SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS
A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 16 - AUGUST 12, 2005
05 AIRCRAFT DESIGN, TESTING AND PERFORMANCE - PART I
Includes all stages of design of aircraft and aircraft structures and systems.
Also includes aircraft testing, performance, and evaluation, and aircraft and flight simulation technology.
For related information see also 18 Spacecraft Design, Testing and Performance; and 39 Structural Mechanics.
For land transportation vehicles see 85 Technology Utilization and Surface Transportation.
20050188574 SRI International Corp., Menlo Park, CA USA
Integrating Mission, Robot Localization and Communication Requirements Through Collaboration
Ortiz, Charles L.; May 2005; 8 pp.; In English; Original contains color illustrations Contract(s)/Grant(s): N00014-03-C-0264 Report No.(s): AD-A434157; No Copyright; Avail: Defense Technical Information Center (DTIC)
To develop a de-centralized system for allocating mobile sensor assets controlled by teams of autonomous air vehicle (AVs) and deployed in spatially complex urban environments. The sensor assets are to support AV missions involving the pursuit of one or more mobile intelligent ground adversaries. Since sensor information is typically uncertain and incomplete, AVs must be able to cooperate to coordinate sensor assignments in the most efficient way possible. The environments in which such teams are deployed are spatially complex, introducing additional uncertainty arising from perceptual occlusions and the like. In addition to target tracking, we also plan to develop distributed algorithms for dynamically clustering vehicles around objects of interest (e.g. to protect a convoy). Existing approaches to coordinating the activities of AVs have focused on essentially 2D environments. DTIC
Air Navigation; Cities; Drone Vehicles; Position (Location); Robots
20050188625 Purdue Univ., West Lafayette, IN USA
| |
| Tools for Aviation/Aerospace |
| IHS sells products and services designed to meet the needs of today's engineers. To learn more, and for a free quote, please complete the form below. |
|
Laminar Boundary-Layer Instabilities on Hypersonic Cones: Computations for Benchmark Experiments
Robarge, Tyler W.; Schneider, Steven P.; Jun. 2005; 19 pp.; In English Report No.(s): AD-A434260; AIAA-2005-5024; No Copyright; Avail: CASI; A03, Hardcopy
Although significant advances have been made in hypersonic boundary-layer transition prediction in the last several decades, most design work still relies on empirical correlations or wind tunnel tests. Codes using the semi-empirical eN method will need to be verified and validated before being used for expensive flight vehicles. The STABL code package and its PSE-Chem stability solver are used to compute first and second mode instabilities for both sharp and blunt cones at wind tunnel conditions, with laminar mean flows provided by the DPLR2D Navier-Stokes code. Stetson’s 3.81 mm blunt cone case, a sharp cone at Mach 3.5, and a very blunt cone at Mach 8 are analyzed. The computed transition locations agree well with previous computations by other researchers, but larger differences are seen in the local amplification rates for the Stetson blunt cone case. the applicability of various transport property models and their effect on boundary layer stability are examined. This work helps to extend the applicability of STABL to low-temperature flows. DTIC
Coding; Hypersonic Flight; Hypersonics; Laminar Boundary Layer; Nose Cones; Stability
20050188648 Air Force Inst. of Tech., Wright-Patterson AFB, OH USA
Full Capability Formation Flight Control
Osteroos, Ryan K.; Feb. 2005; 204 pp.; In English; Original contains color illustrations Report No.(s): AD-A434288; AFIT/GAE/ENY/05-M16; No Copyright; Avail: CASI; A10, Hardcopy
The subject of automatic formation flight control is of current interest to the development of Unmanned Aerial Vehicles (UAV). Previous control approaches have been refined in this work to allow more robust maneuvering and to include a fourth control parameter. The equations of motion for each aircraft as a point mass, expressed in a wind-axis coordinate system, are coupled into differential equations that model the two aircraft system dynamics. Control laws are developed that include proportional and integral action. Gains are determined based on formation performance. Lead maneuvers are simulated and the controller is gauged on its ability to maintain the commanded formations in and out of the vortex wake generated by the lead aircraft. A Dryden wind model at varying intensities is applied to the system. In simulation the controller maintained acceptable performance in all maneuvers tested. A slightly modified controller was applied to a USAF NF-16D aircraft for flight testing. Utilizing a data link system and a virtual lead aircraft generated from a ground based control station, the NF-16D was able to flight test the controller. In-flight, the controller was stable, and able to perform all of the desired formation hold and change maneuvers. DTIC
Drone Vehicles; Flight Control
20050188698 Military Academy, West Point, NY USA
A Data Warehouse to Support Condition Based Maintenance (CBM)
Henderson, Steven J.; Kwinn, Michael J., Jr; May 2005; 373 pp.; In English Contract(s)/Grant(s): Proj-DSE-R-0509 Report No.(s): AD-A434357; USMA-DSE-TR-0509; DSE-R-0530; No Copyright; Avail: CASI; A16, Hardcopy
The USA Army’s legacy maintenance strategy for its helicopter fleet is centered on replacing and repairing components based on aircraft hours flown. This strategy overlooks how variations in environmental conditions, component stresses, and other exogenous factors effect the lifetime of specific components across the entire fleet of Army Aviation Aircraft. This report describes the design and implementation of a data warehouse that subsumes many disparate databases currently housing information about these factors. This data warehouse supports a common synchronized ‘maintenance picture’ that includes state, health, usage, and logistics data for any component on any helicopter in the fleet. This view enables researchers and planners to individually manage component maintenance according to a ‘condition based’ policy. This report discusses a systems engineering approach to creating a data warehouse including logical and physical designs, data management strategies, and an implementation plan. Discussion is also included detailing how the warehouse might be adopted for condition-based maintenance of all Army systems. DTIC
Data Bases; Data Management; Maintenance
20050188736 Air Force Inst. of Tech., Wright-Patterson AFB, OH USA
| |
| Aerospace Engineering Design |
| ESDU packages provide validated design data, methods and software, offering a valuable toolset to aerospace engineers. To learn more, and for a free quote, please complete the form below. |
|
Experimentation and Analysis of Composite Scarf Joint
Cook, Benjamin M.; Mar. 2005; 215 pp.; In English; Original contains color illustrations Report No.(s): AD-A434441; AFIT/GA/ENY/05-M03; No Copyright; Avail: Defense Technical Information Center (DTIC)
Composite bonded scarf repairs were examined by experimentally measuring and analytically predicting the residual curing strains and strains due to mechanical loading. To accomplish this a three prong approach was used: a full strain field through a repaired laminate’s thickness was measured for both a loaded specimen and a specimen with the residual strain released, models were developed for comparison to both states, and data was collected for large tensile test specimens at various stages of being scarf repaired. A ^14:1 straight scarfed one-inch wide specimen was used to collect Moire interferometry data to calculate a full strain field due to mechanical loading and strain release. A three-dimensional thermo mechanical linear elastic analysis using an Air Force Research Laboratory in-house stress analysis program B-Spline Analysis Method (BSAM) results were correlated to the Moire interferometry test results. Three large tensile test specimens were tested as manufactured, three were tested with a scarfed hole in the center, and the remaining were tested with a scarf repair centered on a hole in the center. The strain gage results from the panels are presented. An additional feature of this work was to document each of the difficulties present in the given methods incorporated in this research. DTIC
Composite Materials; Interferometry; Residual Stress; Scarf Joints; Stress Analysis
20050188760 Army Research Inst. Field Unit, Fort Rucker, AL USA
Introduction to and Review of Simulator Sickness Research
Johnson, David M.; Apr. 2005; 70 pp.; In English Contract(s)/Grant(s): Proj-A790 Report No.(s): AD-A434495; ARI-RR-1832; No Copyright; Avail: CASI; A04, Hardcopy
This report reviews, and explains the research literature pertaining to simulator sickness. Simulator sickness is a form of motion sickness. Consequently, motion sickness is reviewed also. Special emphasis is given to simulator-based flight training--especially helicopter flight training. This review includes the sensory basis of the perception of motion, the terminology of motion sickness and simulator sickness, a selected history of these research fields, sickness signs and symptoms, measurement issues, incidence of sickness, residual aftereffects, adaptation to a novel motion environment, susceptibility factors, performance issues, training issues, safety issues, treatment, theory, guidelines for simulator-based flight training, and suggestions for further research. The sensory conflict theory and the postural instability theory are described insofar as they relate both to motion sickness and to simulator sickness. The effect of simulator sickness on training effectiveness, if any, remains a subject for future applied research. DTIC
Flight Simulators; Flight Training; Helicopters; Motion Sickness
20050188805 Integrated Smart Structures, Inc., Copley, OH USA
Rapid and Robust Dynamics-Based Nondestructive Method for Aerospace Structural Health Monitoring
Qiao, Pizhong; Lestari, Wahvu; Jun. 2005; 37 pp.; In English Contract(s)/Grant(s): FA9550-04-C-0078 Report No.(s): AD-A434580; ISS00004-F; AFRL-SR-AR-TR-05-0228; No Copyright; Avail: CASI; A03, Hardcopy
Report developed under STTR contract for Topic F045-016-0125 addresses dynamic-based damage identification techniques for structural health monitoring (SHM) of aerospace structures. Two systems (i.e., the scanning laser vibrometer (SLV) and PVDF sensor) are used to acquire the dynamic information, and effective damage detection algorithms (e.g., the gapped smoothing method (GSM) and generalized fractal dimension (GFD) and schemes (e.g., the uniform load surface (ULS) and combined static/dynamic techniques) are developed to evaluate the damage. It is demonstrated that both the GSM and GFD methods are capable of identifying damage without baseline information of healthy structure. Application of the static/dynamic approach improves the performance of the damage identification, and the ULS increases the effectiveness of the detection at low modes. In general, the PVDF sensor system is good for acquiring several low curvature mode shapes; while the SLV system can generate higher displacement modes. Utilizing the advantages of each measurement system, the proposed identification algorithms have great potential for viable SHM products, e.g., the PVDF sensor system for on-board and the SLV system for portable on-site monitoring. The proposed sensor systems and developed identification techniques pave the foundation for further refinement of the dynamics-based method, field implementation and commercial development. DTIC
Damage; Detection; Health
20050188806 Michigan Univ., Ann Arbor, MI USA
Aeroelasticity, Aerothermoelasticity and Aeroelastic Scaling of Hypersonic Vehicles Freidmann, Peretz P.; Powell, Kenneth G.; Dec. 2004; 21 pp.; In English Contract(s)/Grant(s): F49620-01-1-0158 Report No.(s): AD-A434581; AFRL-SR-AR-TR-05-0227; No Copyright; Avail: CASI; A03, Hardcopy
This final report describes the work during the period of the grant. Three separate hypersonic aeroelastic stability problems were considered: (a) a typical cross section having a double wedge airfoil, (b) the stability of a low aspect ratio wing, also with a double wedge airfoil, and (c) the behavior of a complete generic hypersonic vehicle. For problems (a) the unsteady airloads were computed using third order piston theory, as well a CFD based Euler and Navier-Stokes loads. For case (b) piston theory, Euler and Navier-Stokes based airloads were used, and case (c) both piston theory and Euler airloads were used. For the three-dimensional wing the treatment of thermal effect was also considered by solving the heat transfer problem using the Navier Stokes equations to determine the temperature distribution over the vehicle and conducting an aeroelastic analysis that accounts for the effect of thermal stresses and material degradation on the mode shapes. These mode shapes were used in an aeroelastic analysis based on 3rd order piston theory. This comprehensive treatment of the aerothermoelastic problem, the first of its kind in the literature, produces large reductions in aeroelastic stability margins. The results indicate that the flutter boundaries for third order piston theory can differ by 35% from those based on Euler unsteady loads. Solutions based on the loads obtained from the solution of the Navier-Stokes equation indicate further changes in aeroelastic stability margins. Important conclusions for the design of such vehicles are summarized in the body of the report. DTIC
Aeroelasticity; Aerothermoelasticity; Computational Fluid Dynamics; Flutter; Heat Transfer; Hypersonic Vehicles; Hypersonics; Stability; Structural Analysis
20050192472 NASA Langley Research Center, Hampton, VA, USA
Flight Test Evaluation of Situation Awareness Benefits of Integrated Synthetic Vision System Technology f or Commercial Aircraft
Prinzel, Lawrence J., III; Kramer, Lynda J.; Arthur, Jarvis J., III; [2005]; 6 pp.; In English; 2005 (13th) International Symposium on Aviation Psychology, 18-21 Apr. 2005, Oklahoma City, OK, USA Contract(s)/Grant(s): 23-079-60-20; No Copyright; Avail: CASI; A02, Hardcopy
Research was conducted onboard a Gulfstream G-V aircraft to evaluate integrated Synthetic Vision System concepts during flight tests over a 6-week period at the Wallops Flight Facility and Reno/Tahoe International Airport. The NASA Synthetic Vision System incorporates database integrity monitoring, runway incursion prevention alerting, surface maps, enhanced vision sensors, and advanced pathway guidance and synthetic terrain presentation. The paper details the goals and objectives of the flight test with a focus on the situation awareness benefits of integrating synthetic vision system enabling technologies for commercial aircraft. Author
Flight Tests; Systems Integration; Enhanced Vision; Prevention
20050192626 Georgia Inst. of Tech., Atlanta, GA, USA
Noise Reduction Through Circulation Control
Munro, Scott E.; Ahuja, K. K.; Englar, Robert J.; Proceedings of the 2004 NASA/ONR Circulation Control Workshop, Part 1; June 2005, pp. 497-527; In English; 39th AIAA Aerospace Sciences Meeting and Exhibit, 1-8 Jan. 2001, USA; See also 20050192624; Original contains black and white illustrations Contract(s)/Grant(s): NAG1-2146 Report No.(s): AIAA Paper 2001-0666; No Copyright; Avail: CASI; A03, Hardcopy
Circulation control technology uses tangential blowing around a rounded trailing edge or a leading edge to change the force and moment characteristics of an aerodynamic body. This technology has been applied to circular cylinders, wings, helicopter rotors, and even to automobiles for improved aerodynamic performance. Only limited research has been conducted on the acoustic of this technology. Since wing flaps contribute to the environmental noise of an aircraft, an alternate blown high lift system without complex mechanical flaps could prove beneficial in reducing the noise of an approaching aircraft. Thus, in this study, a direct comparison of the acoustic characteristics of high lift systems employing a circulation control wing configuration and a conventional wing flapped configuration has been made. These results indicate that acoustically, a circulation control wing high lift system could be considerably more acceptable than a wing with conventional mechanical flaps. Author
Noise Reduction; Leading Edges; Flapping; Wing Flaps; Aerodynamic Configurations
20050192627 NASA Langley Research Center, Hampton, VA, USA
Experimental Development and Evaluation of Pneumatic Powered-Lift Super-STOL Aircraft
Englar, Robert J.; Campbell, Bryan A.; Proceedings of the 2004 NASA/ONR Circulation Control Workshop, Part 1; June 2005, pp. 101-139; In English; See also 20050192624; Original contains color and black and white illustrations; No Copyright; Avail: CASI; A03, Hardcopy
The powered-lift Channel Wing concept has been combined with pneumatic Circulation Control aerodynamic and propulsive technology to generate a Pneumatic Channel Wing (PCW) configuration intended to have Super-STOL or VSTOL capability while eliminating many of the operational problem areas of the original Channel Wing vehicle. Wind-tunnel development and evaluations of a PCW powered model conducted at Georgia Tech Research Institute (GTRI) have shown substantial lift capabilities for the blown configuration (CL values of 10 to 11). Variation in blowing of the channel was shown to be more efficient than variation in propeller thrust in terms of lift generation. Also revealed was the ability to operate unstalled at very high angles of attack of 40 deg - 45 deg, or to achieve very high lift at much lower angle of attack to increase visibility and controllability. In order to provide greater flexibility in Super-STOL takeoffs and landings, the blown model also displayed the ability to interchange thrust and drag by varying blowing without any moving parts. A preliminary design study of this pneumatic vehicle based on the two technologies integrated into a simple Pneumatic Channel Wing configuration showed very strong Super-STOL potential. This paper presents these experimental results, discusses variations in the configuration geometry under development, and addresses additional considerations to extend this integrated technology to advanced design studies of PCW-type vehicles. Author
Short Takeoff Aircraft; Models; Aerodynamic Configurations; Aerodynamic Drag; Channel Wings
20050192632 NASA Langley Research Center, Hampton, VA, USA
Experimental Investigation of a Morphing Nacelle Ducted Fan
Kondor, Shayne A.; Moore, Mark; Proceedings of the 2004 NASA/ONR Circulation Control Workshop, Part 1; June 2005, pp. 435-468; In English; See also 20050192624; Original contains color illustrations Contract(s)/Grant(s): NAG1-02093; No Copyright; Avail: CASI; A03, Hardcopy
The application of Circulation Control to the nacelle of a shrouded fan is proposed as a means to enhance off-design performance of the shrouded fan.
Typically, a fixed geometry shroud is efficient at a single operating condition. Modifying circulation about the fixed geometry is proposed as a means to virtually morph the shroud without moving surfaces. This approach will enhance off-design-point performance with minimal complexity, weight, and cost. Termed the Morphing Nacelle, this concept provides an attractive propulsion option for Vertical Take-off and Landing (VTOL) aircraft, such conceptual Personal Air Vehicle (PAV) configurations proposed by NASA.
An experimental proof of concept investigation of the Morphing Nacelle is detailed in this paper.
A powered model shrouded fan model was constructed with Circulation Control (CC) devices integrated in the inlet and exit of the nacelle. Both CC devices consisted of an annular jet slot directing a jet sheet tangent to a curved surface, generally described as a Coanda surface. The model shroud was tailored for axial flight, with a diffusing inlet, but was operated off-design condition as a static lifting fan.
Thrust stand experiments were conducted to determine if the CC devices could effectively improve off-design performance of the shrouded fan. Additional tests were conducted to explore the effectiveness of the CC devices a means to reduce peak static pressure on the ground below a lifting fan.
Experimental results showed that off-design static thrust performance of the model was improved when the CC devices were employed under certain conditions. The exhaust CC device alone, while effective in diffusing the fan exhaust and improving weight flow into shroud inlet, tended to diminish performance of the fan with increased CC jet momentum. The inlet CC device was effective at reattaching a normally stalled inlet flow condition, proving an effective means of enhancing performance. A more dramatic improvement in static thrust was obtained when the inlet and exit CC devices were operated in unison, but only over a limited range of CC jet momentum. Operating the nacelle inlet and exit CC devices together proved very effective in reducing peak ground plane static pressure, while maintaining static thrust. The Morphing Nacelle concept proved effective at enhancing off-design performance of the model; however, additional investigation is necessary to generalize the results. Author
Experimentation; Ducted Fans; Control Equipment; Circulation Control Rotors; Nacelles
20050192634 Virginia Polytechnic Inst. and State Univ., Blacksburg, VA, USA
Numerical Analysis of Circulation Control on a NCCR 1510-7607N Airfoil using RANS Models
Viswanathan, Aroon K.; Tafti, Danesh K.; Proceedings of the 2004 NASA/ONR Circulation Control Workshop, Part 1; June 2005, pp. 197-226; In English; See also 20050192624; Original contains color and black and white illustrations; No Copyright; Avail: CASI; A03, Hardcopy
Numerical predictions of the lift augmentation and circulation control have been presented for a NCCR 1510-7607N airfoil using Reynolds-Averaged Navier Stokes (RANS) equations. Computations have been carried out for an airfoil at 0 angle-of-attack with the Reynolds number (based on chord length, c) of 5.45 x 10(exp 5). The effects of trailing edge wall jets have been studied and two different blowing rates have been simulated to show the effect of the jet momentum on the lift characteristics. Computations have been carried out for a fixed slot height (h/c = 0.003). Numerical solutions obtained using kappa-omega RANS model are compared with experimental results. The results show very good agreement of the pressure and the lift coefficients with the experimental values, at the low blowing rate case, while showing reasonable agreement at the high blowing ratio. Author
Numerical Analysis; Circulation Control Airfoils; Aerodynamic Coeffýcients; Lift Augmentation; Navier-Stokes Equation
20050194604 National Oceanic and Atmospheric Administration, Washington, DC, USA
NOAA Light Aircraft Forum. Session Results, November 15-16, 2001
January 2001; 40 pp.; In English Report No.(s): PB2005-107251; No Copyright; Avail: CASI; A03, Hardcopy
November 15-16, the Light Aircraft Workshop was focused on gathering the inputs of light aircraft users and service providers on: New light aircraft opportunities in NOAA. Desirable capabilities to which NOAA Line Offices would like access. Existing or future changes in technology and the impact on future requirements. Performance measures for OMAO. Expectations of OMAO. The workshop was structured to achieve maximum participation and input. Six tables with 5 participants each, representing a cross section of NOAA Line Offices and OMAO personnel, were challenged with the tasks to formulate responses and to offer top 5 priorities for each of the 5 topics. NTIS
Light Aircraft; Meteorological Research Aircraft; Data Acquisition
Source: NASA.
|
IHS sells products and services designed to meet the needs of today's aviation & aerospace engineers, including:
- Quick access to FAA, JAA, ICAO and UK-CAA information and regulations.
- Validated engineering methods, data, principles, worked examples, programs and related equations on over 1340 specific aerospace, process, structural and mechanical engineering topics.
- The IHS Fasteners eCatalog, providing decision support for the identification, specification and sourcing of aerospace & defense standard fasteners/hardware such as bolts, screws, nuts, washers, rivets, studs, etc.
- Standards documents and collections from the top aerospace & aviation standards development organizations, including SAE International, AIAA, AIA, FAA and NASA.
|