| A New On-Board Gauge Calibration Process for Aircraft Engine Testing |
27 AUG 2003 |
12 pages |
| Authors:
Jean-Pierre Lombard; Eric Seinturier; Marc Berthillier; SOCIETE NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION MOISSY-CRAMAYEL (FRANCE)
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 | A new procedure for calibrating on-board gauges on the blade assemblies of turbomachines is proposed in this paper. The calibration of an engine gauge, determined a priori during a component dynamic test, makes it possible to establish the levels of dynamic stress on the entire instrumented airfoil (based on the readings output by the gauge during the engine test). The method proposed is based on the use of holographic dynamic ... |
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| Nonlinear Computational Aeroelasticity: Formulations and Solution Algorithms |
27 AUG 2003 |
13 pages |
| Authors:
A. Soulaimani; A. BenElhajAli; Z. Feng; ECOLE DE TECHNOLOGIE SUPERIEURE MONTREAL (QUEBEC) DEPT DE GENIE MECANIQUE
|
| This paper highlights some technical features of an analysis methodology being developed for nonlinear computational aeroelasticity. A conservative finite element formulation for the coupled fluid/mesh interaction problem is proposed. Fluid-structure coupling algorithms are then discussed with some emphasis on distributed computing strategies. Numerical results are finally shown for the Agard 445.6 wing. |
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| Air Force Fast Center for Lightweight Structural Materials and Processing |
14 AUG 2003 |
106 pages |
| Authors:
Paul O. Biney; Jianren Zhou; Laura Carson; PRAIRIE VIEW A AND M UNIV TX
|
| The sixth year of the FAST Center at Prairie View A&M University was mainly devoted to the continuation of research in polymer processing and characterization, and mechanical and microstructural characterization, and a study of environmental effects on the properties of composites. |
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| Occupational Survey Report, AFSC 2A6X4, Aircraft Fuel Systems |
12 AUG 2003 |
44 pages |
| Authors:
Scott Vap; AIR EDUCATION AND TRAINING COMMAND RANDOLPH AFB TX
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| Presentation of findings from Occupational Survey Report for AFSC 2A6X4, Aircraft Fuel Systems. |
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| Aircraft Turbofan Engine Health Estimation Using Constrained Kalman Filtering |
AUG 2003 |
13 pages |
| Authors:
Dan Simon; Donald L. Simon; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH GLENN RESEARCH CENTER
|
| Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops an analytic method of incorporating state ... |
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| Hybrid Control of Jet Flows |
31 JUL 2003 |
29 pages |
| Authors:
Jonathan W. Naughton; Douglas R. Smith; WYOMING UNIV LARAMIE DEPT OF MECHANICAL ENGINEERING
|
| The use of swirl and synthetic jet actuators in a hybrid control scheme is described. The results here are limited to the characterization of (1) swirling jet flows and (2) synthetic jets in a two-dimensional mixing layer. Jets with swirl numbers of 0.10 and 0.23 with different tangential velocity profiles were studied. The lower swirl jets behaved similarly to non-swirling jets, whereas the higher swirl jets enhanced mixing significantly, up ... |
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| FlexTAC: An Advanced Submarine Control Surface and Actuation System |
JUL 2003 |
39 pages |
| Authors:
Scott Gowing; Bernie Carpenter; Yu T. Lee; Paisan Atsavapranee; David Hess; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD POPULATION AND FLUIDSSYSTEMS DEPT
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| An electrically-actuated flexible tab was tested on a model of a submarine sternplane comprised of a fixed stabilizer with a hinged flap. The tab was built into the trailing edge of the flap and was tested for its ability to control overall lift and reduce the torque required to rotate the flap itself. Shape memory alloy wires, embedded in a flexible silicone compound along the length of the tab, pulled ... |
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| Multidisciplinary Optimization of an Aircraft Wing/Tip Store in the Transonic Regime |
JUL 2003 |
38 pages |
| Authors:
Srinivasan Janardhan; Ramana V. Grandhi; WRIGHT STATE UNIV DAYTON OH DEPT OF MECHANICAL AND MATERIALS ENGINEERING
|
| In this research, a multidisciplinary optimization procedure is described to delay the occurrence of store-induced flutter of an aircraft wing/ tip store configuration. A preliminary design procedure was developed to enhance the performance characteristics of an aircraft wing model in the transonic Mach number regime. A wing/tip store configuration with the store center of gravity (c.g.) located at the 50% aerodynamic tip chord was chosen for structural optimization. The aircraft ... |
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| Dynamics and Control of Nonlinear Fluid-Structure Interaction |
JUL 2003 |
16 pages |
| Authors:
Earl H. Dowell; Robert L. Clark Jr.; Lawrence N. Virgin; DUKE UNIV DURHAM NC DEPT OF MECHANICALENGINEERING AND MATERIALS SCIENCE
|
| Experimental and theoretical studies of the nonlinear dynamics and control of aeroelastic systems including airfoils and wings have been conducted. Nonlinear geometric stiffness and freeplay have been considered specifically and good theoretical / experimental correlation obtained. Active control systems have been designed, built and tested to increase flutter speed and reduce limit cycle oscillations (LCO). Our most recent work includes theoretical studies of aerodynamic nonlinearities in the transonic range and ... |
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| Nondestructive Evaluation (NDE) Technology Initiative Program (NTIP). Delivery Order 0038: NDE Sensory Monitoring System for Aircraft Structure |
JUL 2003 |
37 pages |
| Authors:
M. Sundaresan; G. Grandhi; S. Uppaluri; J. Kermerling; NORTH CAROLINA AGRICULTURAL AND TECHNICAL STATE UNIV GREENSBORO DEPT OF MECHANICAL ENGINEERING
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| The concept of a biomimetic sensor system design that can be embedded in aircraft structure is explored in this project. Signal processing techniques for quantifying the sensor responses are studied. In particular, wavelet analysis is used to extract the time frequency information about the acoustic emission (AE) signals and to separate the Lamb wave modes. The continuous sensor used in this biomimetic sensor system was used to monitor fatigue crack ... |
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| Computational Mechanics Approach for Multidisciplinary Nonlinear Sensitivity Analysis |
30 JUN 2003 |
8 pages |
| Authors:
Ramana V. Grandhi; WRIGHT STATE UNIV DAYTON OH DEPT OF MECHANICAL AND MATERIALS ENGINEERING
|
| The primary objective of this research work was to develop preliminary designs of aircraft wing/store configurations to achieve improved flutter performance in the transonic regime. In this research work, a methodology was developed to incorporate the nonlinearities associated with the wing and store in transonic regime into the multidisciplinary environment. Investigated the aeroelastic effects of the wing with and without the inclusion of store aerodynamics. The tip store configurations and ... |
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| Energy Based Design and Control for Innovative Air Vehicle Concepts |
30 JUN 2003 |
15 pages |
| Authors:
Gregory Washington; OHIO STATE UNIV COLUMBUS
|
| In nature, birds change shape of their wings to achieve proper flight performance. In fact a falcon can glide or loiter at tremendous heights and then dive at three times its gliding speed to strike its prey. Falcons are able change the geometry of their wings by bending them at the shoulder, elbow and wrist. They can also affect the camber of the wing, and even articulate feathers at the ... |
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| Considerations for the Maneuver Commander: Could the Emergence of Unmanned Aerial Vehicles Spell the Demise of the Army's RAH-66 Comanche in the Armed Reconnaissance Role? |
06 JUN 2003 |
102 pages |
| Authors:
David W. Barnes; ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS
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| The U.S. Army finds itself at a crossroad in the development and fielding of both unmanned aerial vehicles (UAVs) and the RAH-66 Comanche helicopter to fulfill the armed reconnaissance role for its future Objective Force (OF). Ever-increasing UAV capabilities, especially the ability to arm these platforms with Hellfire missiles, is forcing a blending of roles that were once solely the domain of manned platforms. This paper attempts to answer the ... |
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| Reduction of Thermal Residual Strains in Adhesively Bonded Composite Repairs |
JUN 2003 |
138 pages |
| Authors:
Heather R. Crooks; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Many military and commercial aircraft are being called upon to fly well beyond their original intended service lives. This has forced the United States Air Force (USAF) to increasingly rely on structural repairs to address fatigue induced damage and to extend aircraft useful life. The focus of this research is the use of a high-strength composite patch technique to repair a fatigue crack on an aluminum aircraft structure. This study ... |
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| Barriers to Lean Enterprise Transformation: A Case Study of the F-16 Avionics Sustainment System |
JUN 2003 |
|
| Authors:
Benjamin M. Brandt; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
 | Instituting basic principles of lean thinking can help transform the U.S. Air Force's sustainment system by substantially improving its efficiency and effectiveness. One of the immediate outcomes of viewing the sustainment system through 'lean lenses' is the identification of numerous barriers impeding the system's transformation. These barriers are caused by a complex array of institutional, organizational, financial, technological, and policy and regulatory structures, as well as practices, established by the ... |
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| Vertical Tail Dynamic Response in Vortex Breakdown Flow |
JUN 2003 |
|
| Authors:
Oleg Levinski; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
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| The paper describes the development of an aeroelastic model for the prediction of empennage dynamic response due to vortex induced buffet loads. The multidisciplinary problem of tail buffeting is solved accurately in the time domain using an unsteady vortex model for prediction of aerodynamic loads and coupled aeroelastic equations for the bending and torsional deflections of the tail which are resolved using the Galerkin method. A dynamic aeroelastic analysis of ... |
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| DEF STAN 00-970 Requirements for the Design and Airworthiness of Composite Aircraft Structure |
JUN 2003 |
|
| Authors:
Paul J. Callus; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
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| One of the impediments to the introduction of composite structure into Australian Defence Force (ADF) aircraft is the difficulty in identifying those airworthiness requirements specific to these materials. The ADF uses a comparative approach where tenderers propose their own certification basis. This is assessed against the ADF comparative certification basis to ensure that all relevant issues are covered in adequate depth. The ADF comparative certification basis is DEF STAN 00-970 ... |
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| Reliability Analysis of the 4.5 Roller Bearing |
JUN 2003 |
83 pages |
| Authors:
Cole Miller; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The J-52 engine used in the EA-6B Prowler has been found to have a faulty design which has led to in-flight engine failures due to the degradation of the 4.5 roller bearing. Because of cost constraints, the Navy developed a policy of maintaining rather than replacing the faulty engine with a re-designed engine. With an increase in Prowler crashes related to the failure of this bearing, the Navy has begun ... |
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| A Three-Dimensional Flutter Theory For Rotor Blades With Trailing-Edge Flaps |
JUN 2003 |
237 pages |
| Authors:
Mark A. Couch; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This dissertation develops the equations of motion for the structural and aerodynamic forces and moments of a rotor blade with a trailing-edge flap using eight degrees of freedom. Lagrange's equation is applied using normal modes to find the flutter frequency and speed similar to the classic fixed-wing method developed by Smilg and Wasserman. However, rotary-wing concerns are addressed including different freestream velocities along the blade (variation of reduced frequency along ... |
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| Cognitive Issues Related to Advanced Cockpit Displays: Supporting the Transition between Internal and External Guidance |
Jun-2003 |
113 pages |
| Authors:
Maura C Lohrenz; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| A critical issue in military aviation is the pilot's ability to transition between primarily internal (head-down, instrument-driven) and external (head-up, out of the cockpit) guidance. Experimental cockpit displays were designed and tested for how well they might support this transition phase for military pilots performing time-critical air-to-ground targeting missions such as Forward Air Control and Close Air Support. Twelve subjects performed three sets of experiments using a flight simulator (with ... |
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| Evaluating Operational Readiness For Fixed-Wing Tactical Aviation Units |
22 MAY 2003 |
81 pages |
| Authors:
Jeffrey L. Hoing; SETON HALL UNIV SOUTH ORANGE NJ DEPT OF BIOLOGY
|
| The Marine Corps has used the Marine Corps Combat Readiness Evaluation System (MCCRES) and Commanding General's Inspections (CGI) to evaluate fixed-wing tactical aviation unit readiness for over 25 years. While these systems have served the Marine Corps well, they need to be analyzed to determine how effectively they measure operational readiness in today today's environment. Analysis in this monograph concludes that the MCCRES, while sound as a framework for evaluating ... |
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| The Aviation Detachment in the U.S. Army's Unit of Action: Full Spectrum Dominance |
22 MAY 2003 |
61 pages |
| Authors:
Mark A. Moser; ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS SCHOOL OF ADVANCED MILITARY STUDIES
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| This paper examines the currently proposed composition of the U.S. Army's Unit of Action Aviation Detachment, twelve Comanches and eight TUAVs, and attempts to evaluate this mix of platforms to determine if it will provide the Unit of Action commander with the right tools to shape his fight. In order to make this evaluation, empirical data from Aviation and Troop Command / Joint Combat And Tactical Simulation (ATCOM / JCATS) ... |
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| Dynamics and Control of Fluid-Structure Interaction |
20 MAY 2003 |
159 pages |
| Authors:
Robert L. Clark; DUKE UNIV DURHAM NC DEPT OF MECHANICALENGINEERING AND MATERIALS SCIENCE
|
| The primary objective of the research program was to advance a fundamental method of developing dynamic models of fluid-structure interaction which capture the essential physics required to design and evaluate the application of adaptive structures for the control of aeroelastic, structural acoustic, and coupled aeroelastic, structural acoustic systems. Analytical, numerical, and experimental procedures were conducted as part of the research effort. A total of eight journal papers were published and ... |
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| The Aeroelastic Effects of Transverse Shear Deformation on Composite Wings in Various Speed Flow Regimes |
02 MAY 2003 |
70 pages |
| Authors:
Michael Oliver; NAVAL ACADEMY ANNAPOLIS MD DEPT OF AEROSPACE ENGINEERING
|
| This project analyzes the effect of transverse shear deformation upon the aeroelastic response of composite wings in high speed flow regimes. Previously, models were developed to predict the aeroelastic characteristics of classical materials in high speed flow. However, these studies ignored transverse shear by assuming an infinite modulus of rigidity. This assumption underestimates transverse flexibility by ignoring the transfer of loads through the wing thickness. By assuming a finite modulus ... |
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| Enhancing U.S. Army Aircrew Coordination Training |
MAY 2003 |
32 pages |
| Authors:
Lawrence C. Katz; Gary N. Grubb; ARMY RESEARCH INST FOR THE BEHAVIORAL AND SOCIAL SCIENCES ALEXANDRIA VA
|
| The US Army defines aircrew coordination as a set of principles, attitudes, procedures, and techniques that transforms individuals into an effective crew. The stated objective of Aircrew Coordination Training (ACT) is to provide aircrews the knowledge, skills and attitudes necessary to increase their mission effectiveness, while decreasing the errors that lead to accidents. ACT and Crew/Cockpit Resource Management (CRM) programs were instituted in the 1980's, first in commercial aviation and ... |
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| Dynamic Aeroelastic Instabilities of an Aircraft Wing with Underwing Store in Transonic Regime |
MAY 2003 |
31 pages |
| Authors:
Chakradhar Byreddy; Ramana V. Grandhi; Philip Beran; ADVANCED STRATEGIC AND TACTICAL INFRARED EXPENDABLES OFFICE WRIGHT-PATTERSONAFB OH
|
| The research used the Transonic Small Disturbance (TSD) theory to better understand the dynamic aeroelastic phenomena and factors that affect the onset of flutter and store induced Limit-Cycle Oscillations (LCO) in the transonic regime. Several parametric studies of the flutter and LCO of an aircraft wing with underwing store in the transonic regime were conducted, as well as an investigation of the effect of inclusion of store aerodynamics on the ... |
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| A Review of Australian and New Zealand Investigations on Aeronautical Fatigue During the Period April 2001 to March 2003 |
APR 2003 |
|
| Authors:
Graham Clark; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
|
| This document has been prepared for presentation to the 28th Conference of the International Committee on Aeronautical Fatigue scheduled to be held in Lucerne Switzerland, 5th and 6th May 2003. Brief summaries and references are provided on the aircraft fatigue research and associated activities of research laboratories, universities, and aerospace companies in Australia and New Zealand during the period April 2001 to March 2003. The review covers fatigue-related research programs ... |
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| Joint Strike Fighter Integrated Subsystem Technology (J/IST) demonstration Program. Execution and Management of a Technology Maturation Program Conducted by Industry, for Industry |
APR 2003 |
18 pages |
| Authors:
Alan Burkhard; Richard Deitrich; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| The Joint Strike Fighter (JSF) Integrated Subsystems Technology (J/ IST) Demonstration Program was a highly successful industry- wide five-year program in which normally competitive JSF Weapon System Contractors (WSCs) and suppliers worked together with competitors to accomplish technology maturation and mitigate technological risks of a revolutionary subsystem concept for tactical aircraft that integrates the subsystems and utility functions thereby reducing the associated major equipment groups from 13 to 5. |
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| Path Planning for Sensing Multiple Targets from an Aircraft |
APR 2003 |
138 pages |
| Authors:
Jason K. Howlett; BRIGHAM YOUNG UNIV PROVO UT DEPT OF MECHANICAL ENGINEERING
|
| To generate an assignment of tasks that best utilizes a team's resources, it is necessary to know the costs incurred by a team member for doing those tasks. In a cooperative search and destroy scenario, tasks generally require that the vehicle's sensor pass over specific known target points, which, to produce the associated costs, requires calculating the path the vehicle will take to sense the various targets. When the targets ... |
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| Multimission Aircraft Design Study: Electromagnetic Compatibility |
25 MAR 2003 |
129 pages |
| Authors:
Jenna M. Davis; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The multi-mission aircraft (MMA) technical feasibility study looked at the replacement of the aging fleet of C-135 and C-130 theater based command & control (C2) and intelligence, surveillance and reconnaissance (ISR) fleet. It is proposed that the MMA be out-fitted to combine some or all the functions of existing AWACS, JSTARS, RIVET JOINT, COMPASS CALL, and ABC CC platforms. It would also have links to other manned or unmanned ISR ... |
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| The Measurement of Trace Metals in JP-8 by ICP-OES |
13 MAR 2003 |
16 pages |
| Authors:
Timothy J. Shelley; Christian Voelkl; AIR FORCE RESEARCH LAB TYNDALL AFB FL MATERIALS AND MANUFACTURING DIRECTORATE
|
| JP-8 is the preferred fuel for Air Force transport and fighter aircraft. In general, JP-8 acceptance specifications focus on physical properties of the fuel such as vapor pressure, boiling range, and thermal stability. Very little work has been performed to identify and measure the metals that may be present in JP-8 at an operating airbase. There is an interest in the catalytic processing of JP-8 into other materials as a ... |
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| Sensor-Craft Analytical Certification |
10 MAR 2003 |
110 pages |
| Authors:
Ronald W. Roberts Jr.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This study developed a multi-disciplinary conceptual design of a joined-wing sensor-craft. Initial analysis was conducted using an aluminum model. Linear fully stressed design and flexible aerodynamic trim were used to converge to a minimum weight design that was aerodynamically stable. This optimized design was buckling safe. A similar optimization process using non- linear fully stressed design and flexible aerodynamic trim was conducted. The non- linear structurally deformation was over ten ... |
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| Structurally Integrated Antennas on a Joined-Wing Aircraft |
MAR 2003 |
88 pages |
| Authors:
Ben P. Smallwood; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This research is a foundational study of conformal, load-bearing antenna arrays embedded into the wing structure of a joined-wing aircraft. It is a muiltidisciplinary effort that touches on the aerodynamic structural and electromagnetic design considerations that stem from this unique type of sensor integration. The antenna performance Finite Element Model (FEM) and control surface effectiveness are investigated. The theory describing an ensemble of dipole antenna elements that conform to the ... |
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| Aerospace Ground Equipment Management's Impact on Home-Station Sortie Production |
MAR 2003 |
116 pages |
| Authors:
Michael A. Bayer; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Since the Air Force began its evolution into an Expeditionary Air Force, much effort has been expended in attempt to optimize the compositions of each Air Expeditionary Force (AEF) and the manner in which an AEF deploys. Air Force plans were previously based upon deploying 24-ship Unit Type Codes (UTC), although a 12-ship deployment is more prevalent in today's environment. In an effort to eliminate the anomalies between planned and ... |
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| Multimission Aircraft Design Study-Operational Scenarios |
MAR 2003 |
156 pages |
| Authors:
Nevin Coskuner; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| In the most recent years, the Command, Control and Communications, Counter Measures, Intelligence, Surveillance and Reconnaissance (C3CMISR) aircrafts are used commonly in many NATO and UN Operations around the world. These aircrafts are AWACS, JSTARS, Rivet Joint, Compass Call and ABCCC. They provide close air support in the name of airborne surveillance, ground moving target surveillance, target reconnaissance, jamming, and command, control and communications issues in operational environments. Those aircrafts ... |
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| Calculation of the Actual Cost of Engine Maintenance |
MAR 2003 |
101 pages |
| Authors:
Oguz Ezik; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The cost of military operations has been difficult to determine, yet considered of high importance. The cost of an operation is largely dependant upon the answers to subordinate questions involving the discrete costs of military activities, like supporting individual items, While different cost estimates have received attention from the media, the question arises as to how accurate these figures are, There have been numerous studies performed by the Operations Research ... |
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| Simulation of Autonomic Logistics System (ALS) Sortie Generation |
MAR 2003 |
104 pages |
| Authors:
Paul D. Faas; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The Air Force needs tools for analysis and evaluation of new logistic operational concepts. The purpose of this research was to conflict a discrete event simulation model of the aircraft sortie generation process to permit what- if analyses of these concepts. The current Air Force logistics operations system is reactive in nature meaning that after the aircraft detects a part failure, the maintenance person must perform fault isolation procedures and ... |
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| Computational Fluid Dynamics Investigation of Vortex Breakdown for a Delta Wing at High Angle of Attack |
MAR 2003 |
172 pages |
| Authors:
Jacob A. Freeman; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Using the commercially available FLUENT 3-D flow field solver, this research effort investigated vortex breakdown over a delta wing at high angle of attack (a) in preparation for investigation of active control of vortex breakdown using steady, along- core blowing A flat delta-shaped half-wing with sharp leading edge and sweep angle of 600 was modeled at a 180 in a wind tunnel at Mach 0,04 and Reynolds number of 3,4 ... |
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| Practices and Perspectives in Outsourcing Aircraft Maintenance |
MAR 2003 |
72 pages |
| Authors:
Edward Czepiel; NORTHWESTERN UNIV EVANSTON IL TRANSPORTATION CENTER
|
| The objective of this study was to identify the most common criteria that airlines use to select, monitor, and assess the performance of third-party maintenance facilities. These criteria formed the basis to develop performance measures and risk indicators for the operation of aviation maintenance repair stations. In particular, this study focused on outsourcing of major maintenance to larger repair stations. A limited data collection effort was conducted by interviewing representatives ... |
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| A Comparison of Nonlinear Algorithms to Prevent Pilot-Induced Oscillations Caused by Actuator Rate Limiting |
MAR 2003 |
107 pages |
| Authors:
James G. Henley; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The objective of this study was to compare the ability of the Feedback-with-Bypass (FWB) and the Derivative-Switching (DS) flight control system filters to prevent PIO during actuator rate limiting, and the filters' effects on aircraft handling qualities. This comparison was conducted in three steps: computer simulation, ground simulation in the Large Amplitude Multimode Aerospace Research Simulator (LAMARS), and flight tests conducted in the Variable Stability In-flight Simulator Test Aircraft (VISTA). ... |
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| Analysis of Broadband High-Impedance Ground Plane Antenna Designs |
MAR 2003 |
86 pages |
| Authors:
James W. Stewart; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This research ties together computational and experimental analysis of two types of high-impedance ground plane (HIGP) antennas, One type of antenna consists of a proposed two-layer design. The structure consists of a bowtie antenna mounted over the surface of a HIGR The proposed structure was intended to achieve a resonant frequency of 3 GHz and a bandwidth of 48%; however, a design error results in a significant mismatch in operating ... |
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| Reduction of Military Vehicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation (La reduction des couts et des delais d'acquisition des vehicules militaires par la modelisation avancee et la simulation de produit virtuel) |
MAR 2003 |
|
| Authors:
NATO RESEARCH AND TECHNOLOGY ORGANIZATION NEUILLY-SUR-SEINE (FRANCE)
|
| Integrated weapon systems modeling and simulation from concept to operation were treated as essential tool for achieving cost and time reductions which are needed to field new systems. Such tools are being applied to lower the cost and design cycle times from both a design/development and recurring manufacturing perspective. Early identification of problems dramatically reduces costs and improves procurement as well as operations, increasing performance as well as cost effectiveness. ... |
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| Point of Maintenance Hurlburt Initial Structured Study Test Report |
MAR 2003 |
26 pages |
| Authors:
Megan Gorman; Carlton Donahoo; Laurie Quill; Johnnie Jernigan; Matthew W. Goddard; DAYTON UNIV OH RESEARCH INST
|
| 13 ABSTRACT (Maximum 200 words) This document describes the usability test conducted by the Air Force Research Laboratory, Logistics Readiness Branch (AFRL/HESR) and the University of Dayton Research Institute (UDRI) to assess user performance with the Point of Maintenance (POMX) system for maintenance data collection on the flightline. This test consisted of observations of task performance in baseline Corps Automated Maintenance System (CAMS) and batch POMX conditions, and feedback questionnaires ... |
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| Axisymmetric and Non-Axisymmetric Initiation of Vortex Breakdown |
MAR 2003 |
20 pages |
| Authors:
Andrew W. Cary; David L. Darmofal; BOEING CO ST LOUIS MO
|
| The onset of axisymmetric (bubble) and non-axisymmetric (spiral) modes of breakdown is studied numerically for swirling pipe flows. The authors have found that the onset of axisymmetric vortex breakdown occurs when the vortex attains local criticality. A transient simulation of the evolution of vortex breakdown revealed that downstream-running waves are trapped approximately at the location of flow criticality. These trapped waves are slowly amplified and eventually result in the bubble ... |
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| Technical Evaluation Report, Part A - Vortex Flow and High Angle of Attack |
MAR 2003 |
27 pages |
| Authors:
James M. Luckring; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
|
| A symposium entitled Vortex Flow and High Angle of Attack was held in Loen, Norway, from May 7 through May 11, 2001. The Applied Vehicle Technology (AVT) Panel, under the auspices of the Research and Technology Organization (RTO), sponsored this symposium. Forty-eight papers, organized into nine sessions, addressed computational and experimental studies of vortex flows pertinent to both aircraft and maritime applications. The studies also ranged from fundamental fluids investigations ... |
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| Effects of Various Fillet Shapes on a 76/40 Double Delta Wing from Mach 0.18 to 0.7 |
MAR 2003 |
41 pages |
| Authors:
Hugo A. Gonzalez; Gary E. Erickson; Blair G. McLachlan; James H. Bell; NAVAL AIR STATION PATUXENT RIVER MD
|
| The objective of this experimental investigation was to understand the impact of small geometry modifications (fillets) at the juncture of a 76 degree sweep leading edge extension (LEX) or strake and a 40 degree sweep cropped delta wing (76/40 double delta wing). A sharp leading edge model was used to depict a generic fighter strake and wing configuration. These fillets were developed to control the shedding, trajectory, and subsequent breakdown ... |
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| Military Vortices |
MAR 2003 |
13 pages |
| Authors:
D. A. Lovell; QINETIQ LTD FARNBOROUGH (UNITED KINGDOM)
|
| The flow control methods being exploited by Micro-electro-mechanical systems (MEMS) devices rely in many cases on the manipulation of small-scale vortices to provide favorable mixing effects. By appropriate design and siting of MEMS very local effects on the flow can be made to provoke large-scale changes in the flow structure and, for example, control the conditions at which the flow separates. This topic area will not be considered further in ... |
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| An Experimental Investigation of Leading Edge Vortices and Passage to Stall of Nonslender Delta Wings |
MAR 2003 |
17 pages |
| Authors:
Michael V. Ol; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AIR VEHICLES DIRECTORATE
|
| This paper describes an experimental investigation of the structure and decay of the leading edge vortices (LEVs) produced by a nonslender delta wing. The work was conducted in a water tunnel facility at the California Institute of Technology and was sponsored by the Air Force Research Laboratory (AFRL). Stereoscopic digital particle image velocimetry was used to obtain three-component velocity data in planar slices across the flow field above the wing ... |
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| Experimental Investigation of Vortex Breakdown over a Delta Wing with Consideration of Control by Fluid Injection |
MAR 2003 |
15 pages |
| Authors:
P. Molton; A. Mitchell; D. Barberis; D. Afchain; O. Rodriguez; ONERA-MEUDON CENTRE MEUDON (FRANCE) FUNDAMENTAL/EXPERIMENTAL AERODYNAMICS DEPT
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| It is well-known that at high angles of attack, multiple vortex structures form on the wing due to the rolling-up of the viscous shear layers that separate from the upper surface. The highest energy structures result from separation along the so-called primary separation line, which is the leading edge, if it is sharp or highly curved. The intensity of this main vortex increases with the angle of attack until a ... |
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| Prediction de l'Eclatement Tourbillonnaire sur les Ailes Delta d'Avions Militaires (CFD Prediction of Vortex Breakdown on Delta Wings for Military Aircraft) |
MAR 2003 |
11 pages |
| Authors:
Jean-Pierre Rosenblum; Jean-Max Hasholder; Jean- Claude Courty; Xavier Rocca; DASSAULT AVIATION SAINT-CLOUD (FRANCE)
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| If we want to control vortex breakdown on a delta wing of a military aircraft in order to create rolling moments or improve stability at high angle of attack. the use of CFD simulations may help us to improve our understanding of the flow mechanisms that occur with the use of specific control devices. The first step of such studies is to make sure that we can simulate properly and ... |
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Aircraft
