| System Identification Methods for Improving Flutter Flight Test Techniques |
AUG 2004 |
15 pages |
| Authors:
David Klyde; Chuck Harris; Peter M. Thompson; Edward N. Bachelder; AIR FORCE FLIGHT TEST CENTER EDWARDS AFB CA 412TH LOGISTICS GROUP
|
 | Classic flutter flight testing involves the evaluation of a given configuration at a stabilized test point before clearance is given to expand the envelope further. At each stabilized point flight test data are compared with computer simulation models to assess the accuracy of predicted flutter boundaries. Because of the time constraints associated with these procedures, the Air Force has been seeking methods to improve current flight test methods. This paper ... |
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| Computational Methods for Feedback Controllers for Aerodynamics Flow Applications |
29 JUL 2004 |
86 pages |
| Authors:
William Z. Strang; James R. Forsythe; Stefan Siegel; Thomas E. McLaughlin; Kelly Cohen; COBALT SOLUTIONS LLC SPRINGFIELD OH
|
| Report developed under STTR contract for topic AF03-T007. This document represents the final report of a phase I STTR program between the USAF Academy Department of Aeronautics and Cobalt Solutions, LLC. The goal of the STTR is to develop a set of computational design tools for closed loop flow control. These tools need to cover the entire design cycle from plant characterization through control system development to testing of the ... |
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| Membrane Wing Aerodynamics for micro AV Applications |
26 JUL 2004 |
27 pages |
| Authors:
Wei Shyy; Yongsheng Lian; Peter Ifju; FLORIDA UNIV GAINESVILLE MECHANICAL AND AEROSPACE ENGINEERING
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| Viewgraphs only of Membrane Wing Aerodynamics for micro AV applications. |
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| High Resolution Computational Unsteady Aerodynamic Techniques Applied to Maneuvering Unmanned Combat Aircraft |
26 JUL 2004 |
40 pages |
| Authors:
Scott Morton; AIR FORCE ACADEMY COLORADO SPRINGS CO
|
| Briefing charts from presentation on high resolution computational unsteady aerodynamic techniques as applied to maneuvering unmanned combat aircraft. |
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| Computational and Physical Aspects of UAV Vortical Flows |
26 JUL 2004 |
17 pages |
| Authors:
Miguel R. Visbal; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AIR VEHICLES DIRECTORATE
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| Briefing charts from presentation on the computational and physical aspects of UAV(unmanned air vehicle) vortical flows. |
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| UCAV Aerodynamics and Vehicle Control in the Naval Environment |
26 JUL 2004 |
31 pages |
| Authors:
Terence A. Ghee; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD
|
| Document contains specifications on aircraft structure, launch mechanisms, and recovery configurations. included are the advantages of an unmanned combat air vehicle plus the challenging concerns surrounding it. |
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| The Effects of Aerodynamic Jump Caused by a Uniform Sequence of Lateral Impulses |
JUL 2004 |
22 pages |
| Authors:
Gene R. Cooper; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The linear theory for spinning projectiles is extended to account for the application of a uniform sequence of lateral square impulses activated during free flight. Analytical results are shown to produce simple contributions to the familiar aerodynamic jump formulation for a single impulse. Inquiries regarding modifications of jump smearing are addressed, and comparative calculations are presented. The formulation shows that an additional jump phase angle and the jump magnitude are ... |
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| Wind Tunnel Simulations of the Mock Urban Setting Test - Experimental Procedures and Data Analysis |
JUL 2004 |
|
| Authors:
Ralph Gailis; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
|
 | The MUST experiment was a large outdoor field study in atmospheric dispersion, attempting to simulate an urban boundary layer by the construction of a regular array of shipping containers. The current report gives details of a wind tunnel dispersion study of the MUST array, aimed at bridging some of the gaps between laboratory and full-scale outdoor trials. The experimental setup and wind tunnel instrumentation are discussed in detail, the measurements ... |
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| Flow Control Enabled Aircraft Design |
JUL 2004 |
236 pages |
| Authors:
Rajendar K. Nangia; NANGIA AERO RESEARCH ASSOCIATES BRISTOL(UNITED KINGDOM)
|
| This report results from a contract tasking Nangia Aero Research Associates as follows: Many future advanced aircraft concepts being considered by the Air Force fall outside the current aerodynamic design practice and will rely heavily on the use of flow control technology to optimize flight performance. Examples include SensorCraft, long range strike aircraft, ultra STOL transports, and hypersonic aircraft. To properly design and optimize the aerodynamic performance of these vehicle ... |
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| Control of Systems With Periodic Coefficients, With Application To Active Rotor Control |
30 JUN 2004 |
174 pages |
| Authors:
Roberto Celi; Marco Lovera; Patrizio Colaneri; MARYLAND UNIV COLLEGE PARK DEPT OF AEROSPACE ENGINEERING
|
| The project focused on the analysis and synthesis of active rotor controls. The rotor was modeled as a periodic system. The key accomplishments are: (i) First systematic study of the effect of zeros in rotorcraft aeromechanics. The "zeros" play a key role in the closed-loop behavior of the system. As rotor active controls become feasible, the calculation of zeros needs to become a routine design step. (ii) First study of ... |
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| Plasma Aerodynamic Experiments |
22 JUN 2004 |
25 pages |
| Authors:
A. F. Aleksandrov; V. L. Bychkov; I. B. Timofeev; MOSCOW STATE LOMONOSOV UNIV (RUSSIA)
|
| As is well known plasma technologies nowadays find wide applications in aerodynamics, and it has become evident that development of hypersonic aviation is unlikely possible without application of plasma and beam technologies. In external aerodynamics can be applied for improvement of combustion processes due to usage of created volumetric plasma structures in the stagnation zone and directly in subsonic and supersonic air-fuel mixtures. Electrical gas discharges are promising methods of ... |
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| Use of Statistical Tools to Improve Modeling and Simulation of Store Separation |
01 JUN 2004 |
13 pages |
| Authors:
A. Cenko; A. Piranian; J. Rupert; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD
|
| The MK-82 Joint Direct Attack Munition (GBU-38) is cleared for carriage and employment for the entire F/A-18C aircraft flight envelop from the BRU-55 Canted Vertical Ejector Rack (CVER). The GBU-38 was certified for carriage and release through a series of flight tests. For the first flight where the store was released form the BRU-55, the wind tunnel Captive Trajectory System (CTS) data, as well as NAVAIR and Boeing pre-flight predictions, ... |
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| Relaxed Fidelity CFD Methods Applied to Store Separation Problems |
01 JUN 2004 |
27 pages |
| Authors:
Rudy Johnson; M. B. Davis; Dennis Finley; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AEROSPACE VEHICLE INTEGRATION AND DEMO BRANCH
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| The goal of relaxed fidelity computational fluid dynamics (CFD) methods is to provide a store separation analysis capability that lies between the accuracy-productivity characteristics of influence function methods and time-accurate CFD methods. Two methods are presented in this paper, both of which provide significant accuracy improvements over influence function methods while providing rapid enough turn around times to support parameter and design studies. The first technique discussed is the Minimized ... |
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| F-111 Store Trajectory Analysis |
01 JUN 2004 |
9 pages |
| Authors:
Rudy Johnson; Andrew Cary; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AEROSPACE VEHICLE INTEGRATION AND DEMO BRANCH
|
| The analysis of store separation by computational fluid dynamics (CFD) techniques holds great promise for reducing aircraft-store certification testing. The primary concern with CFD application is the question of accuracy. This question of how much confidence should be placed on CFD generated loads data and trajectories is addressed using an uncertainty analysis technique. The process requires a formalized approach to evaluating the uncertainty associated with CFD produced loads data. This ... |
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| Active Flow Control for High-Speed Weapon Release from a Bay |
01 JUN 2004 |
25 pages |
| Authors:
Valdis Kibens; William W. Bower; David R. Schwartz; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AIR VEHICLES DIRECTORATE
|
| In recent years work at the Air Force Research Laboratory Air Vehicles Directorate has focused on pursuing active flow control (AFC) devices for achieving better weapons bay control with regard to acoustic loads reduction and weapon separation characteristics than the control offered by passive devices (spoilers). This paper describes the Long Range Strike Aero Experiment which was a systematic study that pursued AFC actuators integrated in a 10%-scale weapons bay ... |
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| Synthetic Jet Actuation - Modeling, Actuator Development and Application to Separation Control |
JUN 2004 |
141 pages |
| Authors:
Othon K. Rediniotis; TEXAS ENGINEERING EXPERIMENT STATION COLLEGE STATION
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| This work presents an investigation of synthetic jet actuation for separation control over wings/airfoils, in steady and unsteady flows, the development of high-power, compact synthetic jet actuators (SJA) for flow separation control, the modeling and control of such actuators and the modeling and control of the resulting SJA-controlled aerodynamics and wing/airfoil, respectively. The developed actuator is compact enough to fit in the interior of a NACAOOl5 profiled wing with a ... |
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| Numerical Prediction of the Impact of Non-Uniform Leading Edge Coatings On the Aerodynamic Performance of Compressor Airfoils |
JUN 2004 |
91 pages |
| Authors:
Michael E. Elmstrom; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| A computational fluid dynamic (CFD) investigation is presented that provides predictions of the aerodynamic impact of uniform and non-uniform coatings applied to the leading edge of a compressor airfoil in a cascade. Using a NACA 65(12)10 airfoil, coating profiles of varying leading edge non-uniformity were added. This non-uniformity is typical of that expected due to fluid being drawn away from the leading edge during the coating process. The CFD code, ... |
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| Prediction of the Pitch-Damping Coefficients Using Sacks Relations |
JUN 2004 |
40 pages |
| Authors:
Paul Weinacht; James E. Danberg; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Throughout its development, slender body theory has been generalized to predict a large variety of aerodynamic coefficients for a wide class of flight bodies. For most applications, slender body theory provides only a qualitative predictive capability. There is, however, a set of slender body relationships which has been previously derived by Sacks that allows the individual pitchdamping coefficients and the pitch-damping coefficient sums to be related to each other. Until ... |
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| Aeroelastic Analysis of a Joined-Wing Sensorcraft |
JUN 2004 |
84 pages |
| Authors:
Jennifer J. Sitz; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
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| This study performed an aeroelastic analysis of a joined-wing SensorCraft. The analysis was completed using an aluminum structural model that was splined to an aerodynamic panel model. The force and pressure distributions were examined for the four aerodynamic panels: aft wing, fore wing, joint, and outboard tip. Both distributions provide the expected results (elliptical distribution), with the exception of the fore wing. The fore wing appears to be affected by ... |
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| Detached Eddy Simulation Analysis of Pak-B Low Pressure Turbine Blade |
JUN 2004 |
71 pages |
| Authors:
Kyle Malone; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Two cases were computationally investigated using the detached eddy simulation (DES) turbulence model: an unmodified Pak-B blade and a Pak-B blade with a dimple located at 65% of axial chord. Both cases were created so that they simulated an infinite span with an infinite number of dimples. The cases were run for an inlet Reynolds number of 25,000. The computed results were used to resolve the location of separation and ... |
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| Air Data System Calibration of F-16B S/N 92-0457 (Project TRUE Phoenix) |
JUN 2004 |
116 pages |
| Authors:
Brian D. Griffin; Scott A. Dickson; Jason T. DiGiacomo; Paul K. Harmer; Gregory A. Grimes; AIR FORCE TEST PILOT SCHOOL EDWARDS AFBCA
|
| This report presents the results of a limited air data system calibration on F-16B S/N 92-0457. The position error corrections, total pressure error. total air temperature probe recovery factor, and angle of attack effects were determined though flight test and are presented in this report, Testing began on 7 April and was completed on 30 April 2004 after eight missions. |
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| DSPFRC - Force and Moment Data Display and Monitoring Program for the Low Speed Wind Tunnel at DSTO |
JUN 2004 |
|
| Authors:
Stephen Lam; Adam Blandford; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV
|
| DSTO operates a low speed wind tunnel within the Air Vehicles Division of the Platforms Sciences Laboratory. Airspeeds up to approximately 100 m/s can be produced in the empty test section which is 2.7 m wide by 2.1 m high. Realtime display of acquired test data from the wind tunnel is important for providing feedback to the project manager and test engineer. A software package called DSPFRC was developed for ... |
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| Evaluation and Experimental Validation of Low Costs CFD Based Mathematical Model Describing External Stores Separation |
JUN 2004 |
21 pages |
| Authors:
Wieslaw Buler; Leszek Loroch; Krzysztof Sibilski; Andrzej Zyluk; AIR FORCE INST OF TECHNOLOGY WARSAW (POLAND)
|
| This work consists the concepts and some results of solutions for aircraft external store configuration interference. The main emphasis is placed on practical, cost-effective engineering solution of the complex problem with reasonable computational efficiency allowing the code to run on PC computers. Prediction of external stores separation trajectories is an important task in the aerodynamic design area having the objective to define the operational, release envelopes. To attain this purpose ... |
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| Advances in Modeling and Simulation Capabilities for Predicting Store Trajectories - Past Success and Future Challenges |
JUN 2004 |
15 pages |
| Authors:
A. Cenko; A. Piranian; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD STORE SEPARATION BRANCH
|
| Any time a new aircraft is introduced into service, or an old aircraft undergoes substantial modifications or needs to be certified to carry and employ new stores, the store separation engineer is faced with a decision about how much effort will be required to provide an airworthiness certification for the aircraft and stores. Generally, there are three approaches that have been used: Wind Tunnel Testing, Computational Fluid Dynamics (CFD) analyses ... |
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| Evaluation of Dynamic Lift Coefficients of High Aspect Ratio Rudders and Control Surfaces |
06 MAY 2004 |
74 pages |
| Authors:
Jared R. Patton; NAVAL ACADEMY ANNAPOLIS MD
|
| The goal of this Trident Project was the determination of the maximum dynamic lift coefficient of high aspect ratio control surfaces to reduce the uncertainty in design. The effective design of rudders, diving planes and other control surfaces with high aspect ratios, i.e. a larger depth in proportion to chord length, is hindered by uncertainty in the dynamic coefficient of lift of the control surface as it passes through a ... |
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| Investigation of Combined Low-Angled Jets and Variable Wall Geometry for Hypersonic Aerodynamic Control |
05 MAY 2004 |
84 pages |
| Authors:
Rodney D. Bowersox; Charles L. Karr; Muhammad Sharif; ALABAMA UNIV TUSCALOOSA DEPT OF AEROSPACE ENGINEERING AND MECHANICS
|
| The principal objective of the present research proposal was to investigate, experimentally and numerically, the use of jets to actively control the aerodynamic forces for high-speed flight vehicles. As a test bed, single port injection into a Mach 5.0 crossflow through diamond and circular orifices, at various incidence angles and momentum ratios were examined. To meet the objective, a research program was performed to characterize and control the secondary flow ... |
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| Verification of Simulation Results Using Scale Model Flight Test Trajectories |
MAY 2004 |
66 pages |
| Authors:
Jeff Obermark; ARMY AVIATION AND MISSILE COMMAND REDSTONE ARSENAL AL MISSILE RESEARCH DEVELOPMENT AND ENGINEERING CENTER
|
| The objective of this effort was to compare limited amounts of scale model trajectory data with appropriate full-scale data. The scale model data was scaled up to equivalent full-scale conditions. Two Degree-of-Freedom (2-DOF) trajectories and calculated miss-distances were compared to full-scale data. Likely error sources in the scale test process were identified. Simulation was used to estimate the effects of these errors on the trajectory. Simulation trends were used to ... |
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| Plasma Actuators for Separation Control on Stationary and Oscillating Airfoils |
MAY 2004 |
253 pages |
| Authors:
Martiqua L. Post; T. Corke; NOTRE DAME UNIV IN
|
| Given the importance of separation control associated with retreating blade stall on helicopters, the primary objective of this work was to develop a plasma actuator flow control device for its use in controlling leading-edge separation on stationary and oscillating airfoils. The plasma actuator consists of two copper electrodes separated by a dielectric insulator. When the voltage supplied to the electrodes is sufficiently high, the surrounding air ionizes forms plasma in ... |
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| AVIA: Adaptive Virtual Aerosurface |
30 APR 2004 |
32 pages |
| Authors:
D. Parekh; A. Glezer; M. Allen; T. Crittenden; E. Birdsell; GEORGIA TECH RESEARCH CORP ATLANTA
|
| One can change the effective shape of a surface without any change in its physical moldlines through the transient injection of momentum to control unsteady flow phenomena, such as separation. This research program consists of a system level evaluation of the potential benefits and costs of active flow control as applied to UAVs for separation control, development of innovative actuator concepts, and proof-of-concept experiments showing aerodynamic effectiveness. System-level benefits include ... |
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| Navier-Stokes Predictions of the Individual Components of the Pitch- Damping Coefficient Sum |
APR 2004 |
44 pages |
| Authors:
Paul Weinacht; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| An approach for predicting the two individual aerodynamic damping coefficients that form the pitch-damping coefficient sum is presented. The coefficients are obtained using prescribed or forced motions that independently excite the two different angular rates that are associated with the two damping coefficients. A key feature of the approach is that steady flow fields are produced by the selected motions. Steady flow computational fluid dynamics approaches can be applied, allowing ... |
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| Analytical Calculation of Helicopter Main Rotor Blade Flight Loads in Hover and Forward Flight |
APR 2004 |
24 pages |
| Authors:
Ki C. Kim; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| An aeroelastic analysis was conducted to calculate flight loads on the OH-58D Kiowa Warrior main rotor blade at hover and forward flight conditions. Centrifugal force and flap and chord bending moments were calculated with the University of Maryland Advanced Rotorcraft Code (UMARC) comprehensive helicopter aeroelastic analysis code. The calculated loads were correlated with available flight data for the Bell model 406LM helicopter (model 406T rotor blade) to validate the analytical ... |
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| Effect of the Proposed Closure of NASA's Subsonic Wind Tunnels: An Assessment of Alternatives |
APR 2004 |
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| Authors:
Dennis O. Madl; Terrence A. Trepal; Alexander F. Money; James G. Mitchell; INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA
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| This paper addresses the expected effect of NASA's decision to close the National Full-Scale Aerodynamic Complex (NFAC) and the 12-Foot Pressure Wind Tunnel on the Department of Defense (DoD) and the U.S. aerospace industry. The wind tunnels in the NFAC are the largest and second largest in the world. This paper contains a brief history of the relationship between NASA and the DoD with respect to aeronautical test facilities, including ... |
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| Characteristics of a Cambered Circulation Control Airfoil Having Both Upper and Lower Surface Trailing Edge Slots |
APR 2004 |
85 pages |
| Authors:
Jane Abramson; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| A circulation control (CC) elliptic airfoil section with a thickness- to-chord ratio of 0.17 and 1- percent circular arc camber, was experimentally evaluated to determine its low speed aerodynamic characteristics. The model profile is that of a previously tested single upper surface trailing edge slot airfoil, modified to incorporate an additional blowing slot on the lower surface. The main objective of this initial test was to determine if the control ... |
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| Filtered Rayleigh Scattering Velocimetry for Wind Tunnel Applications |
APR 2004 |
188 pages |
| Authors:
Jim Crafton; Greg Elliott; Campbell Carter; Tom Beutner; Henry Baust; INNOVATIVE SCIENTIFIC SOLUTIONS INC DAYTON OH
|
| Molecular/atomic filter techniques offer the potential of making quantitative and multi-component two-dimensional velocity measurements. Furthermore, they appear well suited to applications in large scale facilities. As such, considerable interest in these techniques has been generated during the past several years. The goals of the current research program were to develop and demonstrate a molecular filtered based velocimetry system (including the hardware and software). The system demonstration was to be carried ... |
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| Transition in Hypersonic Flows Including High-Temperature Gas Effects |
24 MAR 2004 |
5 pages |
| Authors:
Christian Stemmer; UNIVERSITY OF TECH AT DRESDEN (GERMANY)
|
| Hypersonic transition poses a special challenge for direct numerical simulations. Comparable data from Wind-tunnel tests or free-flight testing are not available or not accurate enough for comparison. The wind-tunnel testing does not allow for the exact match to the free-flight conditions at such high Mach-numbers. Flat-plate boundary-layer transition at high Mach-numbers is investigated in this work. A simulation case was chosen where chemical non-equilibrium plays an important role but ionization ... |
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| Instrumentation for Wind Tunnel Transient Growth Studies |
10 MAR 2004 |
13 pages |
| Authors:
Edward B. White; CASE WESTERN RESERVE UNIV CLEVELAND OHDEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Wind tunnel studies on the laminar-to-turbulent transition mechanism known as transient growth require instrumentation suitable for the production of high but controllable levels of freestream turbulence, model surfaces relevant to transition problems of engineering interest, and hotwire instrumentation suitable for measuring disturbances that lead to transition. Ongoing and planned experiments on transient growth at the Case Western Reserve University Wind Tunnel Laboratory required instrumentation in each of these categories to ... |
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| An Investigation of Flow Acceleration and Electromagnetic Absorption Phenomena Induced by Paraelectric and Peristaltic Electrohydrodynamic Effects of the One Atmosphere Uniform Glow Discharge Plasma |
08 MAR 2004 |
25 pages |
| Authors:
TENNESSEE UNIV KNOXVILLE
|
| We took wind tunnel data and were able to demonstrate low speed (below 5 m/sec) flow attachment on a NACA 0015 airfoil using OAUGDP plasma actuators. We were able further to demonstrate that only one actuator was sufficient to produce re-attachment, and that this actuator should be located not at the site of the flow separation bubble, but at the leading edge of the airfoil. The plasma actuators not only ... |
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| Flow Around an Object Projected from a Cavity into a Supersonic Freestream |
MAR 2004 |
90 pages |
| Authors:
Scott T. Bjorge; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The pressure and flow field of a supersonic flow over a cavity, with and without a store, was the focus of this experiment. One cavity geometry (length to depth ratio 3.6) was studied; the freestream Mach number and the placement of the store relative to the cavity floor were varied. The pressure spectra on the cavity floor were markedly different between Mach numbers of 1.8 and 2.9. The Mach 1.8 ... |
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| Fluidic Virtual Aerosurfaces for Flow Control Applications |
MAR 2004 |
74 pages |
| Authors:
Ari Glezer; GEORGIA INST OF TECH ATLANTA SCHOOL OFMECHANICAL ENGINEERING
|
| This research program has focused on a novel approach to the control of the aerodynamic performance of lifting surfaces by fluidic modification of their apparent aerodynamic shape, or virtual aerosurface shaping, This flow control approach emphasizes fluidic modification of the "apparent" aerodynamic shape of the surface with the objective of altering or prescribing the streamwise pressure gradient. Control is typically effected by the interactions of arrays of synthetic jet actuators ... |
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| Experimental Investigation into the Aerodynamic Performance of Both Rigid and Flexible Wing Structured Micro-Air-Vehicles |
MAR 2004 |
174 pages |
| Authors:
Anthony M. DeLuca; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The Air Force Research Lab, Munitions Directorate, Eglin Air Force Base, Florida has designed a man-portable carbon-fiber Micro-Air-Vehicle (MA V) used for on-the-spot surveillance by Special Operations Forces (SOF) for enemy reconnaissance as well as post-strike Battle Damage Assessment (BDA).The main goals of this experiment are: 1) characterize the flow quality of the new AFIT 3' x 3' wind tunnel and 2) determine the aerodynamic performance characteristics of the 24" ... |
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| Magnetogasdynamic Flow Control of a Mach Reflection |
MAR 2004 |
98 pages |
| Authors:
Brian E. Earp; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| Two-dimensional regular and Mach reflections have been studied in the Mach 4.96 dual-solution domain for a 25 and 26 double-fin inlet. The steady-state computational Mach and regular reflections were subjected to magnetogasdynamic forces to determine whether these forces could be used as a possible flow control mechanism. The numerical code employed for this research solved the inviscid Euler equations with added source terms for the ponderomotive force and accompanying energy ... |
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| Optimal Aeroacoustic Shape Design Using the Surrogate Management Framework |
09 FEB 2004 |
25 pages |
| Authors:
Alison L. Marsden; Meng Wang; John E. Dennis Jr; Parviz Moin; RICE UNIV HOUSTON TX DEPT OF COMPUTATIONAL AND APPLIED MATHEMATICS
|
| Shape optimization is applied to time-dependent trailing-edge flow in order to minimize aerodynamic noise. Optimization is performed using the surrogate management framework (SMF), a non-gradient based pattern search method chosen for its efficiency and rigorous convergence properties. Using SMF, design space exploration is performed not with the expensive actual function but with an inexpensive surrogate function. The use of a polling step in the SMF guarantees that the algorithm generates ... |
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| Outside Loop Control in Asymmetrical Trimmed Flight Conditions |
FEB 2004 |
145 pages |
| Authors:
Gary D. Miller; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| Traditionally flight control systems have used linearized equations of motion solved around a single trim point. This thesis proposes a nested-loop controller directly solved from the equations of motion. The control equations were developed as a solution to asymmetrically trimmed flight conditions. A two- loop design was proposed for the controller. The outer loop modeled the aircraft as a point mass and all forces were balanced to find the aircraft ... |
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| Active Flow Control Using MEMS |
FEB 2004 |
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| Authors:
Clyde Warsop; BAE SYSTEMS BRISTOL (UNITED KINGDOM) ADVANCED TECHNOLOGY CENTRE
|
| This lecture presents an overview of the potential for the application of MEMS for the active control of fluid flows. In addition to providing a general overview of the underlying fluid mechanics and status of current research the relevance of this technology application to future military vehicle technologies is highlighted. The lecture identifies the potential benefits of the use of MEMS for controlling flow separation and reducing drag on a ... |
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| UAV Aerial Refueling - Wind Tunnel Results and Comparison with Analytical Predictions |
JAN 2004 |
10 pages |
| Authors:
William B. Blake; Edward G. Dickes; AIR FORCE RESEARCH LAB (AFRL/VACA) WRIGHT-PATTERSON AFB OH CONTROL THEORY OPTIMIZATION BRANCH
|
| Results from a wind tunnel. test of a delta wing UAV behind a KC-135R are presented and compared with predictions from a planar vortex lattice code. Both the predictions and data show wake interference effects on the UAV that vary significantly with relative lateral and vertical position, and weakly with relative longitudinal position. Predicted trends are excellent for all force and moments except for drag, and magnitudes are reasonably well ... |
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| Motor Flow Instabilities - Part 2. Intrinsic Linear Stability of the Flow Induced by Wall Injection |
JAN 2004 |
65 pages |
| Authors:
G. Casalis; F. Vuillot; OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AERONOSPATIALES CEDEX FRANCE SYSTEMS CONTROL/FLIGHT DYNAMICS
|
| Thrust oscillations generally occur in large solid propellant motor during a few seconds of the flight, they exactly correspond to the frequencies of the cavity modes. The excitation of cavity modes has been reproduced in small scale solid propellant motors and also in cold gas facilities. However as extensively exposed by F. Vuillot in the present VKI lecture series, there are different possible causes of this excitation and all of ... |
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| A New Approach to Aeroelastic Response, Stability and Loads of Missiles and Projectiles |
2004 |
43 pages |
| Authors:
Dewey H. Hodges; GEORGIA INST OF TECH ATLANTA SCHOOL OFAEROSPACE ENGINEERING
|
| A current trend in the development of missiles is in the direction of more flexibility, higher maneuverability, and higher speeds, all of which require a higher level of fidelity for calculations of stability, loads, control, and guidance. To address these issues, the present interdisciplinary basic research was conducted involving structural analysis, dynamics, dynamic stability, aeroelastic stability, and trajectory analysis of missiles, rockets, and projectiles. A computer code for the dynamic ... |
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| Expanding a Flutter Envelope Using Data From Accelerating Flight: Application to the F-16 Fighter Aircraft |
2004 |
|
| Authors:
Charles A. Harris; AIR FORCE FLIGHT TEST CENTER EDWARDS AFB CA
|
| Due to the destructive nature of flutter, flutter testing is a mandatory requirement for certification of both civilian and military aircraft. However, along with the complexity of newer aircraft, the time and cost associated with flutter testing has increased dramatically. Considering that many of the test techniques and analysis methods used to perform flutter testing date back to the 1950s and 1960's it may be time to take a fresh ... |
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| Structural Qualification of Unique Aerospace Structures |
2004 |
17 pages |
| Authors:
Gregory E. Sanford; Jeffry S. Welsh; CSA ENGINEERING INC ALBUQUERQUE NM
|
| The Air Force Research laboratory, Space Vehicles Directorate (AFRL/ VS), and CSA Engineering have developed a large scale structural testing facility on Kirtland AFB, NM. This facility is capable of applying static and dynamic loads with up to 18 independent hydraulic actuators. Coupled with the servo-hydraulic load control unit is a fully integrated 256-channel data acquisition system (DAS). Configurable for strain gages, LVDT's, or virtually any other strain gage-based or ... |
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| Energy-Based Design Methodology for Air Vehicle Systems: Aerodynamic Correlation Study |
2004 |
5 pages |
| Authors:
Richard S. Figliola; CLEMSON UNIV SC
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| This fundamental study served to formulate and predict numerically incompressible airfoil and wing performance in terms entropy generation and develop a useful understanding of its role in design. This work is part of a larger effort to define system-level energy-based design across the spectrum of aircraft size and speed. Work was performed at both AFRL and at Clemson with the intent of developing in-house expertise at AFRL. |
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Aerodynamics
