application to crack growth from rivets

    NASA Astrophysics Data System (ADS)

    Swenson, Daniel; Gondhalekar, Sudhir; Dawicke, Dave

    The NASA Airframe Structural Integrity Program is a multi-disciplinary program to develop analysis methodology, a fracture data base, and improved methods of nondestructive evaluation (NDE) detection of disbonds and cracks. As part of this program, analysis tools to predict crack growth rates and fracture propagation in shell structures are being developed. This paper describes a finite element model of crack growth in layered structures, such as lap splice joints. The model is developed using separate two-dimensional meshes of individual layers which can overlap in space. These layers can be connected with either rivit elements or by adhesive elements. Cracks can be modeled in any layer, with automatic remeshing during crack growth. Using the model, an investigation was made of the effect of rivet interference on fatigue crack growth from a loaded rivit hole. It was found that the interference reduced the stress intensity factor range significantly, resulting in slower crack growth.

  6. Experimental evaluation of nacelle-airframe interference forces and pressures at Mach numbers of 0.9 to 1.4

    NASA Technical Reports Server (NTRS)

    Bencze, D. P.

    1977-01-01

    Detailed interference force-and-pressure data were obtained on a representative supersonic transport wing-body-nacelle combination at Mach numbers of 0.9 to 1.4. The basic model consisted of a delta wing-body aerodynamic model with a length of 158.0 cm (62.2 in.) and a wingspan of 103.6 cm (40.8 in.) and four independently supported nacelles positioned beneath the model. The experimental program was conducted in the Ames 11- by 11-Foot Wind Tunnel at a constant unit Reynolds number. The primary variables examined included Mach number, angle of attack, nacelle position, and nacelle mass-flow ratio. Under the most favorable conditions, the net interference drag was equal to 50 percent the drag of four isolated nacelles at M = 1.4, 75 percent at M = 1.15, and 144 percent at M = 0.90. The overall interference effects were found to be rather constant over the operating angle-of-attack range of the configuration. The effects of mass-flow ratio on the interference pressure distributions were limited to the lip region of the nacelle and the local wing surface in the immediate vicinity of the nacelle lip. The net change in the measured interference forces resulting from variations in the nacelle mass-flow ratio were found to be quite small.

  7. Results of a wind tunnel/flight test program to compare afterbody/nozzle pressures on a 1/12 scale model and an F-15 aircraft

    NASA Technical Reports Server (NTRS)

    Pendergraft, O. C., Jr.; Nugent, J.

    1984-01-01

    In 1975 NASA Dryden Flight Research Facility received the No. 2 prototype F-15 aircraft from the USAF to conduct the F-15 Propulsion/Airframe Interactions Program. About the same time, NASA Langley Research Center acquired a 1/12 scale F-15 propulsion model, whose size made it suitable for detailed afterbody/nozzle static pressure distribution studies. Close coordination between Langley and Dryden assured identical orifice locations and nozzle geometries on the model and aircraft. This paper discusses the sequence of the test programs and how retesting the model after completion of the flight tests greatly increased the ability to match hardware and test conditions. The experience gained over the past decade from involvement in the program should prove valuable to any future programs attempting to match wind tunnel and flight test conditions and hardware.

  8. NASA-UVa light aerospace alloy and structures technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr. (Editor)

    1995-01-01

    This report on the NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from July 1, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) Ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) Powder metallurgy 2XXX alloys, (3) Rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) Discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  9. Validation of a Flexible Aircraft TakeOff and Landing Analysis /FATOLA/ computer program using flight landing data

    NASA Technical Reports Server (NTRS)

    Carden, H. D.; Mcgehee, J. R.

    1977-01-01

    A multiple-degree-of-freedom takeoff and landing analysis, Flexible Aircraft TakeOff and Landing Analysis computer program (FATOLA), was used to predict the landing behavior of a rigid-body X-24B reentry research vehicle and of a flexible-body modified-delta-wing supersonic YF-12 research aircraft. The analytical predictions were compared with flight test data for both research vehicles. Predicted time histories of vehicle motion and attitude, landing-gear strut stroke, and axial force transmitted from the landing gear to the airframe during the landing impact and rollout compared well with the actual time histories. Based on the comparisons presented, the versatility and validity of the FATOLA program for predicting landing dynamics of aircraft has been demonstrated.

  10. A History of Full-Scale Aircraft and Rotorcraft Crash Testing and Simulation at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.; Lyle, Karen H.

    2004-01-01

    This paper summarizes 2-1/2 decades of full-scale aircraft and rotorcraft crash testing performed at the Impact Dynamics Research Facility (IDRF) located at NASA Langley Research Center in Hampton, Virginia. The IDRF is a 240-ft.-high steel gantry that was built originally as a lunar landing simulator facility in the early 1960's. It was converted into a full-scale crash test facility for light aircraft and rotorcraft in the early 1970 s. Since the first full-scale crash test was preformed in February 1974, the IDRF has been used to conduct: 41 full-scale crash tests of General Aviation (GA) aircraft including landmark studies to establish baseline crash performance data for metallic and composite GA aircraft; 11 full-scale crash tests of helicopters including crash qualification tests of the Bell and Sikorsky Advanced Composite Airframe Program (ACAP) prototypes; 48 Wire Strike Protection System (WSPS) qualification tests of Army helicopters; 3 vertical drop tests of Boeing 707 transport aircraft fuselage sections; and, 60+ crash tests of the F-111 crew escape module. For some of these tests, nonlinear transient dynamic codes were utilized to simulate the impact response of the airframe. These simulations were performed to evaluate the capabilities of the analytical tools, as well as to validate the models through test-analysis correlation. In September 2003, NASA Langley closed the IDRF facility and plans are underway to demolish it in 2007. Consequently, it is important to document the contributions made to improve the crashworthiness of light aircraft and rotorcraft achieved through full-scale crash testing and simulation at the IDRF.

  11. Design Challenges Encountered in a Propulsion-Controlled Aircraft Flight Test Program

    NASA Technical Reports Server (NTRS)

    Maine, Trindel; Burken, John; Burcham, Frank; Schaefer, Peter

    1994-01-01

    The NASA Dryden Flight Research Center conducted flight tests of a propulsion-controlled aircraft system on an F-15 airplane. This system was designed to explore the feasibility of providing safe emergency landing capability using only the engines to provide flight control in the event of a catastrophic loss of conventional flight controls. Control laws were designed to control the flightpath and bank angle using only commands to the throttles. Although the program was highly successful, this paper highlights some of the challenges associated with using engine thrust as a control effector. These challenges include slow engine response time, poorly modeled nonlinear engine dynamics, unmodeled inlet-airframe interactions, and difficulties with ground effect and gust rejection. Flight and simulation data illustrate these difficulties.

  12. Energy efficient transport technology: Program summary and bibliography

    NASA Technical Reports Server (NTRS)

    Middleton, D. B.; Bartlett, D. W.; Hood, R. V.

    1985-01-01

    The Energy Efficient Transport (EET) Program began in 1976 as an element of the NASA Aircraft Energy Efficiency (ACEE) Program. The EET Program and the results of various applications of advanced aerodynamics and active controls technology (ACT) as applicable to future subsonic transport aircraft are discussed. Advanced aerodynamics research areas included high aspect ratio supercritical wings, winglets, advanced high lift devices, natural laminar flow airfoils, hybrid laminar flow control, nacelle aerodynamic and inertial loads, propulsion/airframe integration (e.g., long duct nacelles) and wing and empennage surface coatings. In depth analytical/trade studies, numerous wind tunnel tests, and several flight tests were conducted. Improved computational methodology was also developed. The active control functions considered were maneuver load control, gust load alleviation, flutter mode control, angle of attack limiting, and pitch augmented stability. Current and advanced active control laws were synthesized and alternative control system architectures were developed and analyzed. Integrated application and fly by wire implementation of the active control functions were design requirements in one major subprogram. Additional EET research included interdisciplinary technology applications, integrated energy management, handling qualities investigations, reliability calculations, and economic evaluations related to fuel savings and cost of ownership of the selected improvements.

  13. Improved Seals for High Temperature Airframe Applications

    NASA Technical Reports Server (NTRS)

    DeMange, Jeffrey J.; Dunlap, Patrick H.; Steinetz, Bruce M.

    2006-01-01

    Current thermal barrier seals, such as those used on the Space Shuttle, are insufficient to fully meet the demands of future hypersonic vehicles and reentry spacecraft. Previous investigations have demonstrated limited usage temperatures, as evidenced by a decreased ability to maintain sealing effectiveness at high temperatures (i.e., inadequate resiliency). In order to improve resiliency at elevated temperatures, Rene 41 (Allvac) was substituted for Inconel X-750 (Special Metals Corp.) as the spring tube material in the existing seal design. A seal construction incorporating the Rene 41 spring tube was fabricated and tested against the baseline Inconel X-750 spring tube seal. Although resiliency improvements were not as dramatic as in previous tests with the spring tubes alone, seals incorporating the Rene 41 spring tube exhibited an average 20 percent resiliency enhancement up to 1750 F when compared to seals containing the Inconel spring tube. In addition, the seals with the Rene 41 spring tubes showed less reduction in resiliency as temperatures increased above 1200 F. Results also indicated the Saffil (Saffil Ltd.) insulation in the core of the seal contributed more to resiliency than previously thought. Leakage data did not demonstrate an improvement with the seal containing the Rene 41 spring tube. However, based upon resiliency results, one could reasonably expect the Rene 41 version of the seal to track gap openings over a wider range. Therefore it would exhibit lower leakage than the Inconel X-750 version as the seal gap opens during a typical mission.

  14. Processing and Properties of Airframe Materials.

    DTIC Science & Technology

    1987-06-01

    macroscopic deformation behavior . Experiments were performed with 7475 Al having various grain sizes. The flow stress vs strain rate behavior for the mixed...59 3.4.2 Fatigue Crack Propagation Behavior ......................... 60 3.4.3 Correlation of Crack Propagation with...87 4.3-11 The computed stress-strain behavior at various strain rates for a bimodal initial grain size. a = 2.5, b = 5 and c. = 4. o is

  15. Engine-Airframe Integration for Rotorcraft.

    DTIC Science & Technology

    1986-05-01

    maximum efficien- cy in terms of the range of inlet to free stream velocity ratio (Vi/Vo) as 0.0 Vi/Vo 6 0.65, within which local velocity gradients...ft r = radius, ft Subscripts a = air i = inner surface 1-9 o = outer surface c = cowl e = engine - = outside or free stream air 1 = inlet stations 2...these limift of L/D , the designer has the option of nozzling the primary exit area to induce a higher pAmary stream momentum, or adding a diffuser

  16. Aerodynamics of Engine-Airframe Interaction

    NASA Technical Reports Server (NTRS)

    Caughey, D. A.

    1986-01-01

    The report describes progress in research directed towards the efficient solution of the inviscid Euler and Reynolds-averaged Navier-Stokes equations for transonic flows through engine inlets, and past complete aircraft configurations, with emphasis on the flowfields in the vicinity of engine inlets. The research focusses upon the development of solution-adaptive grid procedures for these problems, and the development of multi-grid algorithms in conjunction with both, implicit and explicit time-stepping schemes for the solution of three-dimensional problems. The work includes further development of mesh systems suitable for inlet and wing-fuselage-inlet geometries using a variational approach. Work during this reporting period concentrated upon two-dimensional problems, and has been in two general areas: (1) the development of solution-adaptive procedures to cluster the grid cells in regions of high (truncation) error;and (2) the development of a multigrid scheme for solution of the two-dimensional Euler equations using a diagonalized alternating direction implicit (ADI) smoothing algorithm.

  17. Parametric Equations for Estimating Aircraft Airframe Costs

    DTIC Science & Technology

    1976-02-01

    the following cost elements: engineering, tooling , nonrecurring manufacturing labor, recurring manu- facturing labor, nonrecurring manufacturing... TOOLING 23 V. MANUFACTURING LABOR 27 VI. MANUFACTURING MATERIALS 31 VII. FLIGHT TEST 36 VIII. QUALITY CONTROL 38 IX. TOTAL COST 40 X. OTHER...man-hours are higher than they would be under normal conditions. In anticipating a high produc- tion rate a contractor may expend many more tooling

  18. Improved Durability Aluminium Alloys for Airframe Structures

    DTIC Science & Technology

    2000-04-01

    propagation. ,° " Sensitivity to IGC itself is a purely electrochemical C phenomenon (see e.g.1 ,2) determined by the existence of a " , microgalvanic...which is discussed later. S , Beside this main aspect of fatigue, it is necessary to assess the fatigue resistance of the bulk material1 1. Improved...Warner (1994) International patent Kc(MPa4m)* application WO 96/12829. T-L 100 / 150 90 / 130 8 Warner, T J ; Shahani, R A ; Lassince, P ; Raynaud , G M

  19. Airframe noise measurements by acoustic imaging

    NASA Technical Reports Server (NTRS)

    Kendall, J. M.

    1977-01-01

    Studies of the noise produced by flow past wind tunnel models are presented. The central objective of these is to find the specific locations within a flow which are noisy, and to identify the fluid dynamic processes responsible, with the expectation that noise reduction principles will be discovered. The models tested are mostly simple shapes which result in types of flow that are similar to those occurring on, for example, aircraft landing gear and wheel cavities. A model landing gear and a flap were also tested. Turbulence has been intentionally induced as appropriate in order to simulate full-scale effects more closely. The principal technique involves use of a highly directional microphone system which is scanned about the flow field to be analyzed. The data so acquired are presented as a pictorial image of the noise source distribution. An important finding is that the noise production is highly variable within a flow field and that sources can be attributed to various fluid dynamic features of the flow. Flow separation was not noisy, but separation closure usually was.

  20. Third Generation RLV Structural Seal Development Programs at NASA GRC

    NASA Astrophysics Data System (ADS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.

    2002-10-01

    NASA GRC's work on high temperature structural seal development began in the late 1980's and early 1990's under the NASP (National Aero-Space Plane) project. Bruce Steinetz led the in-house propulsion system seal development program and oversaw industry efforts for propulsion system and airframe seal development for this vehicle. a propulsion system seal location in the NASP engine is shown. The seals were located along the edge of a movable panel in the engine to seal the gap between the panel and adjacent engine sidewalls. More recently, we worked with Rocketdyne on high temperature seals for the linear aerospike engine ramps. In applications such as the former X-33 program, multiple aerospike engine modules would be installed side by side on the vehicle. Seals are required in between adjacent engine modules along the edges and base of the engines. The seals have to withstand the extreme temperatures produced byt he thrusters at the top of the ramps while accommodating large deflections between adjacent ramps. We came up with several promising seal concepts for this application and shared them with Rocketdyne.

  1. The Hyper-X Flight Systems Validation Program

    NASA Technical Reports Server (NTRS)

    Redifer, Matthew; Lin, Yohan; Bessent, Courtney Amos; Barklow, Carole

    2007-01-01

    For the Hyper-X/X-43A program, the development of a comprehensive validation test plan played an integral part in the success of the mission. The goal was to demonstrate hypersonic propulsion technologies by flight testing an airframe-integrated scramjet engine. Preparation for flight involved both verification and validation testing. By definition, verification is the process of assuring that the product meets design requirements; whereas validation is the process of assuring that the design meets mission requirements for the intended environment. This report presents an overview of the program with emphasis on the validation efforts. It includes topics such as hardware-in-the-loop, failure modes and effects, aircraft-in-the-loop, plugs-out, power characterization, antenna pattern, integration, combined systems, captive carry, and flight testing. Where applicable, test results are also discussed. The report provides a brief description of the flight systems onboard the X-43A research vehicle and an introduction to the ground support equipment required to execute the validation plan. The intent is to provide validation concepts that are applicable to current, follow-on, and next generation vehicles that share the hybrid spacecraft and aircraft characteristics of the Hyper-X vehicle.

  2. Hyper-X Engine Design and Ground Test Program

    NASA Technical Reports Server (NTRS)

    Voland, R. T.; Rock, K. E.; Huebner, L. D.; Witte, D. W.; Fischer, K. E.; McClinton, C. R.

    1998-01-01

    The Hyper-X Program, NASA's focused hypersonic technology program jointly run by NASA Langley and Dryden, is designed to move hypersonic, air-breathing vehicle technology from the laboratory environment to the flight environment, the last stage preceding prototype development. The Hyper-X research vehicle will provide the first ever opportunity to obtain data on an airframe integrated supersonic combustion ramjet propulsion system in flight, providing the first flight validation of wind tunnel, numerical and analytical methods used for design of these vehicles. A substantial portion of the integrated vehicle/engine flowpath development, engine systems verification and validation and flight test risk reduction efforts are experimentally based, including vehicle aeropropulsive force and moment database generation for flight control law development, and integrated vehicle/engine performance validation. The Mach 7 engine flowpath development tests have been completed, and effort is now shifting to engine controls, systems and performance verification and validation tests, as well as, additional flight test risk reduction tests. The engine wind tunnel tests required for these efforts range from tests of partial width engines in both small and large scramjet test facilities, to tests of the full flight engine on a vehicle simulator and tests of a complete flight vehicle in the Langley 8-Ft. High Temperature Tunnel. These tests will begin in the summer of 1998 and continue through 1999. The first flight test is planned for early 2000.

  3. Propulsion Induced Effects Test Program

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina; Won, Mark; Bencze, Dan

    1999-01-01

    The objective of this milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane and design variations through computational analysis and experimental subsonic through supersonic wind tunnel testing. The Milestone will generate a comprehensive CFD and wind tunnel data base of the baseline, and design variations. Emphasis will be placed on establishing the propulsion induced effects on the flight performance of the Technology Concept Airplane with all appropriate wind tunnel corrections.

  4. Postsecondary Programs.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 2002

    2002-01-01

    This article lists postsecondary programs specifically for people with deafness and other postsecondary programs with supportive services for students with deafness. Alphabetized by state, contact information is provided for each of the programs, along with date the program was founded, programs, degrees, and number of students and staff with…

  5. Summer Programs

    ERIC Educational Resources Information Center

    Schumann, Herbert

    1975-01-01

    Summer employment and participation in professional programs offer the vocational agriculture teacher the unique opportunity to attain excellence in his program. Most administrators appreciate the teacher's efforts and the resulting well-planned and implemented programs. (MW)

  6. High-speed civil transport issues and technology program

    NASA Technical Reports Server (NTRS)

    Hewett, Marle D.

    1992-01-01

    A strawman program plan is presented, consisting of technology developments and demonstrations required to support the construction of a high-speed civil transport. The plan includes a compilation of technology issues related to the development of a transport. The issues represent technical areas in which research and development are required to allow airframe manufacturers to pursue an HSCT development. The vast majority of technical issues presented require flight demonstrated and validated solutions before a transport development will be undertaken by the industry. The author believes that NASA is the agency best suited to address flight demonstration issues in a concentrated effort. The new Integrated Test Facility at NASA Dryden Flight Research Facility is considered ideally suited to the task of supporting ground validations of proof-of-concept and prototype system demonstrations before night demonstrations. An elaborate ground hardware-in-the-loop (iron bird) simulation supported in this facility provides a viable alternative to developing an expensive fill-scale prototype transport technology demonstrator. Drygen's SR-71 assets, modified appropriately, are a suitable test-bed for supporting flight demonstrations and validations of certain transport technology solutions. A subscale, manned or unmanned flight demonstrator is suitable for flight validation of transport technology solutions, if appropriate structural similarity relationships can be established. The author contends that developing a full-scale prototype transport technology demonstrator is the best alternative to ensuring that a positive decision to develop a transport is reached by the United States aerospace industry.

  7. Gifted Programs.

    ERIC Educational Resources Information Center

    Daniel, Neil; And Others

    1979-01-01

    Three programs for gifted students are described: a 2-week publication arts project; a summer science enrichment program; and a consortium. Note: Article includes: "Risks and Results: A Summer Program on Publication Arts" (Neil Daniel); "Summer Science Program at Appalachian State University" (John Tashner, Richard Stahl, and Debby Carr);…

  8. Adventure Programming.

    ERIC Educational Resources Information Center

    Metcalfe, John A.

    Summarizing the historical development of Adventure Education concepts and programs, this publication describes past and present programs and presents suggestions relative to future programming. Specifically, the following are discussed: (1) Informal Education Programs (Outward Bound; the National Outdoor Leadership School; and other informal…

  9. Collaborative research on V/STOL control system/cockpit display tradeoffs under the NASA/MOD joint aeronautical program

    NASA Technical Reports Server (NTRS)

    Franklin, J. A.; Nicholas, O. P.

    1992-01-01

    Summarized here are activities that have taken place from 1979 to the present in a collaborative program between NASA Ames Research Center and the Royal Aerospace Establishment (now Defence Research Agency), Bedford on flight control system and cockpit display tradeoffs for low-speed and hover operations of future V/STOL aircraft. This program was created as Task 8A of the Joint Aeronautical Program between NASA in the United States and the Ministry of Defence (Procurement Executive) in the United Kingdom. The program was initiated based on a recognition by both parties of the strengths of the efforts of their counterparts and a desire to participate jointly in future simulation and flight experiments. In the ensuing years, teams of NASA and RAE engineers and pilots have participated in each other's simulation experiments to evaluate control and display concepts and define design requirements for research aircraft. Both organizations possess Harrier airframes that have undergone extensive modification to provide in-flight research capabilities in the subject areas. Both NASA and RAE have profited by exchanges of control/display concepts, design criteria, fabrication techniques, software development and validation, installation details, and ground and flight clearance techniques for their respective aircraft. This collaboration has permitted the two organizations to achieve jointly substantially more during the period than if they had worked independently. The two organizations are now entering the phase of flight research for the collaborative program as currently defined.

  10. Program Review.

    ERIC Educational Resources Information Center

    Triton Coll., River Grove, IL.

    Triton College's proposed method of conducting periodic comprehensive evaluations of the quality and potential of its academic programs has five components. First, a self-study is conducted by the faculty and administrators of the program being reviewed, in a year-long comprehensive examination of the program. Second, an external consultant, with…

  11. MEXUS Program.

    ERIC Educational Resources Information Center

    Branan, Alvord; Hergert, Michael

    The MEXUS program, a transnational, undergraduate, dual-degree program in the United States and Mexico, addresses the problem of how universities can better prepare students to manage business in an interdependent global marketplace. The program was initiated as a consortium of four institutions (San Diego State University and Southwestern College…

  12. Gifted Programs.

    ERIC Educational Resources Information Center

    Luehning, Barbara

    1979-01-01

    Describes programs for the gifted: visual and performing arts for secondary students, enrichment for rural elementary students, and a learning center elementary enrichment program. NOTE: includes "INTERARTS: The High School Program for the Talented in the Arts" by Barbara Luehning, "Spice" by Jane V. Salisbury, and "Learning Center Enrichment…

  13. Cultural Voucher Program; Program Abstract.

    ERIC Educational Resources Information Center

    Museums Collaborative, Inc., New York, NY.

    A description of the Museums Collaborative Voucher Program, a system through which cultural institutions conduct programs with large, heterogeneous, adult populations in New York City is provided in this paper. The program began with two goals: to broaden the audience served by New York City's cultural institutions and to provide the institutions…

  14. 1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

    NASA Technical Reports Server (NTRS)

    McMillin, S. Naomi (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

  15. 1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    McMillin, S. Naomi (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

  16. Contributions to Active Buffeting Alleviation Programs by the NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    1999-01-01

    Buffeting is an aeroelastic phenomenon which plagues high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. This buffeting is a concern from fatigue and inspection points of view. By means of wind-tunnel and flight tests, this phenomenon is well studied to the point that buffet loads can be estimated and fatigue life can be increased by structural enhancements to the airframe. In more recent years, buffeting alleviation through active control of smart materials has been highly researched in wind-tunnel proof-of-concept demonstrations and full-scale ground tests using the F/A-18 as a test bed. Because the F/A-18 resides in fleets outside as well as inside the United States, these tests have evolved into international collaborative research activities with Australia and Canada, coordinated by the Air Force Research Laboratory (AFRL) and conducted under the auspices of The Technical Cooperation Program (TTCP). With the recent successes and advances in smart materials, the main focus of these buffeting alleviation tests has also evolved to a new level: utilize the F/A-18 as a prototype to mature smart materials for suppressing vibrations of aerospace structures. The role of the NASA Langley Research Center (LaRC) in these programs is presented.

  17. NASA Langley Research Center's Contributions to International Active Buffeting Alleviation Programs

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    2000-01-01

    Buffeting is an aeroelastic phenomenon which plagues high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. This buffeting is a concern from fatigue and inspection points of view. By means of wind-tunnel and flight tests, this phenomenon is well studied to the point that buffet loads can be estimated and fatigue life can be increased by structural enhancements to the airframe. In more recent years, buffeting alleviation through active control of smart materials has been highly researched in wind-tunnel proof-of-concept demonstrations and full-scale ground tests using the F/A-18 as a test bed. Because the F/A-18 resides in fleets outside as well as inside the United States, these tests have evolved into international collaborative research activities with Australia and Canada, coordinated by the Air Force Research Laboratory (AFRL) and conducted under the auspices of The Technical Cooperation Program (TTCP). With the recent successes and advances in smart materials, the main focus of these buffeting alleviation tests has also evolved to a new level: utilize the F/A-18 as a prototype to mature smart materials for suppressing vibrations of aerospace structures. The role of the NASA Langley Research Center (LaRC) in these programs is presented.

  18. Experience with Ada on the F-18 High Alpha Research Vehicle flight test program

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria A.; Earls, Michael; Le, Jeanette; Thomson, Michael

    1994-01-01

    Considerable experience has been acquired with Ada at the NASA Dryden Flight Research Facility during the on-going High Alpha Technology Program. In this program, an F-18 aircraft has been highly modified by the addition of thrust-vectoring vanes to the airframe. In addition, substantial alteration was made in the original quadruplex flight control system. The result is the High Alpha Research Vehicle. An additional research flight control computer was incorporated in each of the four channels. Software for the research flight control computer was written Ada. To date, six releases of this software have been flown. This paper provides a detailed description of the modifications to the research flight control system. Efficient ground-testing of the software was accomplished by using simulations that used the Ada for portions of their software. These simulations are also described. Modifying and transferring the Ada flight software to the software simulation configuration has allowed evaluation of this language. This paper also discusses such significant issues in using Ada as portability, modifiability, and testability as well as documentation requirements.

  19. A unified approach for composite cost reporting and prediction in the ACT program

    NASA Technical Reports Server (NTRS)

    Freeman, W. Tom; Vosteen, Louis F.; Siddiqi, Shahid

    1991-01-01

    The Structures Technology Program Office (STPO) at NASA Langley Research Center has held two workshops with representatives from the commercial airframe companies to establish a plan for development of a standard cost reporting format and a cost prediction tool for conceptual and preliminary designers. This paper reviews the findings of the workshop representatives with a plan for implementation of their recommendations. The recommendations of the cost tracking and reporting committee will be implemented by reinstituting the collection of composite part fabrication data in a format similar to the DoD/NASA Structural Composites Fabrication Guide. The process of data collection will be automated by taking advantage of current technology with user friendly computer interfaces and electronic data transmission. Development of a conceptual and preliminary designers' cost prediction model will be initiated. The model will provide a technically sound method for evaluating the relative cost of different composite structural designs, fabrication processes, and assembly methods that can be compared to equivalent metallic parts or assemblies. The feasibility of developing cost prediction software in a modular form for interfacing with state of the art preliminary design tools and computer aided design (CAD) programs is assessed.

  20. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 1 publication covers configuration aerodynamics.

  1. DC-9 Flight Demonstration Program with Refanned JT8D Engines. Volume 3; Performance and Analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The JT8D-109 engine has a sea level static, standard day bare engine takeoff thrust of 73,840 N. At sea level standard day conditions the additional thrust of the JT8D-109 results in 2,040 kg additional takeoff gross weight capability for a given field length. Range loss of the DC-9 Refan airplane for long range cruise was determined. The Refan airplane demonstrated stall, static longitudinal stability, longitudinal control, longitudinal trim, minimum control speeds, and directional control characteristics similar to the DC-9-30 production airplane and complied with airworthiness requirements. Cruise, climb, and thrust reverser performance were evaluated. Structural and dynamic ground test, flight test and analytical results substantiate Refan Program requirements that the nacelle, thrust reverser hardware, and the airplane structural modifications are flightworthy and certifiable and that the airplane meets flutter speed margins. Estimated unit cost of a DC-9 Refan retrofit program is 1.338 million in mid-1975 dollars with about an equal split in cost between airframe and engine.

  2. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among die scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 2/Part 2 publication covers the tools and methods development session.

  3. Experience with Ada on the F-18 High Alpha Research Vehicle Flight Test Program

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria A.; Earls, Michael; Le, Jeanette; Thomson, Michael

    1992-01-01

    Considerable experience was acquired with Ada at the NASA Dryden Flight Research Facility during the on-going High Alpha Technology Program. In this program, an F-18 aircraft was highly modified by the addition of thrust-vectoring vanes to the airframe. In addition, substantial alteration was made in the original quadruplex flight control system. The result is the High Alpha Research Vehicle. An additional research flight control computer was incorporated in each of the four channels. Software for the research flight control computer was written in Ada. To date, six releases of this software have been flown. This paper provides a detailed description of the modifications to the research flight control system. Efficient ground-testing of the software was accomplished by using simulations that used the Ada for portions of their software. These simulations are also described. Modifying and transferring the Ada for flight software to the software simulation configuration has allowed evaluation of this language. This paper also discusses such significant issues in using Ada as portability, modifiability, and testability as well as documentation requirements.

  4. 1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    McMillin, S. Naomi (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry HighSpeed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of. Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

  5. 1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

    NASA Technical Reports Server (NTRS)

    Hahne, David E. (Editor)

    1999-01-01

    NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 2 publication covers the design optimization and testing sessions.

  6. Aviation Safety Program Atmospheric Environment Safety Technologies (AEST) Project

    NASA Technical Reports Server (NTRS)

    Colantonio, Ron

    2011-01-01

    Engine Icing: Characterization and Simulation Capability: Develop knowledge bases, analysis methods, and simulation tools needed to address the problem of engine icing; in particular, ice-crystal icing Airframe Icing Simulation and Engineering Tool Capability: Develop and demonstrate 3-D capability to simulate and model airframe ice accretion and related aerodynamic performance degradation for current and future aircraft configurations in an expanded icing environment that includes freezing drizzle/rain Atmospheric Hazard Sensing and Mitigation Technology Capability: Improve and expand remote sensing and mitigation of hazardous atmospheric environments and phenomena

  7. Logic programming

    SciTech Connect

    Lusk, E.L.; Overbeek, R.A.

    1989-01-01

    This book contains the proceedings of the 1989 North American Conference on Logic Programming. Included are the following papers: Expanding query power in constrain logic programming languages, Investigating the linguistics of DNA with definite clause grammars, An intermediate language to support prolog's unification.

  8. Gifted Programs.

    ERIC Educational Resources Information Center

    Roeper Review, 1979

    1979-01-01

    Descriptions of four gifted programs are offered in articles titled "Career Education for Gifted Students in Illinois" (J. Ellis and B. Ford); "Interage Program for Critical Thinking" (H. Masterson); "Talcott Mountain Science Center" (D. LaSalle); and "Project L.O.G.I.C.--Nurturing the Mathematically Gifted" (W. Foley and B. Spack). (SBH)

  9. Promising Programs.

    ERIC Educational Resources Information Center

    Tindall, Lloyd W.; Hedberg, Sally B.

    Benefits to disabled participants of programs funded by the Job Training Partnership Act (JTPA) are summarized and several JTPA programs highlighted. Common services included vocational assessment, work experience, career exploration, on-the-job training, vocational training, job placement, job counseling, job seeking, and job keeping. The Special…

  10. Computer Programs.

    ERIC Educational Resources Information Center

    Anderson, Tiffoni

    This module provides information on development and use of a Material Safety Data Sheet (MSDS) software program that seeks to link literacy skills education, safety training, and human-centered design. Section 1 discusses the development of the software program that helps workers understand the MSDSs that accompany the chemicals with which they…

  11. Adventure Programming.

    ERIC Educational Resources Information Center

    Miles, John C., Ed.; Priest, Simon, Ed.

    Adventure programming is the deliberate use of adventurous experiences to create learning in individuals or groups, often with the goal of improving society or communities. Adventure programming may focus on recreation, education, individual or group development, or therapy, or on a combination of these. This second edition contains 61 chapters by…

  12. Program Listings.

    ERIC Educational Resources Information Center

    Journal of Computers in Mathematics and Science Teaching, 1983

    1983-01-01

    A complete listing of a projectile motion program for the Apple II microcomputer is provided. A discussion of this computer simulation and a table with variables used in the program (as well as their meanings) can be found in SE 533 596. (JN)

  13. Postsecondary Programs.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 2003

    2003-01-01

    This listing provides directory information on U.S. postsecondary schools specifically for people who are deaf and other postsecondary programs with supportive services for students with deafness. Schools and programs are listed by state and information is provided on the number of students with deafness enrolled, degrees offered, and special…

  14. Programming Languages.

    ERIC Educational Resources Information Center

    Tesler, Lawrence G.

    1984-01-01

    Discusses the nature of programing languages, considering the features of BASIC, LOGO, PASCAL, COBOL, FORTH, APL, and LISP. Also discusses machine/assembly codes, the operation of a compiler, and trends in the evolution of programing languages (including interest in notational systems called object-oriented languages). (JN)

  15. Dynamic programming.

    PubMed

    Nalbantoğlu, Ö Ufuk

    2014-01-01

    Independent scoring of the aligned sections to determine the quality of biological sequence alignments enables recursive definitions of the overall alignment score. This property is not only biologically meaningful but it also provides the opportunity to find the optimal alignments using dynamic programming-based algorithms. Dynamic programming is an efficient problem solving technique for a class of problems that can be solved by dividing into overlapping subproblems. Pairwise sequence alignment techniques such as Needleman-Wunsch and Smith-Waterman algorithms are applications of dynamic programming on pairwise sequence alignment problems. These algorithms offer polynomial time and space solutions. In this chapter, we introduce the basic dynamic programming solutions for global, semi-global, and local alignment problems. Algorithmic improvements offering quadratic-time and linear-space programs and approximate solutions with space-reduction and seeding heuristics are discussed. We finally introduce the application of these techniques on multiple sequence alignment briefly.

  16. Programming models

    SciTech Connect

    Daniel, David J; Mc Pherson, Allen; Thorp, John R; Barrett, Richard; Clay, Robert; De Supinski, Bronis; Dube, Evi; Heroux, Mike; Janssen, Curtis; Langer, Steve; Laros, Jim

    2011-01-14

    A programming model is a set of software technologies that support the expression of algorithms and provide applications with an abstract representation of the capabilities of the underlying hardware architecture. The primary goals are productivity, portability and performance.

  17. SPOT Program

    NASA Technical Reports Server (NTRS)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; Zimmerman, Patrick L.; Khatri, Reshma

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  18. Fundamental Aeronautics Program: Overview of Propulsion Work in the Supersonic Cruise Efficiency Technical Challenge

    NASA Technical Reports Server (NTRS)

    Castner, Ray

    2012-01-01

    The Supersonics Project, part of NASA's Fundamental Aeronautics Program, contains a number of technical challenge areas which include sonic boom community response, airport noise, high altitude emissions, cruise efficiency, light weight durable engines/airframes, and integrated multi-discipline system design. This presentation provides an overview of the current (2012) activities in the supersonic cruise efficiency technical challenge, and is focused specifically on propulsion technologies. The intent is to develop and validate high-performance supersonic inlet and nozzle technologies. Additional work is planned for design and analysis tools for highly-integrated low-noise, low-boom applications. If successful, the payoffs include improved technologies and tools for optimized propulsion systems, propulsion technologies for a minimized sonic boom signature, and a balanced approach to meeting efficiency and community noise goals. In this propulsion area, the work is divided into advanced supersonic inlet concepts, advanced supersonic nozzle concepts, low fidelity computational tool development, high fidelity computational tools, and improved sensors and measurement capability. The current work in each area is summarized.

  19. Fundamental Aeronautics Program: Overview of Project Work in Supersonic Cruise Efficiency

    NASA Technical Reports Server (NTRS)

    Castner, Raymond

    2011-01-01

    The Supersonics Project, part of NASA?s Fundamental Aeronautics Program, contains a number of technical challenge areas which include sonic boom community response, airport noise, high altitude emissions, cruise efficiency, light weight durable engines/airframes, and integrated multi-discipline system design. This presentation provides an overview of the current (2011) activities in the supersonic cruise efficiency technical challenge, and is focused specifically on propulsion technologies. The intent is to develop and validate high-performance supersonic inlet and nozzle technologies. Additional work is planned for design and analysis tools for highly-integrated low-noise, low-boom applications. If successful, the payoffs include improved technologies and tools for optimized propulsion systems, propulsion technologies for a minimized sonic boom signature, and a balanced approach to meeting efficiency and community noise goals. In this propulsion area, the work is divided into advanced supersonic inlet concepts, advanced supersonic nozzle concepts, low fidelity computational tool development, high fidelity computational tools, and improved sensors and measurement capability. The current work in each area is summarized.

  20. Hyper-X Research Vehicle (HXRV) Experimental Aerodynamics Test Program Overview

    NASA Technical Reports Server (NTRS)

    Holland, Scott D.; Woods, William C.; Engelund, Walter C.

    2000-01-01

    This paper provides an overview of the experimental aerodynamics test program to ensure mission success for the autonomous flight of the Hyper-X Research Vehicle (HXRV). The HXRV is a 12-ft long, 2700 lb lifting body technology demonstrator designed to flight demonstrate for the first time a fully airframe integrated scramjet propulsion system. Three flights are currently planned, two at Mach 7 and one at Mach 10, beginning in the fall of 2000. The research vehicles will be boosted to the prescribed scramjet engine test point where they will separate from the booster, stabilize, and initiate engine test. Following 5+ seconds of powered flight and 15 seconds of cow-open tares, the cowl will close and the vehicle will fly a controlled deceleration trajectory which includes numerous control doublets for in-flight aerodynamic parameter identification. This paper reviews the preflight testing activities, wind tunnel models, test rationale, risk reduction activities, and sample results from wind tunnel tests supporting the flight trajectory of the HXRV from hypersonic engine test point through subsonic flight termination.

  1. Design challenges encountered in the F-15 PCA flight test program

    NASA Technical Reports Server (NTRS)

    Maine, Trindel A.; Burcham, Frank W., Jr.; Schaefer, Peter; Burken, John

    1995-01-01

    The NASA Dryden Flight Research Center conducted flight tests of a propulsion-controlled aircraft system on an F-15 airplane. This system was designed to explore the feasibility of providing safe emergency landing capability using only the engines to provide flight control in the event of a catastrophic loss of conventional flight controls. Control laws were designed to control the flight path and bank angle using only commands to the throttles. While the program was highly successful, this paper concentrates on the challenges encountered using engine thrust as the only control effector. Compared to conventional flight control surfaces, the engines are slow, nonlinear, and have limited control effectiveness. This increases the vulnerability of the system to outside disturbances and changes in aerodynamic conditions. As a result, the PCA system had problems with gust rejection. Cross coupling of the longitudinal and lateral axis also occured, primarily as a result of control saturation. The normally negligible effects of inlet airframe interactions became significant with the engines as the control effector. Flight and simulation data are used to illustrate these difficulties.

  2. GASP- General Aviation Synthesis Program. Volume 5: Weight

    NASA Technical Reports Server (NTRS)

    Hague, D.

    1978-01-01

    Subroutines for determining the weights of propulsion system related components and the airframe components of an aircraft configuration are presented. Subroutines that deal with design load conditions, aircraft balance, and tail sizing are included. Options for turbine and internal combustion engines are provided.

  3. Aircraft noise prediction program theoretical manual, part 2

    NASA Technical Reports Server (NTRS)

    Zorumski, W. E.

    1982-01-01

    Detailed prediction methods for specific aircraft noise sources are given. These sources are airframe noise, combustion noise, fan noise, single and dual stream jet noise, and turbine noise. Modifications to the NASA methods which comply with the International Civil Aviation Organization standard method for aircraft noise prediction are given.

  4. NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr.

    1993-01-01

    This report on the NASA-UVa Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from January 1, 1992 to June 30, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) powder metallurgy 2XXX alloys, (3) rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  5. Subjunctive Program.

    ERIC Educational Resources Information Center

    Newkumet, Robyn

    A self-instructional program in the French subjunctive mood is organized by categories of verbs requiring the subjunctive. Within each category, directions are given for using the verbs, and exercises are prescribed with sample sentences. The exercises consist of pattern drills and translations. A post-test is included. (MSE)

  6. Parkway Program.

    ERIC Educational Resources Information Center

    Philadelphia School District, PA.

    The Parkway Program was designed to investigate the possibility that a high school could be organized independently of any fixed institutional facilities, whether these be a school building or a fixed faculty. One hundred and forty-three Philadelphia High School students were selected at random from among applicants representing all eight…

  7. Summer Programs.

    ERIC Educational Resources Information Center

    Toussaint, Isabella H.

    An intensive 6-week summer readiness program held in the Beaver Area School District, Beaver, Pennsylvania, developed linguistic facility among 15 preschool children. Daily activities included discussion, picture study, creative arts, field trips, developing experience charts, and other nonlanguage arts activities. A combined experiential,…

  8. Program Proposal

    ERIC Educational Resources Information Center

    Baskas, Richard S.

    2012-01-01

    A study was conducted to determine if a deficiency, or learning gap, existed in a particular working environment. To determine if an assessment was to be conducted, a program proposal would need to be developed to explore this situation. In order for a particular environment to react and grow with other environments, it must be able to take on…

  9. Basal Programs.

    ERIC Educational Resources Information Center

    Curriculum Review, 1978

    1978-01-01

    Products evaluated in this column are two readiness kits: Readiness Steps (Houghton Mifflin) and Experiences in Reading Readiness (Milton Bradley) plus three text series for the full elementary grade span: Pathfinders (Allyn and Bacon); American Book Reading Program (American Book Company); and Young America Basic Series (Rand McNally). (SJL)

  10. Program Development

    SciTech Connect

    Atencio, Julian J.

    2014-05-01

    This presentation covers how to go about developing a human reliability program. In particular, it touches on conceptual thinking, raising awareness in an organization, the actions that go into developing a plan. It emphasizes evaluating all positions, eliminating positions from the pool due to mitigating factors, and keeping the process transparent. It lists components of the process and objectives in process development. It also touches on the role of leadership and the necessity for audit.

  11. Relational Programming.

    DTIC Science & Technology

    1983-09-01

    EXERCISES: Factor V out of the definition of join. 13. Aucestral Dilationu 13.1 denfimkon Carnap [Carnap58] defines the relation of a property p...the utrueture function Carnap [Carnap58] defines two relations to be isomorphic when there is a biunivalent relation between their members that...its algebra of programs, CACM 21, 8 (August 1978), 613-641. [Carnap58] Carnap , R. Introduction to Synbolic Logic and its Appications, Dover, 1958

  12. Libraries program

    USGS Publications Warehouse

    2011-01-01

    The U.S. Congress authorized a library for the U.S. Geological Survey (USGS) in 1879. The library was formally established in 1882 with the naming of the first librarian and began with a staff of three and a collection of 1,400 books. Today, the USGS Libraries Program is one of the world's largest Earth and natural science repositories and a resource of national significance used by researchers and the public worldwide.

  13. AWARD program

    NASA Astrophysics Data System (ADS)

    Leppert, Frank

    1998-07-01

    The All Weather ARrival and Departure (AWARD) program is supported by the European Commission under the Brite-EuRam III structure. Following the VERSATILE preparation program, it started on June 1996 and is planned to finish end of 1999. The program consortium consists of ten partners such as a major airline, aircraft and equipment manufacturers, research and tests centers, and an university. Contractors from France, Germany, Great Britain, Italy and The Netherlands are coordinated by Sextant Avionique. AWARD main objective is to demonstrate the efficiency of vision systems under adverse weather conditions. In order to evaluate the added benefits of these concepts within aircraft operations of approach, landing, taxi and takeoff, two applications are developed: (1) Enhanced Vision System (EVS) based on Head Up Display enhancement with Forward Looking Infrared (FLIR) and Millimeter Wave Radar (MMWR) images. (2) Synthetic Vision System (SVS) displaying an overlaid symbology on a perspective presentation of the environment, thanks to the combination of database and accurate positioning systems. The evaluation of these two tests systems will focus on: (1) Performance and human acceptability aspects. They will be appreciated according to human factors criteria as well as an integration within realistic environments. The NLR Research Flight Simulator and the DLR ATTAS flight test aircraft will be used. (2) Reliability, integrity aspects thanks to a theoretical certification/system study which will propose guidelines for certification, and will address impact on the system architecture. The paper addresses the work structure of AWARD in order to show what are the keypoints addressed in this program.

  14. Robot Programming.

    DTIC Science & Technology

    1982-12-01

    8217AD-A127 233 ROBOT PROGRRMMING(U) MASSACHUSETTS INST OFGTECHi/ CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB T LOZANO-PEREZ UNCLASSIFIED DC8 AI-9 N884...CATALOG NUMBER * a ~AIM 698 R a is 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Robot Programming Memorandum 6. PERFORMING ORG. REPORT...34R Distribution is Unlimted .. SUPPLEMENTARY NOTES None 1. KEY WORDS (Continue on r verea aide ii neeaortm and Identify by block number) *Q. Robotics

  15. Baseline program

    NASA Technical Reports Server (NTRS)

    Roberts, Barney B.; Vonputtkamer, Jesco

    1992-01-01

    This assumed program was developed from several sources of information and is extrapolated over future decades using a set of reasonable assumptions based on incremental growth. The assumptions for the NASA baseline program are as follows: balanced emphasis in four domains; a constant level of activity; low to moderate real budget growth; maximum use of commonality; and realistic and practical technology development. The first domain is low Earth Orbit (LEO). Activities there are concentrated on the space station but extend on one side to Earth-pointing sensors for unmanned platforms and on the other to the launch and staging of unmanned solar system exploration missions. The second domain is geosynchronous Earth orbit (GEO) and cislunar space. Activities here include all GEO missions and operations, both unmanned and manned, and all transport of materials and crews between LEO and the vicinity of the Moon. The third domain is the Moon itself. Lunar activities are to include both orbiting and landing missions; the landings may be either unmanned or manned. The last domain is Mars. Missions to Mars will initially be unmanned but they will eventually be manned. Program elements and descriptions are discussed as are critiques of the NASA baseline.

  16. Ada concurrent programming

    SciTech Connect

    Gehani, N.

    1984-01-01

    In this book, Narain Gehani explains the concurrent programming facilities in Ada and shows how to use them effectively in writing concurrent programs. He also surveys concurrent programming facilities in other languages, discusses issues specific to concurrent programming, and examines the limitations of the concurrent programming facilities in Ada. Topics considered include an introduction to concurrent programming, the concurrent programming model in Ada, and a survey of other concurrent programming models; tasking, i.e., concurrent programming facilities in Ada; task types; exceptions and tasking; device drivers; real-time programming; topics related to concurrent programming; more examples of concurrent programming; and synopsis of sequential programming in Ada.

  17. Educational Programs and Services.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1989

    1989-01-01

    Listed are over 1,000 programs for the deaf including preschool through secondary schools and classes in the U.S. and Canada, postsecondary programs, teacher training programs, programs for professional specialists, programs for training interpreters for the deaf, programs for the deaf-blind, the Helen Keller National Center, and programs for…

  18. The MSFC Program Control Development Program

    NASA Technical Reports Server (NTRS)

    1994-01-01

    It is the policy of the Marshall Space Flight Center (MSFC) that employees be given the opportunity to develop their individual skills and realize their full potential consistent with their selected career path and with the overall Center's needs and objectives. The MSFC Program Control Development Program has been designed to assist individuals who have selected Program Control or Program Analyst Program Control as a career path to achieve their ultimate career goals. Individuals selected to participate in the MSFC Program Control Development Program will be provided with development training in the various Program Control functional areas identified in the NASA Program Control Model. The purpose of the MSFC Program Control Development Program is to develop individual skills in the various Program Control functions by on-the-job and classroom instructional training on the various systems, tools, techniques, and processes utilized in these areas.

  19. Geothermal Technologies Program Overview - Peer Review Program

    SciTech Connect

    Milliken, JoAnn

    2011-06-06

    This Geothermal Technologies Program presentation was delivered on June 6, 2011 at a Program Peer Review meeting. It contains annual budget, Recovery Act, funding opportunities, upcoming program activities, and more.

  20. HEATKAU Program.

    SciTech Connect

    ELDIN NAFEE, SHERIF SALAH

    2013-07-24

    Version 00 Calculations of the decay heat is of great importance for the design of the shielding of discharged fuel, the design and transport of fuel-storage flasks and the management of the resulting radioactive waste. These are relevant to safety and have large economic and legislative consequences. In the HEATKAU code, a new approach has been proposed to evaluate the decay heat power after a fission burst of a fissile nuclide for short cooling time. This method is based on the numerical solution of coupled linear differential equations that describe decays and buildups of the minor fission products (MFPs) nuclides. HEATKAU is written entirely in the MATLAB programming environment. The MATLAB data can be stored in a standard, fast and easy-access, platform- independent binary format which is easy to visualize.

  1. Telemedicine Program

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Since the 1970s, NASA has been involved in the research and demonstration of telemedicine for its potential in the care of astronauts in flight and Earth-bound applications. A combination of NASA funding, expertise and off-the-shelf computer and networking systems made telemedicine possible for a medically underserved hospital in Texas. Through two-way audio/video relay, the program links pediatric oncology specialists at the University of Texas Health Science Center in San Antonio to South Texas Hospital in Harlingen, providing easier access and better care to children with cancer. Additionally, the hospital is receiving teleclinics on pediatric oncology nursing, family counseling and tuberculosis treatment. VTEL Corporation, Sprint, and the Healthcare Open Systems and Trials Consortium also contributed staff and hardware.

  2. Intrauterine programming

    PubMed Central

    Sedaghat, Katayoun; Zahediasl, Saleh; Ghasemi, Asghar

    2015-01-01

    In mammals, the intrauterine condition has an important role in the development of fetal physiological systems in later life. Suboptimal maternal environment can alter the regulatory pathways that determine the normal development of the fetus in utero, which in post-natal life may render the individual more susceptible to cardiovascular or metabolic adult-life diseases. Changes in the intrauterine availability of nutrients, oxygen and hormones can change the fetal tissue developmental regulatory planning, which occurs genomically and non-genomically and can cause permanent structural and functional changes in the systems, leading to diseases in early years of life and those that particularly become overt in adulthood. In this review we take a brief look at the main elements which program the fetal system development and consequently induce a crucial impact on the cardiovascular, nervous and hormonal systems in adulthood. PMID:25945232

  3. Program Logics for Homogeneous Meta-programming

    NASA Astrophysics Data System (ADS)

    Berger, Martin; Tratt, Laurence

    A meta-program is a program that generates or manipulates another program; in homogeneous meta-programming, a program may generate new parts of, or manipulate, itself. Meta-programming has been used extensively since macros were introduced to Lisp, yet we have little idea how formally to reason about meta-programs. This paper provides the first program logics for homogeneous meta-programming - using a variant of MiniML_e^{square} by Davies and Pfenning as underlying meta-programming language. We show the applicability of our approach by reasoning about example meta-programs from the literature. We also demonstrate that our logics are relatively complete in the sense of Cook, enable the inductive derivation of characteristic formulae, and exactly capture the observational properties induced by the operational semantics.

  4. Engine/airframe compatibility studies for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technology assessment studies were conducted to provide an updated technology base from which an advanced supersonic cruise aircraft can be produced with a high probability of success. An assessment of the gains available through the application of advanced technologies in aerodynamics, propulsion, acoustics, structures, materials, and active controls is developed. The potential market and range requirements as well as economic factors including payload, speed, airline operating costs, and airline profitability are analyzed. The conceptual design of the baseline aircraft to be used in assessing the technology requirements is described.

  5. Numerical Research of Airframe/Engine Integrative Hypersonic Vehicle

    DTIC Science & Technology

    2007-11-02

    paper, an engineering method and a finite volume method based on the center of grid are developed for preliminary research of interested integrative...development of hypersonic technology, advanced experimental, analytical and computational methods are being exploited in the design of hypersonic...configurations to obtain excellent aerodynamic characteristics[5]. Due to the limitation of test capabilities to model all the impossible flight conditions

  6. Application of MEMS Microphone Array Technology to Airframe Noise Measurements

    NASA Technical Reports Server (NTRS)

    Humphreys, William M., Jr.; Shams, Qamar A.; Graves, Sharon S.; Sealey, Bradley S.; Bartram, Scott M.; Comeaux, Toby

    2005-01-01

    Current generation microphone directional array instrumentation is capable of extracting accurate noise source location and directivity data on a variety of aircraft components, resulting in significant gains in test productivity. However, with this gain in productivity has come the desire to install larger and more complex arrays in a variety of ground test facilities, creating new challenges for the designers of array systems. To overcome these challenges, a research study was initiated to identify and develop hardware and fabrication technologies which could be used to construct an array system exhibiting acceptable measurement performance but at much lower cost and with much simpler installation requirements. This paper describes an effort to fabricate a 128-sensor array using commercially available Micro-Electro-Mechanical System (MEMS) microphones. The MEMS array was used to acquire noise data for an isolated 26%-scale high-fidelity Boeing 777 landing gear in the Virginia Polytechnic Institute and State University Stability Tunnel across a range of Mach numbers. The overall performance of the array was excellent, and major noise sources were successfully identified from the measurements.

  7. Advanced Airframe Structural Materials: A Primer and Cost Estimating Methodology

    DTIC Science & Technology

    1991-01-01

    laying machines for larger, mildly con- toured parts such as wing and stabilizer skins. For such parts, automated tape laying machines can operate many...heat guns (90-130°F). However, thermoplastics require as much as 650°F for forming. Automated tape laying machines for these materials use warm...cycles to properly seat the plies onto the tool. This time-consuming process can sometimes be eliminated or reduced by the use of automated tape laying procedures

  8. Superplastic Formed Aluminum Airframe Structures. Volume 1. Executive Summary

    DTIC Science & Technology

    1987-07-01

    Cone Tests ................... 28 3.3 Material Evaluation .................. 32 3.3.1 Cavitation Behavior of 7475 Alloy .... . 33 3.3.2 Mill Produced... 7075 and 7475, have SPF potential after their wrought forms have undergone grain refinement. The grain refinement is achieved through a thermomechanical... 7075 , 7050, 2024, Supral 100, Alcan 08050 25 and powder alloy, X7091 were considered. The three alloys se- lected for preliminary evaluation and a

  9. Computational Evaluation of Airframe Noise Reduction Concepts at Full Scale

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Duda, Benjamin; Hazir, Andreas; Fares, Ehab

    2016-01-01

    High-fidelity simulations focused on full-scale evaluation of new technologies for mitigating flap and landing gear noise are presented. These noise reduction concepts were selected because of their superior acoustic performance, as demonstrated during NASA wind tunnel tests of an 18%-scale, semi-span model of a Gulfstream aircraft. The full-scale, full-aircraft, time-accurate simulations were performed with the lattice Boltzmann PowerFLOW(Registered Trademark) solver for free air at a Mach number of 0.2. Three aircraft configurations (flaps deflected at 39? without and with main gear deployed, and 0? flaps with main gear extended) were used to determine the aero-acoustic performance of the concepts on component-level (individually) and system-level (concurrent applica-tion) bases. Farfield noise spectra were obtained using a Ffowcs-Williams and Hawkings acoustic analogy approach. Comparison of the predicted spectra without (baseline) and with the noise treatments applied showed that noise reduction benefits between 2-3 dB for the flap and 1.3-1.7 dB for the main landing gear are obtained. It was also found that the full extent of the benefits is being masked by the noise generated from the flap brackets and main gear cavities, which act as prominent secondary sources.

  10. Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

    DTIC Science & Technology

    1982-07-01

    VALVE M~l’ ® FE(L FE06Cu~i 5u~jt~~ vat~FUEIL I.AL r(E PUE L FUEL f PUt GE VALVI AADTIV FWWV STAUIFBY Boa 7 HILL~E CAV 38 GAL U JILL ZAM StOOP VCA’r...to FAA. 3. Fiorentino, A., De Saro, R., and Franz , T., An Assessment of the Use Of Antimisting Fuel in Turbofan Engines, United Technologies

  11. Engine/Airframe/Drive Train Dynamic Interface Documentation

    DTIC Science & Technology

    1978-10-01

    in hydraulic system noise reduction. 200 r *r=a r(n 4- -n 0 4J We 4) Q)4J4 t 1 H- e 1 r r-. Wrl0 Ln4-~ .rIniIH .9-i N 0__ _ _ _ _ _ _ V)4J’. 04 0301 ...PAGE N BEFORE COLETWG Fri" 1 . REIORT NUMBER 1 - 2. GOVT ACCESSION N04 3. RE-,IPIENT’S CATALOG NUMBER I.USARTL-TR- 78-15 4. TITI.E (and Subtitle) TYPE Of...as part of an overall Government- 1 effort to define specific areas in which future research funding should b1e placed to develop improved design

  12. Low-frequency noise reduction of lightweight airframe structures

    NASA Technical Reports Server (NTRS)

    Getline, G. L.

    1976-01-01

    The results of an experimental study to determine the noise attenuation characteristics of aircraft type fuselage structural panels were presented. Of particular interest was noise attenuation at low frequencies, below the fundamental resonances of the panels. All panels were flightweight structures for transport type aircraft in the 34,050 to 45,400 kg (75,000 to 100,000 pounds) gross weight range. Test data include the results of vibration and acoustic transmission loss tests on seven types of isotropic and orthotropically stiffened, flat and curved panels. The results show that stiffness controlled acoustically integrated structures can provide very high noise reductions at low frequencies without significantly affecting their high frequency noise reduction capabilities.

  13. Fast simulation method for airframe analysis based on big data

    NASA Astrophysics Data System (ADS)

    Liu, Dongliang; Zhang, Lixin

    2016-10-01

    In this paper, we employ the big data method to structural analysis by considering the correlations between loads and loads, loads and results and results and results. By means of fundamental mathematics and physical rules, the principle, feasibility and error control of the method are discussed. We then establish the analysis process and procedures. The method is validated by two examples. The results show that the fast simulation method based on big data is fast and precise when it is applied to structural analysis.

  14. Feedback strategies for visual search in airframe structural inspection.

    PubMed

    Gramopadhye, A K; Drury, C G; Sharit, J

    1997-05-01

    Feedback of information has consistently shown positive results in human inspection, provided it is given in a timely and appropriate manner. Feedback serves as the basis of most training schemes; traditionally this has been performance feedback. Other forms of feedback which provide strategy information rather than performance information may have a role in improving inspection. This study compared performance feedback and cognitive feedback in a realistic simulation of an aircraft structural inspection task. Performance (time, errors) feedback showed the greatest improvements in performance measures. Cognitive feedback enhanced efficiency measures of search strategy. When cognitive feedback consisted of visual representations of the path and the coverage of the search sequence, subjects also were able to use this task information to improve their search performance.

  15. Superplastic Formed Aluminum Airframe Structures. Volume 2. Technical Details

    DTIC Science & Technology

    1987-07-01

    inches above the lower moldline at the centerline with a 0.75-inch joggle at F.S. 68.50. The proposed SPF configuration consisted of the follow- ing...flanges of the waffle pan, where the upper skin, waffle pan and lower skin joined, were modified to reduce the number of joggles on the lower skin...flanges. All the joggles on the upper skin, waffle pan, and lower skin were elini- nated at F.S. 47.50 and 87.50 for simplicity. This was done subsequent

  16. Towards Full Aircraft Airframe Noise Prediction: Detached Eddy Simulations

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Mineck, Raymond E.

    2014-01-01

    Results from a computational study on the aeroacoustic characteristics of an 18%-scale, semi-span Gulf-stream aircraft model are presented in this paper. NASA's FUN3D unstructured compressible Navier-Stokes solver was used to perform steady and unsteady simulations of the flow field associated with this high-fidelity aircraft model. Solutions were obtained for free-air at a Mach number of 0.2 with the flap deflected at 39 deg, with the main gear off and on (the two baseline configurations). Initially, the study focused on accurately predicting the prominent noise sources at both flap tips for the baseline configuration with deployed flap only. Building upon the experience gained from this initial effort, subsequent work involved the full landing configuration with both flap and main landing gear deployed. For the unsteady computations, we capitalized on the Detached Eddy Simulation capability of FUN3D to capture the complex time-dependent flow features associated with the flap and main gear. To resolve the noise sources over a broad frequency range, the tailored grid was very dense near the flap inboard and outboard tips and the region surrounding the gear. Extensive comparison of the computed steady and unsteady surface pressures with wind tunnel measurements showed good agreement for the global aerodynamic characteristics and the local flow field at the flap inboard tip. However, the computed pressure coefficients indicated that a zone of separated flow that forms in the vicinity of the outboard tip is larger in extent along the flap span and chord than measurements suggest. Computed farfield acoustic characteristics from a FW-H integral approach that used the simulated pressures on the model solid surface were in excellent agreement with corresponding measurements.

  17. Flap Side Edge Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  18. Cooperative airframe/propulsion control for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Schweikhard, W. G.; Berry, D. T.

    1974-01-01

    Interactions between propulsion systems and flight controls have emerged as a major control problem on supersonic cruise aircraft. This paper describes the nature and causes of these interactions and the approaches to predicting and solving the problem. Integration of propulsion and flight control systems appears to be the most promising solution if the interaction effects can be adequately predicted early in the vehicle design. Significant performance, stability, and control improvements may be realized from a cooperative control system.

  19. Fuel/Engine/Airframe Trade-Off Study.

    DTIC Science & Technology

    1980-09-01

    34Effect of ,IP-5 Properties on Hot Gas Corrosion and Flame Radiation," Phillips Petroleum Company Report 3753-64R. 1%4. 50. Butze, H. F., R. C. Ehlers ...mm - 4444 .𔃾 .- 40im 40 13 The tnk fel tmpertureis masure in he N. 3 ain ank ili coprtet n displayed in the cockpit. The flight crew, therefore, has

  20. Fluid flow and heat convection studies for actively cooled airframes

    NASA Astrophysics Data System (ADS)

    Mills, A. F.

    This report details progress made on the jet impingement - liquid crystal - digital imaging experiment. With the design phase complete, the experiment is currently in the construction phase. In order to reach this phase two design related issues were resolved. The first issue was to determine NASP leading edge active cooling design parameters. Meetings were arranged with personnel at SAIC International, Torrance, CA in order to obtain recent publications that characterized expected leading edge heat fluxes as well as other details of NASP operating conditions. The information in these publications was used to estimate minimum and maximum jet Reynolds numbers needed to accomplish the required leading edge cooling, and to determine the parameters of the experiment. The details of this analysis are shown in Appendix A. One of the concerns for the NASP design is that of thermal stress due to large surface temperature gradients. Using a series of circular jets to cool the leading edge will cause a non-uniform temperature distribution and potentially large thermal stresses. Therefore it was decided to explore the feasibility of using a slot jet to cool the leading edge. The literature contains many investigations into circular jet heat transfer but few investigations of slot jet heat transfer. The first experiments will be done on circular jets impinging on a fiat plate and results compared to previously published data to establish the accuracy of the method. Subsequent experiments will be slot jets impinging on full scale models of the NASP leading edge. Table 1 shows the range of parameters to be explored. Next a preliminary design of the experiment was done. Previous papers which used a similar experimental technique were studied and elements of those experiments adapted to the jet impingement study. Trade-off studies were conducted to determine which design was the least expensive, easy to construct, and easy to use. Once the final design was settled, vendors were contacted to verify that equipment could be obtained to meet our specifications. Much of the equipment required to complete the construction of the experiment has been ordered or received.

  1. Design and Construction of a Composite Airframe for UAV Research

    DTIC Science & Technology

    1990-06-01

    sparboxes were covered in 1/ 8th inch thick balsa wood . It was necessary to glue balsa cover plates to the foam. Balsa provided a solid base for the access...structure was assembled using cyanoacrylate glue (Figure 13) . All joints were reinforced with fiberglass cloth and resin. With the primary structure...H. Lin y, cond Reader Prof. E. Roberts Wood , Chairman Department of Aeronautics and Astronautics ii S ABSTRACT A half-scale Unmanned Air Vehicle (UAV

  2. Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

    DTIC Science & Technology

    1982-02-01

    Fairchild Swearingen Corporation Pratt & Whitney Aircraft of Canada Ltd. P.O. Box 894 Box 10 San Antonio, Texas 78284 Longueuil , Quebec J4K 4X9 Mr...Antimisting Fuel Engineering and Development Plan, FAA-ED-18-4. The objective was to study the fuel systems of a representative sample of commercial aircraft

  3. Microburst model requirements for flight simulation: An airframe manufacturer's perspective

    NASA Technical Reports Server (NTRS)

    Schoenman, Richard L.

    1987-01-01

    A brief outline is given of topics for presentation and discussion at the workshop. As manufacturers and certifiers of transport airplanes and associated on-board systems, an interest in the prevention of wind shear related accidents and incidents is inherent. The near term objectives are to provide the customers technical support in the areas of training as well as to research existing and potentially improved on-board systems. In the future, many improved systems should be implemented. This will require certification as well as further educational activity in the use of these new systems. A set of wind models is needed for design work which characterize a wide variety of real microbursts as measured during the JAWS project. The wind models should be limited in both size and complexity to just those features which degrade aircraft performance.

  4. Foam composite structures. [for fire retardant airframe materials

    NASA Technical Reports Server (NTRS)

    Delano, C. B.; Milligan, R. J.

    1976-01-01

    The need to include fire resistant foams into state of the art aircraft interior paneling to increase passenger safety in aircraft fires was studied. Present efforts were directed toward mechanical and fire testing of panels with foam inclusions. Skinned foam filled honeycomb and PBI structural foams were the two constructions investigated with attention being directed toward weight/performance/cost trade-off. All of the new panels demonstrated improved performance in fire and some were lighter weight but not as strong as the presently used paneling. Continued efforts should result in improved paneling for passenger safety. In particular the simple partial filling (fire side) of state-of-the-art honeycomb with fire resistant foams with little sacrifice in weight would result in panels with increased fire resistance. More important may be the retarded rate of toxic gas evolution in the fire due to the protection of the honeycomb by the foam.

  5. Landing Gear Door Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  6. Study to Improve Airframe Turbine Engine Rotor Blade Containment

    DTIC Science & Technology

    1977-07-01

    Fragment, 627 FPS Impact Vslocity 79 3/4 Inch Stresskin Test Panel, futer Surface. 139 4 x 7 x 0.25 In. Fragment, 627 FPS Impact Velocity 80 3/4 Inch...Stainless Steel Test Panel, futer Surface, 184 3 x 5 x 0.25 In. Fragment, 755 FOS Impact Velocity 133 .063 In. Stainless Steel Test Panel, Inner Surface

  7. Parametric Cost Estimation Applied to Composite Helicopter Airframes

    DTIC Science & Technology

    1994-03-01

    labor hours include both composite labor and traditional metal labor. In addition, it includes 65 any direct labor hours associated with scrapped work ... Direct labor hours do not include overhead or quality assurance hours. A. DATA COLLECTION The most worrisome and time consuming process of this entire

  8. Fluid flow and heat convection studies for actively cooled airframes

    NASA Technical Reports Server (NTRS)

    Mills, A. F.

    1993-01-01

    This report details progress made on the jet impingement - liquid crystal - digital imaging experiment. With the design phase complete, the experiment is currently in the construction phase. In order to reach this phase two design related issues were resolved. The first issue was to determine NASP leading edge active cooling design parameters. Meetings were arranged with personnel at SAIC International, Torrance, CA in order to obtain recent publications that characterized expected leading edge heat fluxes as well as other details of NASP operating conditions. The information in these publications was used to estimate minimum and maximum jet Reynolds numbers needed to accomplish the required leading edge cooling, and to determine the parameters of the experiment. The details of this analysis are shown in Appendix A. One of the concerns for the NASP design is that of thermal stress due to large surface temperature gradients. Using a series of circular jets to cool the leading edge will cause a non-uniform temperature distribution and potentially large thermal stresses. Therefore it was decided to explore the feasibility of using a slot jet to cool the leading edge. The literature contains many investigations into circular jet heat transfer but few investigations of slot jet heat transfer. The first experiments will be done on circular jets impinging on a fiat plate and results compared to previously published data to establish the accuracy of the method. Subsequent experiments will be slot jets impinging on full scale models of the NASP leading edge. Table 1 shows the range of parameters to be explored. Next a preliminary design of the experiment was done. Previous papers which used a similar experimental technique were studied and elements of those experiments adapted to the jet impingement study. Trade-off studies were conducted to determine which design was the least expensive, easy to construct, and easy to use. Once the final design was settled, vendors were contacted to verify that equipment could be obtained to meet our specifications. Much of the equipment required to complete the construction of the experiment has been ordered or received. The material status list is shown in Appendix B.

  9. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., service, and repair heating, cooling, air conditioning, pressurization systems, and air cycle machines. (1) 34. Inspect, check, troubleshoot, service, and repair heating, cooling, air-conditioning, and... systems and both mechanical and electrical heading, speed, altitude, temperature, pressure, and...

  10. Propulsion/ASME Rocket-Based Combined Cycle Activities in the Advanced Space Transportation Program Office

    NASA Technical Reports Server (NTRS)

    Hueter, Uwe; Turner, James

    1998-01-01

    NASA's Office Of Aeronautics and Space Transportation Technology (OASTT) has establish three major coals. "The Three Pillars for Success". The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center in Huntsville,Ala. focuses on future space transportation technologies under the "Access to Space" pillar. The Advanced Reusable Technologies (ART) Project, part of ASTP, focuses on the reusable technologies beyond those being pursued by X-33. The main activity over the past two and a half years has been on advancing the rocket-based combined cycle (RBCC) technologies. In June of last year, activities for reusable launch vehicle (RLV) airframe and propulsion technologies were initiated. These activities focus primarily on those technologies that support the year 2000 decision to determine the path this country will take for Space Shuttle and RLV. In February of this year, additional technology efforts in the reusable technologies were awarded. The RBCC effort that was completed early this year was the initial step leading to flight demonstrations of the technology for space launch vehicle propulsion. Aerojet, Boeing-Rocketdyne and Pratt & Whitney were selected for a two-year period to design, build and ground test their RBCC engine concepts. In addition, ASTROX, Pennsylvania State University (PSU) and University of Alabama in Huntsville also conducted supporting activities. The activity included ground testing of components (e.g., injectors, thrusters, ejectors and inlets) and integrated flowpaths. An area that has caused a large amount of difficulty in the testing efforts is the means of initiating the rocket combustion process. All three of the prime contractors above were using silane (SiH4) for ignition of the thrusters. This follows from the successful use of silane in the NASP program for scramjet ignition. However, difficulties were immediately encountered when silane (an 80/20 mixture of hydrogen/silane) was used for rocket

  11. Human Reliability Program Overview

    SciTech Connect

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  12. Ostomy Home Skills Program

    MedlinePlus Videos and Cool Tools

    ... Quality Improvement Program About Standards Apply Participant Use Data File (PUF) Resources & FAQs Find a MBSAQIP Center ... Programs About Trauma Programs BleedingControl.org National Trauma Data Bank Trauma Quality Improvement Program Mentoring for Excellence ...

  13. Vehicle Technologies Program Overview

    SciTech Connect

    none,

    2006-09-05

    Overview of the Vehicle Technologies Program including external assessment and market view; internal assessment, program history and progress; program justification and federal role; program vision, mission, approach, strategic goals, outputs, and outcomes; and performance goals.

  14. NIH Minority Programs.

    ERIC Educational Resources Information Center

    National Institutes of Health (DHHS), Bethesda, MD.

    This publication contains brief descriptions of National Institutes of Health programs for underrepresented minorities, including fellowships, programs for high school students, graduate research assistantships, postdoctoral training, and programs for college students. The publication provides a description of each program, eligibility…

  15. NASA's educational programs

    NASA Technical Reports Server (NTRS)

    Brown, Robert W.

    1990-01-01

    The educational programs of NASA's Educational Affairs Division are examined. The problem of declining numbers of science and engineering students is reviewed. The various NASA educational programs are described, including programs at the elementary and secondary school levels, teacher education programs, and undergraduate, graduate, and university faculty programs. The coordination of aerospace education activities and future plans for increasing NASA educational programs are considered.

  16. Nacelle-wing integration

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina

    1992-01-01

    The Aerodynamics Division at NASA ARC is participating in the propulsion airframe integration phase of the High Speed Research Program. The two areas of research being pursued include an experimental program and analysis using computational fluid dynamics. The applied Aerodynamics Branch is conducting the experimental program, which will involve a nacelle airframe model that was tested in the Ames 11- by 11-Foot Transonic Wind Tunnel in 1973. This branch will also assess various Euler codes in predicting nacelle airframe interference effects. The goal is to provide the industry with the necessary data and tools to design a high speed civil transport with favorable propulsion airframe interference.

  17. Naval Postgraduate School Aircraft Synthesis Program (User’s Manual)

    DTIC Science & Technology

    1991-09-01

    207 APPENDIX A ............................................ 208 vii REFERENCES ...................... 291 IN IIL DISTRIUTION LIST...Altitude at Start of Phase 12 240 15 TABLE 2. (cont) Trajectory Variables Variable Global "aribleNumber Cruise Mach Number 183 Cruise Range (nm) 351 ...PERCENT AIRFRAME STRUCTURE 12921. 5861. 27.42 WING 5212. 2364. 11.06 FUSELAGE 4454. 2020. 9.45 HORIZONTAL TAIL 457. 207 . 0.97 VERTICAL TAIL 436. 198. 0.93

  18. NUL Youth Programs

    ERIC Educational Resources Information Center

    Cooper, Maudine Rice

    1977-01-01

    This article indicates some of the ways in which the National Urban League has dealt with the problem of minority youth. These ways include programs such as the Street Academy Program, student internship programs, and the Black Executive Exchange Program, a conference on youth employment, and affiliation with other programs. (Author/AM)

  19. Lippincott Basic Reading Program.

    ERIC Educational Resources Information Center

    Monterey Peninsula Unified School District, Monterey, CA.

    This program, included in "Effective Reading Programs...," serves 459 students in grades 1-3 at 15 elementary schools. The program employs a diagnostic-prescriptive approach to instruction in a nongraded setting through the use of the Lippincott Basic Reading program. When a child enters the program, he is introduced to a decoding…

  20. Acid Rain Program CEM audit program

    SciTech Connect

    Nguyen, K.O.T.; Alexander, T.H.; Dupree, J.C.

    1997-12-31

    This presentation will give an overview of the Acid Rain Program CEM Audit Program: electronic and field audits. The presentation will include the reasons for audits, field audit types and levels the steps used in develop in the audit program and the audit procedures.

  1. TEN MASTER TEACHER AND PROGRAM AWARD PROGRAMS.

    ERIC Educational Resources Information Center

    KOVACH, EDITH M.A.

    IN 1966 THE AMERICAN CLASSICAL LEAGUE HONORED THREE TEACHERS WITH ITS MASTER SECONDARY SCHOOL LATIN TEACHER AND PROGRAM AWARD. AMONG THE 32 PROGRAMS CITED FOR RECOGNITION, TEN (INCLUDING THOSE OF THE AWARD WINNERS) POSSESS CLEARLY INNOVATIVE FEATURES. IN BRIEF THEY FEATURE (1) A FIFTH YEAR ADVANCED PLACEMENT PROGRAM, LATIN AS INTRODUCTORY TO…

  2. Music Program of Study: Educational Program Definition.

    ERIC Educational Resources Information Center

    West Virginia State Dept. of Education, Charleston.

    The West Virginia music study program is a public school K-12 curriculum sequence. This program is divided into the four principal areas of: (1) general classroom music; (2) string instrumental music; (3) wind and percussion instrumental music; and (4) choral music. The general classroom music program is an early and middle childhood sequence of…

  3. Overview of the DoD's rf multifunction structural aperture (MUSTRAP) program

    NASA Astrophysics Data System (ADS)

    Alt, Kevin H.; Lockyer, Allen J.; Coughlin, Daniel P.; Kudva, Jayanth N.; Tuss, James

    2001-08-01

    The proliferation of antenna systems of state-of-the-art military aircraft has challenged major airframe manufacturers to provide additional outer surface platform space for antenna placement while still maintaining a flightworthy structure. The solution is to design antennas that can sustain severe structural load. The recently completed 'RF Multifunction Structural Aperture (MUSTRAP),' contract number F33615-97-2- 3807 performed by Northrop Grumman Corporation (NGC), El Segundo, California and TRW/ASD, Rancho Bernardo, San Diego, California, together with their DoD customer have met this challenge by conceiving the novel technology of Conformal Load-bearing Antenna Structures (CLAS). Under the Air Force Research Laboratory, Air Vehicles Directorate, Structures Division's leadership and direction, the MUSTRAP team have developed multifunction, broadband, structurally integrated, low cost antennas for communications, navigation, identification (CNI) and electronic warfare (EW) applications in the 0.03 to 2.0 GHz range. Two concepts, a fuselage and a vertical tail installation, were designed, analyzed, fabricated, and tested. The fuselage demonstration article was a load bearing multifunction (UHF/SATCOM) antenna 35 by 37 inch panel subjected to combined axial and shear loading, which replicated realistic flight conditions. Ultimate failure loads imposed on the panel were 1,800 pounds per inch axial loading and 600 pounds per inch shearing loading, after successfully withstanding a single lifetime (6,000 hours) of fatigue. Electrical performance was validated using anechoic chamber measurements. The vertical tail concept was a structural excitation multifunction (VHF/UHF) antenna element that can be tailored to fit in virtually any end cap vertical tail configuration. Designed to endure the severe acoustic environment associated with empennage noise sources, the end cap was successfully flight tested on NASA/Dryden's Systems Research Aircraft (SRA) to validate the

  4. Development program to certify composite doubler repair technique for commercial aircraft

    SciTech Connect

    Roach, D.P.

    1997-07-01

    Commercial airframes exceeding 20 service years often develop crack and corrosion flaws. Bonded composite doublers offer a cost effective method to safely extend aircraft lives. The Federal Aircraft Authority (FAA) has completed a project to introduce composite doubler repair technology to the commercial aircraft industry. Instead of riveting steel or aluminum plates for repair, a single composite doubler may be bonded to the damaged structure. Adhesive bonding eliminates stress concentrations caused by fastener holes. Composites are readily formed into complex shapes for repairing irregular components. Also, composite doublers can be tailored to meet specific anisotropy needs, eliminating structural stiffening in directions other than those required. Other advantages include corrosion resistance, a high strength-to-weight ratio, and potential time savings in installation. One phase of this study developed general methodologies and test programs to ensure proper performance of the technique. A second phase focused on reinforcement of an L-1011 door frame, and encompassed all lifetime tasks such as design, analysis, installation, and nondestructive inspection. This paper overviews the project and details the activities conducted to gain FAA approval for composite doubler use. Structural tests evaluated the damage tolerance and fatigue performance of composite doublers while finite element models were generated to study doubler design issues. Nondestructive inspection procedures were developed and validated using full-scale test articles. Installation dry-runs demonstrated the viability of applying composite doublers in hangar environments. The project`s documentation package was used to support installation of a Boron-Epoxy composite repair on a Delta Air Lines L-1011 aircraft. A second product of the results is a Lockheed Service Bulletin which allows the door corner composite doubler to be installed on all L-1011 aircraft. 9 refs., 10 figs., 2 tabs.

  5. NASA geodynamics program: Bibliography

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Seventh Geodynamics Program report summarizes program activities and achievements during 1988 and 1989. Included is a 115 page bibliography of the publications associated with the NASA Geodynamics Program since its initiation in 1979.

  6. General Medical Surveillance Program

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Background on the General Medical Surveillance Program at LeRC is presented. The purpose of the General Medical Surveillance Program at LeRC is outlined, and the specifics of the program are discussed.

  7. Vehicle Technologies Program Implementation

    SciTech Connect

    none,

    2009-06-19

    The Vehicle Technologies Program takes a systematic approach to Program implementation. Elements of this approach include the evaluation of new technologies, competitive selection of projects and partners, review of Program and project improvement, project tracking, and portfolio management and adjustment.

  8. Immersive Visual Programming System

    DTIC Science & Technology

    1995-03-16

    improved virtual programming system. 20 It is another object to provide a virtual programming system that optimally increases a user’s comprehensibility...of program structures. NAVY CASE NO. 75554 It is still another object to provide a virtual programming system that is useful for defining the high...level flow control and data pathways within a program. It is yet another object to provide a virtual programming system that allows for dynamic

  9. LANL Meteorology Program

    SciTech Connect

    Dewart, Jean Marie

    2015-02-09

    The goal of the Meteorology Program is to provide all routine meteorology measurements for LANL operational requirements. This report discusses the program, its routine operations, and other services.

  10. NEMAR plotting computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1981-01-01

    A FORTRAN coded computer program which generates CalComp plots of trajectory parameters is examined. The trajectory parameters are calculated and placed on a data file by the Near Earth Mission Analysis Routine computer program. The plot program accesses the data file and generates the plots as defined by inputs to the plot program. Program theory, user instructions, output definitions, subroutine descriptions and detailed FORTRAN coding information are included. Although this plot program utilizes a random access data file, a data file of the same type and formatted in 102 numbers per record could be generated by any computer program and used by this plot program.

  11. About the Clusters Program

    EPA Pesticide Factsheets

    The Environmental Technology Innovation Clusters Program advises cluster organizations, encourages collaboration between clusters, tracks U.S. environmental technology clusters, and connects EPA programs to cluster needs.

  12. Insights on Aircraft Programmed Depot Maintenance: An Analysis of F-15 PDM

    DTIC Science & Technology

    2008-01-01

    Loredo (2006), RAND has conducted numerous studies that touch on related issues. Cook and Graser (2001) studied the effects of lean manufacturing on...www.rand.org/pubs/monographs/MG372/ Cook, Cynthia R., and John C. Graser, Military Airframe Acquisition Costs: The Effects of Lean Manufacturing , Santa

  13. The Outdoor Programming Handbook.

    ERIC Educational Resources Information Center

    Watters, Ron

    This manual provides guidelines for developing outdoor recreation programs. The manual was prepared for adult outdoor recreation programs, but could be useful for other age groups as well. The following topics are discussed: (1) the historical perspectives of outdoor recreation programming; (2) outdoor programming models, including the club model,…

  14. NASA Microgravity Research Program

    NASA Technical Reports Server (NTRS)

    Woodard, Dan

    1999-01-01

    The Fiscal Year 1998 Annual Report describes key elements of the NASA Microgravity Research Program. The Program's goals, approach taken to achieve those goals, and program resources are summarized. A review of the Program's status at the end of FY1998 and highlights of the ground- and-flight-based research are provided.

  15. OJJDP Tribal Youth Program.

    ERIC Educational Resources Information Center

    Andrews, Chyrl; McKinney, Kay

    2000-01-01

    The Tribal Youth Program, administered by the Department of Justice, awards 3-year grants supporting tribal efforts to prevent and control juvenile crime and to improve reservation juvenile justice systems. Programs include mental health programs, research and evaluation, educational programs addressing communication skills and juvenile crime,…

  16. Migrant Programs in Texas.

    ERIC Educational Resources Information Center

    Carrasco, Frank, Ed.

    The purpose of this handbook is to provide information on migrant programs and services in the state of Texas. Data are gathered from 92 of the 254 counties in Texas. There is a profile for each county selected and for all migrant programs identified in each county. Descriptions of Title III-B migrant programs, the High School Equivalency program,…

  17. Derivation of sorting programs

    NASA Technical Reports Server (NTRS)

    Varghese, Joseph; Loganantharaj, Rasiah

    1990-01-01

    Program synthesis for critical applications has become a viable alternative to program verification. Nested resolution and its extension are used to synthesize a set of sorting programs from their first order logic specifications. A set of sorting programs, such as, naive sort, merge sort, and insertion sort, were successfully synthesized starting from the same set of specifications.

  18. Managing Mentoring Programs.

    ERIC Educational Resources Information Center

    IUME Briefs, 1992

    1992-01-01

    Some programs for helping at-risk youth achieve excellent results, while others do not. One reason for program success can be proper management. Mentoring is a promising strategy for helping at-risk youth. Planners who want to create effective mentoring programs should look at the implementation experiences of other youth programs. Evaluations…

  19. Social Program Implementation.

    ERIC Educational Resources Information Center

    Williams, Walter, Ed.; Elmore, Richard F., Ed.

    This book seeks to stimulate inquiry into the area of implementation in three social policy areas: education programs; community-oriented programs; and transfer-payment*programs. It is intended for government groups and social science researchers, including analysts, who carry out programs, researchers who are engaged in social policy studies, and…

  20. The Cybernetic Writing Program.

    ERIC Educational Resources Information Center

    Lowe, Kelly Fisher

    This paper looks at the role of a Writing Program Administrator, and applies the idea of a cybernetic system to the administration of the program. In this cybernetic model, the Writing Program Administrator (WPA) works as both a problem solver and problem causer, with the responsibility of keeping the program in proper balance. A cybernetic…

  1. Laser Programs Highlights 1998

    SciTech Connect

    Lowdermilk, H.; Cassady, C.

    1999-12-01

    This report covers the following topics: Commentary; Laser Programs; Inertial Confinement Fusion/National Ignition Facility (ICF/NIF); Atomic Vapor Laser Isotope Separation (AVLIS); Laser Science and Technology (LS&T); Information Science and Technology Program (IS&T); Strategic Materials Applications Program (SMAP); Medical Technology Program (MTP) and Awards.

  2. Student Assistance Program.

    ERIC Educational Resources Information Center

    Faulkner, Robin; And Others

    The Student Assistance Program (SAP) is a chemical use prevention and early intervention program. Entering the fifth year of implementation, the SAP has expanded from a part-time service contracted with Mental Health to a school-based program serving two high schools and three middle schools. The program is broad based, employing a variety of…

  3. Viking Lander reliability program

    NASA Technical Reports Server (NTRS)

    Pilny, M. J.

    1978-01-01

    The Viking Lander reliability program is reviewed with attention given to the development of the reliability program requirements, reliability program management, documents evaluation, failure modes evaluation, production variation control, failure reporting and correction, and the parts program. Lander hardware failures which have occurred during the mission are listed.

  4. [PIC Program Evaluation Forms.

    ERIC Educational Resources Information Center

    Short, N. J.

    These 4 questionnaires are designed to elicit teacher and parent evaluations of the Prescriptive Instruction Center (PIC) program. Included are Teacher Evaluation of Program Effectiveness (14 items), M & M Evaluation of Program Implementation (methods and materials specialists; 11 items), Teacher Evaluation of Program Effectiveness--Case Study…

  5. Program analysis for documentation

    NASA Technical Reports Server (NTRS)

    Lolmaugh, G. H.

    1970-01-01

    A program analysis for documentation (PAD) written in FORTRAN has three steps: listing the variables, describing the structure and writing the program specifications. Technical notes on editing criteria for reviewing program documentation, technical notes for PAD, and FORTRAN program analyzer for documentation are appended.

  6. NASA's Microgravity Research Program

    NASA Technical Reports Server (NTRS)

    Woodard, Dan R. (Editor); Henderson, Robin N. (Technical Monitor)

    2000-01-01

    The Fiscal Year 1999 Annual Report describes key elements of the NASA Microgravity Research Program. The Program's goals, approach taken to achieve those goals, and program resources are summarized. A review of the Program's status at the end of FY1999 and highlights of the ground-and-flight research are provided.

  7. Program (systems) engineering

    NASA Technical Reports Server (NTRS)

    Baroff, Lynn E.; Easter, Robert W.; Pomphrey, Richard B.

    2004-01-01

    Program Systems Engineering applies the principles of Systems Engineering at the program level. Space programs are composed of interrelated elements which can include collections of projects, advanced technologies, information systems, etc. Some program elements are outside traditional engineering's physical systems, such as education and public outreach, public relations, resource flow, and interactions within the political environments.

  8. Leadership Development Programs.

    ERIC Educational Resources Information Center

    Kim, Karen A.

    2003-01-01

    Provides a brief sample of degree and non-degree programs currently offered to administrators, staff and faculty in community college leadership. Includes listings on: (1) programs sponsored by national organizations and associations; (2) regional workshops and seminars; (3) community college programs; (4) continuing education programs by…

  9. Light water reactor program

    SciTech Connect

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  10. Programming: Nuts and Bolts.

    ERIC Educational Resources Information Center

    Hartwig, M. Celine

    2000-01-01

    Discusses program implementation as a task-oriented process. Highlights details to consider for effective program delivery and offers suggestions for dealing with unexpected circumstances that may arise throughout the course of a program. Includes a program implementation checklist to be used as a practical planning tool when thinking through the…

  11. C++ Programming Language

    NASA Technical Reports Server (NTRS)

    Shaykhian, Gholam Ali

    2007-01-01

    C++ Programming Language: The C++ seminar covers the fundamentals of C++ programming language. The C++ fundamentals are grouped into three parts where each part includes both concept and programming examples aimed at for hands-on practice. The first part covers the functional aspect of C++ programming language with emphasis on function parameters and efficient memory utilization. The second part covers the essential framework of C++ programming language, the object-oriented aspects. Information necessary to evaluate various features of object-oriented programming; including encapsulation, polymorphism and inheritance will be discussed. The last part of the seminar covers template and generic programming. Examples include both user defined and standard templates.

  12. Technology Commercialization Program 1991

    SciTech Connect

    Not Available

    1991-11-01

    This reference compilation describes the Technology Commercialization Program of the Department of Energy, Defense Programs. The compilation consists of two sections. Section 1, Plans and Procedures, describes the plans and procedures of the Defense Programs Technology Commercialization Program. The second section, Legislation and Policy, identifies legislation and policy related to the Program. The procedures for implementing statutory and regulatory requirements are evolving with time. This document will be periodically updated to reflect changes and new material.

  13. Coastal Inlets Research Program

    DTIC Science & Technology

    2015-02-09

    FEB 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Coastal Inlets Research Program 5a. CONTRACT NUMBER...S) AND ADDRESS(ES) U.S. Army Engineer Research and Development Center,CIRP - The Coastal Inlets Research Program,3909 Halls Ferry Road,Vicksburg,MS...CIRP.aspx Coastal Inlets Research Program The Coastal Inlets Research Program (CIRP) is a R&D Program funded through the Operations & Maintenance

  14. Program Evaluation: The Key to Quality Programming.

    ERIC Educational Resources Information Center

    Johnson, Lawrence J.

    Part of a volume which explores current issues in service delivery to infants and toddlers (ages birth to 3) with handicapping conditions, this chapter presents program evaluation as a comprehensive process comprising three phases: input, process, and output. Three program evaluation models are summarized: Tyler's objective model, Scriven's…

  15. Traditional Planetarium Programming versus Participatory Planetarium Programming.

    ERIC Educational Resources Information Center

    Fletcher, Jack K.

    1980-01-01

    The results of this study indicate that, for the astronomical concepts used, no significant difference in the cognitive domain will occur between the achievement of students who experience a participatory planetarium program and students who experience a traditional lecture-demonstration program. (Author/MK)

  16. Two Feathers Endowment Scholarship Program: Program Evaluation

    ERIC Educational Resources Information Center

    Pierce, Alexandra

    2004-01-01

    The Saint Paul Foundation contracted with the Wilder Research Center to conduct an evaluation of their Two Feathers Scholarship Program. The Two Feathers Scholarship Program is funded through the Two Feathers Endowment, which is one part of the Foundation's SpectrumTrust. SpectrumTrust is a unique partnership between communities of color and The…

  17. Parent Volunteer Programs/Reading Programs.

    ERIC Educational Resources Information Center

    Huyer, Diane

    Designed to be an example of how elementary and secondary schools can involve parents in their children's education, this guide is a compilation of letters to parents, memos, newsletters, and general information concerning Parkway (Missouri) School District's Parent Volunteer program, focusing primarily on the reading program. The first of the…

  18. Programming Models in HPC

    SciTech Connect

    Shipman, Galen M.

    2016-06-13

    These are the slides for a presentation on programming models in HPC, at the Los Alamos National Laboratory's Parallel Computing Summer School. The following topics are covered: Flynn's Taxonomy of computer architectures; single instruction single data; single instruction multiple data; multiple instruction multiple data; address space organization; definition of Trinity (Intel Xeon-Phi is a MIMD architecture); single program multiple data; multiple program multiple data; ExMatEx workflow overview; definition of a programming model, programming languages, runtime systems; programming model and environments; MPI (Message Passing Interface); OpenMP; Kokkos (Performance Portable Thread-Parallel Programming Model); Kokkos abstractions, patterns, policies, and spaces; RAJA, a systematic approach to node-level portability and tuning; overview of the Legion Programming Model; mapping tasks and data to hardware resources; interoperability: supporting task-level models; Legion S3D execution and performance details; workflow, integration of external resources into the programming model.

  19. Analyzing Array Manipulating Programs by Program Transformation

    NASA Technical Reports Server (NTRS)

    Cornish, J. Robert M.; Gange, Graeme; Navas, Jorge A.; Schachte, Peter; Sondergaard, Harald; Stuckey, Peter J.

    2014-01-01

    We explore a transformational approach to the problem of verifying simple array-manipulating programs. Traditionally, verification of such programs requires intricate analysis machinery to reason with universally quantified statements about symbolic array segments, such as "every data item stored in the segment A[i] to A[j] is equal to the corresponding item stored in the segment B[i] to B[j]." We define a simple abstract machine which allows for set-valued variables and we show how to translate programs with array operations to array-free code for this machine. For the purpose of program analysis, the translated program remains faithful to the semantics of array manipulation. Based on our implementation in LLVM, we evaluate the approach with respect to its ability to extract useful invariants and the cost in terms of code size.

  20. The CHROME Honors Program

    NASA Technical Reports Server (NTRS)

    Wilson, Eleanor

    2002-01-01

    The CHROME Honors Program was designed as a two-week residential program for 9th and 1Oth grade students participating in CHROME clubs. The curriculum focused on the health sciences with instruction from: (1) the science and health curriculum of the Dozoretz National Program for Minorities in Applied Sciences (DNIMAS) Program of Norfolk State University (NSU); (2) the humanities curriculum of the NSU Honors Program; (3) NASA-related curriculum in human physiology. An Advisory Committee was formed to work with the Project Coordinator in the design of the summer program.

  1. STI Program Multimedia Initiative

    NASA Technical Reports Server (NTRS)

    Cotter, Gladys A.; Kaye, Karen

    1993-01-01

    This paper relates the experience of the NASA Scientific and Technical Information Program in introducing multimedia within the STI Program framework. A discussion of multimedia technology is included to provide context for the STI Program effort. The STI Program's Multimedia Initiative is discussed in detail. Parallels and differences between multimedia and traditional information systems project development are highlighted. Challenges faced by the program in initiating its multimedia project are summarized along with lessons learned. The paper concludes with a synopsis of the benefits the program hopes to provide its users through the introduction of multimedia illustrated by examples of successful multimedia projects.

  2. Environmental representative program

    SciTech Connect

    McLeod, B.P.

    1984-05-01

    As new pollution regulations are created and existing regulations are made more complex, it is becoming more important for plant personnel to have a knowlege of the environment. The Environmental Representative Program is designed to train plant personnel and is aimed at preventing fines, citations, and negative publicity. The goal of the program is on-going daily compliance assurance, and is divided into two segments: 1) program initiation (general considerations, representative selection, and authorization by management); and 2) program implementation (requirements training, responsibilities development, incorporation into annual goals, and program maintenance). A discussion of how each part of the program is accomplished is presented.

  3. Building Technologies Program Multi-Year Program Plan Program Portfolio Management 2008

    SciTech Connect

    None, None

    2008-01-01

    Building Technologies Program Multi-Year Program Plan 2008 for program portfolio management, including the program portfolio management process, program analysis, performance assessment, stakeholder interactions, and cross-cutting issues.

  4. Modeling EERE deployment programs

    SciTech Connect

    Cort, K. A.; Hostick, D. J.; Belzer, D. B.; Livingston, O. V.

    2007-11-01

    The purpose of the project was to identify and characterize the modeling of deployment programs within the EERE Technology Development (TD) programs, address possible improvements to the modeling process, and note gaps in knowledge for future research.

  5. Superfund Contract Laboratory Program

    EPA Pesticide Factsheets

    The Contract Laboratory Program (CLP) is a national network of EPA personnel, commercial laboratories, and support contractors whose primary mission is to provide data of known and documented quality to the Superfund program.

  6. Sandia's Biofuels Program

    ScienceCinema

    Simmons, Blake; Singh, Seema; Lane, Todd; Reichardt, Tom; Davis, Ryan

    2016-07-12

    Sandia's biofuels program is focused on developing next-generation, renewable fuel solutions derived from biomass. In this video, various Sandia researchers discuss the program and the tools they employ to tackle the technical challenges they face.

  7. Early Retirement Programs.

    ERIC Educational Resources Information Center

    Everett, Peter W.

    1984-01-01

    Early retirement programs offer individuals an alternative to the work ethic while allowing them to maintain job security. Examples are given of several early, partial, and phased retirement programs currently being used in universities and public school systems. (DF)

  8. An A+ Certification Program.

    ERIC Educational Resources Information Center

    Rubenstein, Charles

    2003-01-01

    Describes the computer technology program at Thomas A. Edison Vocational and Technical High School in Queens, New York, all of whose graduates go on to specialty secondary schools for additional certification or to postsecondary education programs. (JOW)

  9. Space Radiation Program Element

    NASA Technical Reports Server (NTRS)

    Krenek, Sam

    2008-01-01

    This poster presentation shows the various elements of the Space Radiation Program. It reviews the program requirements: develop and validate standards, quantify space radiation human health risks, mitigate risks through countermeasures and technologies, and treat and monitor unmitigated risks.

  10. Monte Carlo Example Programs

    SciTech Connect

    Kalos, M.

    2006-05-09

    The Monte Carlo example programs VARHATOM and DMCATOM are two small, simple FORTRAN programs that illustrate the use of the Monte Carlo Mathematical technique for calculating the ground state energy of the hydrogen atom.

  11. NASA Geodynamics Program

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Activities and achievements for the period of May 1983 to May 1984 for the NASA geodynamics program are summarized. Abstracts of papers presented at the Conference are inlcuded. Current publications associated with the NASA Geodynamics Program are listed.

  12. Automated preventive maintenance program

    NASA Technical Reports Server (NTRS)

    Cea, E. J.; Grieger, T. H.

    1971-01-01

    Maintenance program which is concise and inexpensive to operate adapts to almost any system that has a FORTRAN compiler. Program operates on a stored data base with an output consisting of scheduling information and various management reports.

  13. Parallel programming with PCN

    SciTech Connect

    Foster, I.; Tuecke, S.

    1991-12-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and C that allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. In includes both tutorial and reference material. It also presents the basic concepts that underly PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous FTP from Argonne National Laboratory in the directory pub/pcn at info.mcs.anl.gov (c.f. Appendix A).

  14. Parallel programming with PCN

    SciTech Connect

    Foster, I.; Tuecke, S.

    1991-09-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, a set of tools for developing and debugging programs in this language, and interfaces to Fortran and C that allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. It includes both tutorial and reference material. It also presents the basic concepts that underlie PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous FTP from Argonne National Laboratory at info.mcs.anl.gov.

  15. Sandia's Biofuels Program

    SciTech Connect

    Simmons, Blake; Singh, Seema; Lane, Todd; Reichardt, Tom; Davis, Ryan

    2014-07-22

    Sandia's biofuels program is focused on developing next-generation, renewable fuel solutions derived from biomass. In this video, various Sandia researchers discuss the program and the tools they employ to tackle the technical challenges they face.

  16. High Speed Research Program

    NASA Technical Reports Server (NTRS)

    Anderson, Robert E.; Corsiglia, Victor R.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    An overview of the NASA High Speed Research Program will be presented from a NASA Headquarters perspective. The presentation will include the objectives of the program and an outline of major programmatic issues.

  17. Nonflammable Clothing Development Program

    NASA Technical Reports Server (NTRS)

    Johnston, Richard; Radnofsky, Matthew I.

    1968-01-01

    Protective clothing is of major importance in our space program. The authors discuss the requirements, selection, and testing of materials considered for use in the program. The various types of garments worn by astronauts and support personnel are briefly described.

  18. Coalbed Methane Outreach Program

    EPA Pesticide Factsheets

    Coalbed Methane Outreach Program, voluntary program seeking to reduce methane emissions from coal mining activities. CMOP promotes profitable recovery/use of coal mine methane (CMM), addressing barriers to using CMM instead of emitting it to atmosphere.

  19. Mars exploration program

    NASA Technical Reports Server (NTRS)

    Weary, Dwayne

    1993-01-01

    An overview of the Mars Exploration Program is presented in outline and graphic form. Mission objectives, mission strategy, operations concept, transportation element, launch vehicle considerations and program schedule are addressed.

  20. Medical Assisting Program Standards.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This publication contains statewide standards for the medical assisting program in Georgia. The standards are divided into 12 categories; Foundations (philosophy, purpose, goals, program objectives, availability, evaluation); Admissions (admission requirements, provisional admission requirements, recruitment, evaluation and planning); Program…

  1. Python to learn programming

    NASA Astrophysics Data System (ADS)

    Bogdanchikov, A.; Zhaparov, M.; Suliyev, R.

    2013-04-01

    Today we have a lot of programming languages that can realize our needs, but the most important question is how to teach programming to beginner students. In this paper we suggest using Python for this purpose, because it is a programming language that has neatly organized syntax and powerful tools to solve any task. Moreover it is very close to simple math thinking. Python is chosen as a primary programming language for freshmen in most of leading universities. Writing code in python is easy. In this paper we give some examples of program codes written in Java, C++ and Python language, and we make a comparison between them. Firstly, this paper proposes advantages of Python language in relation to C++ and JAVA. Then it shows the results of a comparison of short program codes written in three different languages, followed by a discussion on how students understand programming. Finally experimental results of students' success in programming courses are shown.

  2. Automatic program annotation (AUTONOTE)

    NASA Technical Reports Server (NTRS)

    Neely, M. D.; Tyson, J. W.

    1970-01-01

    A preliminary identification of tools that can be used in the documentation process is described. Some areas of program documentation are identified for automation. The assembly language program is emphasized.

  3. ICASE Computer Science Program

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The Institute for Computer Applications in Science and Engineering computer science program is discussed in outline form. Information is given on such topics as problem decomposition, algorithm development, programming languages, and parallel architectures.

  4. About the RAD Program

    EPA Pesticide Factsheets

    EPA serves as a technical clearinghouse on responsible appliance disposal program development and implementation; calculates annual and cumulative program benefits in terms of ODS and GHG emission savings and equivalents, etc.

  5. Joint Program Management Handbook

    DTIC Science & Technology

    1994-12-01

    the Engieermg and Manufacuring Devopment Phase. Nfilestoae HI- Develommen Annros Devopment approval marks a significant step for any program, but it is...to review concept formulaton. Systems Engilneertn As with service programs, systems engineering in joint program management is an essential tool . I...MANAGEMENT HANDBOOK On=e wd Umawtaiutt As discussed in Chapter 7, systems analysis of relationships is a usef tool for joint program managers. The joint

  6. Aging is not programmed

    PubMed Central

    Blagosklonny, Mikhail V

    2013-01-01

    Aging is not and cannot be programmed. Instead, aging is a continuation of developmental growth, driven by genetic pathways such as mTOR. Ironically, this is often misunderstood as a sort of programmed aging. In contrast, aging is a purposeless quasi-program or, figuratively, a shadow of actual programs. “The brightest flame casts the darkest shadow.” -George Martin PMID:24240128

  7. Software For Integer Programming

    NASA Technical Reports Server (NTRS)

    Fogle, F. R.

    1992-01-01

    Improved Exploratory Search Technique for Pure Integer Linear Programming Problems (IESIP) program optimizes objective function of variables subject to confining functions or constraints, using discrete optimization or integer programming. Enables rapid solution of problems up to 10 variables in size. Integer programming required for accuracy in modeling systems containing small number of components, distribution of goods, scheduling operations on machine tools, and scheduling production in general. Written in Borland's TURBO Pascal.

  8. Aeroacoustics Research Program

    NASA Technical Reports Server (NTRS)

    Myers, Michael K.; Posey, Joe W. (Technical Monitor)

    2005-01-01

    Since its inception in January 2003, the program has provided support for 1 faculty and 1 graduate student researcher. One Graduate Research Scholar Assistant was partially supported by this award. One student has completed his M.S. degree program and 1 has nearly completed the D.Sc. degree program (expected completion Fall 2005). The program has generated 1 D.Sc. dissertation. 1 M.S. theses and 2 publications.

  9. NASA's Technology Utilization Program.

    NASA Technical Reports Server (NTRS)

    Farley, C. F.

    1972-01-01

    NASA's Technology Utilization Program is described, illustrating how it can be useful in achieving improved productivity, providing more jobs, solving public sector challenges, and strengthening the international competitive situation. Underlying the program is the fact that research and development conducted in NASA's aeronautics and space programs have generated much technical information concerning processes, products, or techniques which may be useful to engineers, doctors, or to others. The program is based on acquisition and publication, working with the user, and applications engineering.

  10. Practical Literacy Programming.

    ERIC Educational Resources Information Center

    Primary English Teaching Association, Newtown (Australia).

    Elementary school teachers know that classroom experiences do not just happen, but reflect a teaching and learning program that synthesizes a host of contemporary, and sometimes competing, concerns. To be coherent a program is something of an art form. This book elaborates some programming approaches developed by expert practitioners around…

  11. Program Resource Guide.

    ERIC Educational Resources Information Center

    National School Resource Network, Washington, DC.

    This program resource guide is a compilation of all programs and projects on preventing school violence and vandalism referenced in National School Resource Network (NSRN) materials. The programs cited are described in NSRN trainers' guides, participant guides, technical assistance bulletins, an "Aha" listing, and a compendium. The index is…

  12. Certification Programs for Citrus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus certification programs designed to ensure that healthy plants of the highest genetic potential are being planted in the field are the basic building block of an integrated pest management program. Certification programs began for citrus began with the discovery that the diseases were graft t...

  13. The School Breakfast Program

    ERIC Educational Resources Information Center

    US Department of Agriculture, 2009

    2009-01-01

    The School Breakfast Program is a federally assisted meal program operating in public and nonprofit private schools and residential child care institutions. It began as a pilot project in 1966, and was made permanent in 1975. The School Breakfast Program is administered at the Federal level by the Food and Nutrition Service. At the State level,…

  14. Instructional Program Review.

    ERIC Educational Resources Information Center

    Austin Community Coll., TX.

    This document describes the 1993-94 program review process for Austin Community College (ACC), in Texas. First, the goals of program review are briefly reviewed and ACC's mission and instructional philosophy are set forth. The structure and process is then described, indicating that an Instructional Program Review Committee (PRC), formed of two…

  15. Proposal: Developmental Education Program.

    ERIC Educational Resources Information Center

    Helm, Phoebe

    Three program objectives are articulated for establishing a developmental education program to increase retention and graduation rates among academically disadvantaged students at Triton College: (1) instituting horizontal (teaching basic skills) and vertical (assisting in the transfer of basic skills to students' total educational programs)…

  16. Evaluating Occupational Programs.

    ERIC Educational Resources Information Center

    Long, James P.

    1987-01-01

    Stresses the importance of evaluating occupational programs on a regular basis. Offers a brief explanation of the approaches to program evaluation taken at the Dallas County Community College District (TX), South Puget Sound Community College (WA), and Triton College (IL). Offers a list of references on program evaluation. (CBC)

  17. Surface-Shading Program

    NASA Technical Reports Server (NTRS)

    Plessel, Todd

    1992-01-01

    Surface Shading program, SURF, developed to enable interactive input of grid and solution files from PLOT3D/AMES program; to use those files in interactive creation of wire-frame, shaded, and function-mapped images of parts to view; then to put out ARCGraph standard files animated by use of GAS (COSMIC Program ARC-12379). Written in C.

  18. Waunakee's Summer Science Program.

    ERIC Educational Resources Information Center

    O'Neil, J. Peter

    1981-01-01

    Describes Waunakee Community School's six-week Summer Science Program for students entering the seventh grade. Students are selected for this science enrichment program on the basis of interest, ability, and maturity. Program content includes wetlands, forests, prairies, and animals, concluding with a camping trip. (DS)

  19. Software Development Program.

    ERIC Educational Resources Information Center

    Collin County Community Coll., McKinney, TX.

    The Software Development Program described in this report was developed at Collin County Community College as a pilot associate degree program for the State of Texas. Drawing from an employer needs assessment and a DACUM (Developing a Curriculum) process, the two-year associate in applied science (AAS) program was developed to train scientific…

  20. The Louisiana Scholarship Program

    ERIC Educational Resources Information Center

    Egalite, Anna J.; Mills, Jonathan N.

    2014-01-01

    The Louisiana Scholarship Program (LSP), also known as the Student Scholarships for Educational Excellence Program, provides public funds for low-income students in low-performing public schools to enroll in local private schools. The program was initially piloted in New Orleans in 2008; Louisiana governor Bobby Jindal and the state legislature…

  1. GLOBE Program Teacher's Guide.

    ERIC Educational Resources Information Center

    1997

    The GLOBE Program is a worldwide, hands-on educational program for elementary and secondary school students. GLOBE aims to increase student achievement in mathematics and science, awareness towards the environment, and improve science process skills through network technology. This teacher's guide provides an overview of the GLOBE program and…

  2. Minority Male Afterschool Program.

    ERIC Educational Resources Information Center

    Dalton, Herbert F., Jr.

    Through a program called the Minority Male Afterschool Program (MMAP), college students at Mississippi Valley State University in Itta Bena (Mississippi) are working one-on-one with high school students. The MMAP is an enrichment program that encourages at-risk African American students aged 12 to 19 to complete high school and pursue…

  3. X-33 Program Status

    NASA Technical Reports Server (NTRS)

    Dill, Charlie C.; Austin, Robert E. (Technical Monitor)

    2000-01-01

    The presentation briefly presents the current status of the program. The program's objectives and near term plans are stated. A brief description of the vehicle configuration, the technologies to be demonstrated and the missions to be flown are presented. Finally, a status of the vehicle assembly, the launch control center development and the significant test programs' accomplishments are presented.

  4. TARCOG Home Start Program.

    ERIC Educational Resources Information Center

    Top of Alabama Regional Council of Governments, Huntsville. Human Resources Program.

    This report describes the Top of Alabama Regional Council of Governments (TARCOG) Home Start Program. Five aspects of the program are presented. (1) The nutrition component is aimed at helping parents make the best use of food resources through good planning, buying, and cooking. (2) The health program involves provision of medical and dental…

  5. Modern programming language

    NASA Technical Reports Server (NTRS)

    Feldman, G. H.; Johnson, J. A.

    1980-01-01

    Structural-programming language is especially-tailored for producing assembly language programs for MODCOMP II and IV mini-computes. Modern programming language consists of set of simple and powerful control structures that include sequencing alternative selection, looping, sub-module linking, comment insertion, statement continuation, and compilation termination capabilities.

  6. Customer Service Programming

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Use of computer program STRCMACS has enabled Illinois Bell Telephone, a subsidiary of American Telephone and Telegraph to cut software development costs about 10 percent by reducing program maintenance and by allowing the department to bring other software into operation more quickly. It has also been useful in company training of programming staff.

  7. International Education Programs.

    ERIC Educational Resources Information Center

    Charles, Richard F.

    In response to global changes and a growing focus on international affairs, Foothill and De Anza Colleges have developed a number of international education programs. Since their beginnings, both colleges have hosted full-time students from other countries under the F-1 Visa Program. Another program, Campus Abroad, is a partnership arrangement…

  8. Surgical Technology Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This surgical technology program guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a surgical technology program. The program guide is designed to relate primarily to the development of those skills needed by individuals in the field to provide services in the…

  9. Building Effective Afterschool Programs.

    ERIC Educational Resources Information Center

    Fashola, Olatokunbo S.

    Through a comprehensive review of various afterschool programs across the United States, this resource provides a practical overview of the research and best practices that can be easily adapted and applied in the development of highly effective afterschool programs. chapters focus on: (1) "Why Afterschool Programs?" (benefits, challenges, and…

  10. PROGRAMMED LEARNING PACKET.

    ERIC Educational Resources Information Center

    Modern Language Association of America, New York, NY.

    MATERIALS CONCERNING PROGRAMED INSTRUCTION IN FOREIGN LANGUAGES, PUBLISHED FROM 1960 TO 1967, ARE COLLECTED IN THIS PACKET FOR LANGUAGE TEACHERS AND PERSONS INTERESTED IN THE FUTURE USES OF THE LANGUAGE LABORATORY. INCLUDED ARE--(1) "PROGRAMED LEARNING OF A SECOND LANGUAGE" BY HARLAN LANE, (2) "A PRIMER OF PROGRAMED INSTRUCTION IN FOREIGN LANGUAGE…

  11. Future US scientific program

    SciTech Connect

    Price, L.E.

    1991-01-01

    Central to planning for the future program of high energy physics in the US is the Superconducting Super Collider. While it is being built during roughly the next decade, the present HEP laboratories plan an extensive program of physics measurements. Upgrades and new facilities will allow a vigorous program. 3 figs.

  12. Honors Scholar Program.

    ERIC Educational Resources Information Center

    Lehner, Margaret

    A proposal is presented for an Honors Scholar Program at Moraine Valley Community College in response to the need to provide gifted students with the extra challenges they seek. After providing a rationale for the program, the membership of the steering committee and curriculum committees that would develop and guide the program is designated.…

  13. Employment and Training Programs.

    ERIC Educational Resources Information Center

    Minnesota State Office of the Legislative Auditor, St. Paul. Program Evaluation Div.

    This report examines the effectiveness of employment and training programs in Minnesota and discusses the impact of the 1985 Jobs Bill state legislation. Chapter 1 provides an introduction to Minnesota's programs and to studies of employment and training programs conducted nationwide. Chapter 2 studies the use of Job Training Partnership Act funds…

  14. Children's Programming Guidelines.

    ERIC Educational Resources Information Center

    Cumberland County Public Library and Information Center, Fayetteville, NC.

    Suggestions for establishing children's library programs in the Cumberland County, North Carolina, library system include descriptions of types of audiences, types of programs, and elements of programs. Selection guidelines for topics and materials cover the following areas: (1) art projects; (2) costumes; (3) creative dramatics; (4) drawing; (5)…

  15. The Zero Program

    ERIC Educational Resources Information Center

    Roland, Erling; Midthassel, Unni Vere

    2012-01-01

    Zero is a schoolwide antibullying program developed by the Centre for Behavioural Research at the University of Stavanger, Norway. It is based on three main principles: a zero vision of bullying, collective commitment among all employees at the school using the program, and continuing work. Based on these principles, the program aims to reduce…

  16. Program Fighter - An Evaluation.

    ERIC Educational Resources Information Center

    Hull, David G.; Fowler, Wallace T.

    Described is a computer program for the sizing of subsonic and supersonic fighters which has been adapted for use in an aerospace engineering design course. Following a description of the program, an evaluation of its use in the university is presented. It is concluded that computer programs for the conceptual design of aerospace vehicles can play…

  17. Barbering Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This program guide presents the barbering program for technical institutes in Georgia. The general information section contains the following: purpose and objectives; program description, including admissions, typical job titles, and accreditation and certification; and curriculum model, including standard curriculum sequence and lists of courses.…

  18. Exemplary Program: Sharing Responsibility.

    ERIC Educational Resources Information Center

    McCullough, Stephen

    1990-01-01

    Describes the secondary vocational/special education program at Elk Mound, Wisconsin, that was selected as one of 12 exemplary programs nationwide for use of Carl Perkins funding. The program prepares students with disabilities for the work world through participation in mainstream vocational courses. (Author/JOW)

  19. Maine's Employability Skills Program

    ERIC Educational Resources Information Center

    McMahon, John M.; Wolffe, Karen E.; Wolfe, Judy; Brooker, Carrie

    2013-01-01

    This Practice Report describes the development and implementation of the "Maine Employability Skills Program," a model employment program developed by the Maine Division for the Blind and Visually Impaired (DBVI). The program was designed to support the efforts of the chronically unemployed or underemployed. These consumers were either…

  20. Program Evaluation: Resource Manual.

    ERIC Educational Resources Information Center

    Hayden, David L.

    Intended for administrators and evaluators, the manual identifies models useful in evaluating special education programs in Maryland. An introduction to program evaluation, defines the concept of educational program evaluation, notes its purpose, and addresses its current status in the field of special education. Chapter 2 goes into greater depth…