| Flight Attendant Work/Rest Patterns, Alertness, and Performance Assessment: Field Validation of Biomathematical Fatigue Modeling |
Sep 2012 |
20 pages |
| Authors:
Peter G Roma; Steven R Hursh; Andrew M Mead; Thomas E Nesthus; FEDERAL AVIATION ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROSPACE MEDICAL INST
|
 | Fatigue-induced impairments in neurobehavioral performance capacity may compromise safety in 24-hr operational environments, and developing reliable and valid methods of identifying work/rest patterns that produce fatigue and undermine performance is important. The Sleep, Activity, Fatigue, and Task Effectiveness model (SAFTE; Hursh et al., 2004) is among the more mature fatigue models currently used in military, shift-work, and various transportation operations. The SAFTE model was constructed empirically, integrating classical physiological and ... |
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| Predicting Boat-Generated Wave Heights: A Quantitative Analysis through Video Observations of Vessel Wakes |
18 May 2012 |
115 pages |
| Authors:
Sam W Tan; NAVAL ACADEMY ANNAPOLIS MD
|
| In this study, a new method of conducting vessel wake studies using video observations was evaluated. Using a remote web-based camera, vessel traffic along a section of the Severn River in Annapolis, MD, was recorded and subsequently processed using a newly developed vessel tracking tool. This tracking tool brings together computer vision techniques to track transiting vessels and obtain boat parameters usually investigated in vessel wake studies. When matched with ... |
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| Observing the Evolution of Typhoon Wakes |
30 Mar 2012 |
5 pages |
| Authors:
Steven R Jayne; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The objective of our research program was to observe the temporal and spatial evolution of typhoon cold wakes, in particular we directly observed the mixing associated with turbulence generated by the strong air-sea interaction in a typhoon. These observations will be used to make quantifiable assessments of mixed layer models under the extreme conditions of a typhoon. We also observed the restratification of the cold wake from air-sea fluxes to ... |
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| Temporal and Horizontal Variability of SST Cooling in the Wake of a Hurricane |
20 Mar 2012 |
6 pages |
| Authors:
James F Price; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| This problem/phenomenon studied here, hurricane wake warming, can be viewed as a test case for warming the ocean surface generally. The key finding here is that the relevant heat flux is made up of two components: a slowly varying mean and the diurnally-varying heat flux, here represented by the noon maximum. The former determines the trend of surface temperature, and the latter determines the amplitude of the warming by setting ... |
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| Observations of Hydraulic Roughness and Form Drag in the Wake of a Deep Ice Keel in the Arctic Ocean |
Mar 2012 |
101 pages |
| Authors:
Brandon K Schmidt; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Decrease in Arctic Ocean perennial sea-ice has been observed in recent decades. As sea-ice continues to decline, marine traffic will increase and the United States will require a more active military presence in the Arctic. Future Arctic conditions must be forecasted with increased accuracy to allow for proper planning with regard to the nation's changing role in the region. It is the goal of this thesis to contribute to the ... |
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| Collaborative Research: Advanced Excimer Laser Measurements and LES Modeling of Supersonic Combustion |
27 Feb 2012 |
28 pages |
| Authors:
Robert W Pitz; Suresh Menon; VANDERBILT UNIV NASHVILLE TN - DEPT OF MECHANICAL ENGINEERING
|
| Accurate numerical predictions are essential to the design of scramjet combustors, and in order to develop and properly validate these predictions accurate temperature, species concentration, and velocity measurements must be obtained. Large eddy simulation (LES) promises to give improved predictions of turbulent, supersonic combustion relative to CFD RANS models, and therefore, a LES approach employing a subgrid turbulent mixing model was selected to model both reacting and non-reacting flow in ... |
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| Simulations of the DARPA Suboff Submarine Including Self-Propulsion with the E1619 Propeller |
Jan 2012 |
60 pages |
| Authors:
Nathan Chase; IOWA UNIV IOWA CITY
|
| Simulations of the DARPA Suboff submarine and the submarine propeller E1619 using the overset flow solver CFDShip-Iowa V4.5 are presented. The hull was tested in a straight ahead simulation and also in a starboard turn. Propeller open water curves were obtained for two grids for a wide range of advance coefficients covering high to moderately low loads, and results compared with available experimental data. A verification study was performed for ... |
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| Typhoon Impacts and Student Support |
30 Sep 2011 |
8 pages |
| Authors:
Eric A D'Asaro; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| These grants support efforts in the TC10/ITOP (Tropical Cyclone 2010 / Impacts of Typhoons on the Ocean in the Pacific) program. This program, joint between ONR and Taiwanese investigators, studied the ocean response to typhoons in the western Pacific Ocean in 2010. ITOP focused on the following scientific questions: How does the cold wake of a typhoon form and dissipate? Typhoons produce a complex three-dimensional response of the underlying ocean ... |
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| Observing the Evolution of Typhoon Wakes |
30 Sep 2011 |
4 pages |
| Authors:
Steven R Jayne; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The long-term goal of this research is to observe, understand, quantify, and parameterize upper-ocean mixing for use in global ocean modeling. The objective of our research program is to observe the temporal and spatial evolution of typhoon cold wakes. In particular, we directly observed the mixing associated with turbulence generated by the strong air-sea interactions in a typhoon. These observations will be used to make quantifiable assessments of mixed layer ... |
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| A Fast Quasi-Steady Procedure for Estimating the Unsteady Forces and Moments on a Marine Propeller Behind a Hull |
JUN 2011 |
13 pages |
| Authors:
Robert F. Roddy; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| The development and implementation of a semi-empirical method to estimate the unsteady forces and moments on an open marine propeller mounted behind a hull are discussed. The method relies upon a quasi-steady approach that allows the code to rapidly estimate the forces and moments for a wide variety of propellers. Unlike most other quasi-steady methods that use a point velocity or a velocity integrated over a line, this method uses ... |
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| Yip - Development and Application of a High-Speed Three-Dimensional Density Measurement Technique for Aero-Optic Applications |
25 Mar 2011 |
96 pages |
| Authors:
Brian S Thurow; AUBURN UNIV AL DEPT OF AEROSPACE ENGINEERING
|
| A density measurement technique based on the planar laser induced fluorescence (PLIF) of acetone vapor was developed and shown to be practical for 2-D density measurements in a high speed wind transonic wind tunnel. The random uncertainty in density measurements was estimated to be on the order of 8% without pixel binning and as low as 3% with pixel binning, thus showing that acetone PLIF is a viable technique for ... |
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| Two-Way Coupled Atmospher-Ocean Modeling Of The PhilEx Intensive Observational Periods |
MAR 2011 |
12 pages |
| Authors:
Paul W. May; James D. Doyle; Julie D. Pullen; Laura T. David; NAVAL RESEARCH LAB MONTEREY CA MARINE METEOROLOGY DIV
|
| High-resolution coupled atmosphere-ocean simulations of the Philippines show the regional and local nature of atmospheric patterns and ocean response during Intensive Observational Period cruises in January-February 2008 (IOP-08) and February-March 2009 (IOP-09) for the Philippine Straits Dynamics Experiment. Winds were stronger and more variable during IOP-08 because the time period covered was near the peak of the northeast monsoon season. Distinct wind jets between islands and wakes behind islands are ... |
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| Management of Circadian Desynchrony (Jetlag and Shiftlag) in CF Air Operations |
DEC 2010 |
54 pages |
| Authors:
Michel A. Paul; Gary W. Gray; Harris R. Lieberman; Ryan J. Love; James C. Miller; Josephine Arendt; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
|
| In response to operational difficulties resulting from the effects of fatigue (secondary to jetlag and shiftlag) on performance of Air Force personnel, the Air Force funded a 4-year project to optimize CF ability to manipulate circadian rhythms forwards or backwards to counter jetlag and shiftlag. This report presents the highlights of that work and offers recommendation for exploitation of this new capability to sustain operational readiness. The project consisted of ... |
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| ITOP 2010 Field Experiment |
30 SEP 2010 |
8 pages |
| Authors:
Patrick A. Harr; Russell L. Elsberry; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
|
| The long-term goal of this project is to increase understanding of the interaction between the ocean and tropical cyclones over the tropical western North Pacific. Tropical cyclones produce a three-dimensional response of the underlying ocean that includes surface currents, upwelling of the thermocline, and formation of a cold wake. These responses then impact the structure and intensity of the tropical cyclone. Specific objectives are to provide leadership to the ITOP ... |
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| Bubble Clustering in the Ocean and Acoustic Implications |
Nov-2009 |
5 pages |
| Authors:
Thomas C Weber; NEW HAMPSHIRE UNIV DURHAM CENTER FOR COASTAL AND OCEAN MAPPING (CCOM)
|
| This research is intended to further the understanding of how high-frequency acoustic fields interact with bubble clouds in highly dynamic environments (e.g., in ship wakes or near the ocean surface). The results of this type of research can be used to help refine high frequency sonar performance models, to select optimal sonar frequencies, and to refine detection and classification routines. The results of this research can also be used to ... |
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| F-16 Ventral Fin Buffet Alleviation Using Piezoelectric Actuators |
Sep-2009 |
122 pages |
| Authors:
Joseph S Browning; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| Buffet-induced vibrations can have a disastrous impact on aircraft structures. Early attempts at combating buffet vibrations included passive methods such as structural enhancements and leading edge fences. Active methods have shown greater promise, including active airflow control, control surface modulation, and active structural control using piezoelectric actuators. Surface mounted piezoelectric actuators impart directional strain reducing the negative effects associated with harmful vibration. The Block-15 F-16 ventral fin represents an aircraft ... |
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| Capabilities for Magnus Prediction in Subsonic and Transonic Flight |
Dec-2008 |
9 pages |
| Authors:
J DeSpirito; S I Silton; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The Magnus characteristics of three spin-stabilized projectiles were characterized using steady-state RANS and time-accurate RANS/LES computational fluid dynamic simulations. RANS/LES simulations improved the Magnus moment prediction for projectiles with rounded or chamfered bases. No difference was found between the RANS and RANS/LES simulations for the projectile with a sharp-cornered base?either with or without a boattail. The near-body flow field was similar for RANS and RANS/LES simulations; but the RANS/LES simulations ... |
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| DNS and RANS Simulation of Dispersion Downstream of an Obstacle |
Dec-2008 |
9 pages |
| Authors:
Gianluca Iaccarino; Riccardo Rossi; BOLOGNA UNIV (ITALY)
|
| Dispersion in the wake of an obstacle is studied as a step towards the analysis of bio-agent release in urban environments. Available experimental measurements are used to compare in details numerical predictions obtained using Reynolds-Averaged Navier-Stokes (RANS) techniques and Direct Numerical Simulations (DNS). In particular, turbulent scalar fluxes are compared to assess the quality of simple closure based on eddy diffusivity assumptions. The results obtained using different RANS closures show ... |
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| Measurements in Film Cooling Flows with Periodic Wakes |
OCT 2008 |
14 pages |
| Authors:
Kristofer M. Womack; Ralph J. Volino; Michael P. Schultz; NAVAL ACADEMY ANNAPOLIS MD DEPT OF MECHANICAL ENGINEERING
|
| Film cooling flows subject to periodic wakes were studied experimentally. The wakes were generated with a spoked wheel upstream of a flat plate. Cases with a single row of cylindrical film cooling holes inclined at 35 deg to the surface were considered at blowing ratios of 0.25, 0.50, and 1.0 with a steady freestream and with wake Strouhal numbers of 0.15, 0.30, and 0.60. Temperature measurements were made using an ... |
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| Combined Effects of Wakes and Jet Pulsing on Film Cooling |
OCT 2008 |
13 pages |
| Authors:
Kristofer M. Womack; Ralph J. Volino; Michael P. Schultz; NAVAL ACADEMY ANNAPOLIS MD DEPT OF MECHANICAL ENGINEERING
|
| Pulsed film cooling jets subject to periodic wakes were studied experimentally. The wakes were generated with a spoked wheel upstream of a flat plate. Cases with a single row of cylindrical film cooling holes inclined at 35 deg to the surface were considered at blowing ratios B of 0.50 and 1.0 with jet pulsing and wake Strouhal numbers of 0.15, 0.30, and 0.60. Wake timing was varied with respect to ... |
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| Pylon Effects on a Scramjet Cavity Flameholder Flowfield |
01-Sep-2008 |
204 pages |
| Authors:
Andrew B Freeborn; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Cavity flameholders in supersonic combustion ramjet (scramjet) combustors, while effective, fail to take advantage of the full combustor volume. Adding a pylon to the leading edge of a cavity flameholder generates a flowfield increasing mass exchange between the cavity and main combustor flow, increasing the mixing interface between flameholder products and main combustor flow, and exhibiting minimal Reynolds number effects. To demonstrate this modified flowfield driven by supersonic expansion behind ... |
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| Combined Effects of Wakes and Jet Pulsing on Film Cooling |
AUG 2008 |
13 pages |
| Authors:
Kristofer M. Womack; Ralph J. Volino; Michael P. Schultz; NAVAL ACADEMY ANNAPOLIS MD DEPT OF MECHANICAL ENGINEERING
|
| Pulsed film cooling jets subject to periodic wakes were studied experimentally. The wakes were generated with a spoked wheel upstream of a flat plate. Cases with a single row of cylindrical film cooling holes inclined at 35 deg to the surface were considered at blowing ratios B of 0.50 and 1.0 with jet pulsing and wake Strouhal numbers of 0.15, 0.30, and 0.60. Wake timing was varied with respect to ... |
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| Ship Airwake Correlation Analysis for the San Antonio Class Transport Dock Vessel |
21 MAY 2008 |
16 pages |
| Authors:
Jason Geder; Ravi Ramamurti; William C. Sandberg; NAVAL RESEARCH LAB WASHINGTON DC
|
| A space-time correlation function method is applied to the analysis of Large Eddy Simulation (LES) unsteady ship airwake data computed for the LPD 17. Correlation functions are computed for potentially dangerous velocity bursting events visually tracked in space and time in the air vehicle landing zone. It is shown that a correlation function approach is of potential value but the usefulness of the approach is very sensitive to the knowledge, ... |
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| Military Disaster Response: Strategy, Leadership, and Actions- Closing the Gap |
15 MAR 2008 |
35 pages |
| Authors:
Jr Ring Kenneth E.; ARMY WAR COLL CARLISLE BARRACKS PA
|
| The United States Military represents America's most capable organization for massive short-notice response to natural and manmade disasters yet an effective and coordinated military response remains elusive. Primary responsibility for disaster response rests with civilian agencies at the local state and federal level; however they do not possess the military's manpower equipment training and organization necessary to amass the relief effort required for a catastrophic incident. Hurricane Katrina proved that ... |
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| Boat-Wave-Induced Bank Erosion on the Kenai River, Alaska |
01-Mar-2008 |
145 pages |
| Authors:
Stephen T Maynord; David S Biedenham; Craig J Fischenich; Jon E Zufelt; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| The Kenaitze Indian Tribe requested that the U.S. Army Engineer Research and Development Center (ERDC) determine the relative contribution of boat-wake-induced bank erosion to total bank erosion along the Kenai River. The approach used in this study consisted of a delineation of boat wave characteristics along the study reach and a geomorphic and bank stability assessment. This analysis showed that, at specific times of the year and at specific locations, ... |
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| Momentum Exchange Near Ice Keels in the Under Ice Ocean Boundary Layer |
01 MAR 2008 |
51 pages |
| Authors:
John C. Bleidorn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis describes momentum exchange in the under-ice ocean boundary layer near ice keels. Understanding ice-ocean momentum exchange is important for accurate predictive ice modeling. Due to climate change, increased naval presence in the Arctic region is anticipated and ice models will become necessary for tactical and safety reasons. Measurements took place in March 2007 in the Beaufort Sea at the Applied Physics Laboratory Ice Station sponsored by the U.S. ... |
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| Numerical Study of Active Flow Control for a Transitional Highly-Loaded Low-Pressure Turbine |
FEB 2008 |
45 pages |
| Authors:
Donald P. Rizzetta; Miguel R. Visbal; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AERONAUTICAL SCIENCES DIVISION
|
| Active control was simulated numerically for subsonic flow through a highly-loaded low-pressure turbine. At a nominal Reynolds number of 25,000 based upon axial chord and inlet conditions, massive separation occurred on the suction surface of each blade. Vortex generating jets were then used to help mitigate separation, thereby reducing wake losses. Computations were performed using both steady blowing and pulsed mass injections. The numerical method utilized a centered compact finite-difference ... |
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| Trait Anxiety and Salivary Cortisol During Free Living and Military Stress |
Feb-2008 |
9 pages |
| Authors:
Jared P Reis; Marcus K Taylor; Kenneth P Sausen; Eric G Potterat; Genieleach A Padilla; Amanda E Markham; Sean P Drummond; Amanda E Miller; NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
|
| Accumulating evidence suggests that negative affect is associated with elevated cortisol. Limited research has investigated this association in young, highly functioning, and stress-resilient populations. Methods: We examined the relation of trait anxiety with total and diurnal salivary cortisol during free-living conditions and during a stressful military exercise in 26 military men ages 19 -30 yr (M = 21.6, SD = 2.3). Salivary cortisol was assessed at five time points over ... |
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| Vortex-Induced Vibration: Universal Phenomena in Diverse Systems |
OCT 2007 |
14 pages |
| Authors:
Charles H. Williamson; CORNELL UNIV ITHACA NY OFFICE OF SPONSORED PROGRAMS
|
| The long-term goals of the research under this award have been to discover and understand generic phenomena in a whole class of vortex-induced vibration systems. We discover, using novel controlled damping, that the immense scatter in the classical Griffin plot (peak amplitude versus mass-damping) over 3 decades, can now be collapsed beautifully if one renormalises the axes, taking into account the effect of Reynolds number, which was previously not considered. ... |
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| Joint High Speed Sealift (JHSS) Baseline Shaft & Strut (BSS) Model 5653-3: Series 2, Propeller Disk LDV Wake Survey; and Series 3, Stock Propeller Powering and Stern Flap Evaluation Experiments |
SEP 2007 |
121 pages |
| Authors:
Dominic S. Cusanelli; Christopher J. Chesnakas; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| Model 5653-3, scale ratio 34.121, is representative of the Joint High Speed Sealift (JHSS) conventional Baseline Shaft & Strut (BSS) hullform with Gooseneck Bulb (GB). This report documents the Propeller Disk LDV Wake Survey tests (Series 2) and Stock Propeller Powering and Stern Flap Evaluation tests (Series 3. In order to assist in the design of a propeller for the BSS hull, the nominal wakes in the inboard and outboard ... |
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| Sensitivity and Trade-Off Analysis of Wave Making Resistance and Stability of Small Water Plane Area Trimarans |
SEP 2007 |
273 pages |
| Authors:
Brian R. Boudreau; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Recent concept ship designs have called for a vessel with the capability to lift and transport multiple medium displacement combatant boats, approximately 40 to 100 tons, at high speeds over thousands of nautical miles. One such design placed two small water plane area (SWATH) side hulls significantly aft of the center hull transom to facilitate a heavy duty hoist system. This thesis determines the optimal longitudinal and lateral positioning of ... |
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| Fighting Islamic Terrorists With Democracy: A Critique |
21 MAY 2007 |
80 pages |
| Authors:
Jr Stebbins William E.; ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS SCHOOL OF ADVANCED MILITARY STUDIES
|
| The response of U.S. foreign policy to the volatile rise of global jihadism in the wake of the 9/11 attacks has been sweeping and multifaceted. One key pillar of U.S. strategic response has been the active promotion of Western representative democracy in those regions of the Islamic world identified as jihadist centers of incubation (namely: Afghanistan and Iraq). This objective-commitment to establishing representative democracies in Afghanistan and Iraq-has required, and ... |
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| Turbulence and Complex Flow Phenomena in Multi-Stage Axial Turbomachines |
10 MAY 2007 |
35 pages |
| Authors:
Joseph Katz; Charles Meneveau; JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF MECHANICAL ENGINEERING
|
| The objective of this project is to measure the flow within axial turbomachines and use the data to address turbulence modeling issues. Measurements are performed in two-stage transparent machines located in an optically index matched facility, which allows unobstructed 2-D and Stereo PIV measurements. Data provide insight on blade-wake, wake- boundary layer and wake-wake interactions. This report examines and elucidates several phenomena: i. Variations in turbulence within a wake generated ... |
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| Large Eddy Simulation for Heat Transfer Prediction in a Gas Turbine Environment: Development of a High-Order Overset Mesh LES Solver |
30 MAR 2007 |
65 pages |
| Authors:
Sanjiva K. Lele; R. Bhaskaran; Z. Xiong; STANFORD UNIV CA
|
| A thorough investigation of leading edge heat transfer on a model geometry has been performed using Large-eddy simulation (LES). with support from the current and a previous AFOSR grant. The results from the leading edge study are presented as a detailed Appendix in this report. To address the problem of solving the full three-dimensional turbulent flow in a turbine passage. including the effects of free-stream turbulence from the combustor, and ... |
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| Tip Clearance Control Using Plasma Actuators |
MAR 2007 |
73 pages |
| Authors:
Scott C. Morris; Thomas C. Corke; NOTRE DAME UNIV IN DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| This report documents experimental results from a series of experiments using active flow control to improve the performance and efficiency of turbine tip clearance flows. The flow control was based on plasma actuators. Two experimental facilities were used as part of this research project. The first was a low-speed, large-scale turbine cascade using Pak-B turbine blades. The second was a smaller scale, high-speed cascade with low aspect ratio. The active ... |
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| Wake Structure, Loading and Vibration of Cylinders: Effects of Surface Nonuniformities and Unsteady Inflow |
17 JAN 2007 |
7 pages |
| Authors:
Donald Rockwell; LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS
|
| The flow structure from stationary and oscillating cylinders, both with and without surface treatment, has been characterized in steady currents and waves using techniques of high-image-density particle image velocimetry. This quantitative imaging has led to new insight into the quasi-two-dimensional and three-dimensional features of the near-wake, which are intimately related to the loading on the cylinder, for cases where the cylinder is either stationary or elastically mounted. This program has ... |
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| Active Control of Blade Tonals in Underwater Vehicles |
DEC 2006 |
21 pages |
| Authors:
Anuradha M. Annaswamy; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
|
| The goal of this proposal is to achieve stealth through the reduction or alteration of radiated noise that produce blade tonals in underwater vehicles. The use of active control that is judiciously integrated with passive control is proposed to realize which consists of intentional articulation of suitable surfaces or boundary conditions in the vehicle so as to modify the relevant noise characteristics. By modulating additional surfaces, biological organisms appear to ... |
|
| High-Throughput Analysis of Dynamic Gene Expression Associated with Sleep Deprivation and Recovery Sleep in the Mouse Brain |
DEC 2006 |
33 pages |
| Authors:
Ed Lein; ALLEN INST FOR BRAIN SCIENCE SEATTLE WA
|
| Sleep deprivation in mice causes changes in gene expression in discrete brain regions associated with sleep/wake control as well as higher cognitive functions. Laser capture microdissection was used to isolate a set of relevant brain regions, and these samples were amplified to allow genome-wide genetic profiling on DNA microarrays to search for altered gene expression correlated with sleeping, waking, sleep deprivation and recovery sleep following sleep deprivation. Candidate genes from ... |
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| Experimental Investigation of Pitch Control Enhancement to the Flapping Wing Micro Air Vehicle |
DEC 2006 |
135 pages |
| Authors:
Chin C. Kian; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The mechanical pitching characteristic of the NPS flapping-wing Micro Air Vehicle (MAV) developed by Professor Kevin D. Jones are studied experimentally through the use of constant temperature anemometry and force balance techniques. The MAV without the main fixed-wing is placed in a laminar flow field within a low speed wind tunnel with the wake after the flapping wings characterized with a constant temperature anemometer and thrust generation measured by a ... |
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| Hydrodynamic Performance of a Dual-Slotted Circulation Control Wing of Low-Aspect Ratio |
DEC 2006 |
79 pages |
| Authors:
Martin J. Donnelly; J. M. Cutbirth; Ernest O. Rogers; Sturat D. Jessup; Joel T. Park; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| An extensive experimental effort was undertaken to document the performance of a low-aspect ratio hydrofoil with trailing edge blowing across a Coanda surface in a large water tunnel facility. This facility was the William B. Morgan Large Cavitation Channel in Memphis, TN. The hydrofoil model with a taper ratio of 0.76 was mounted through a load balance. A reflection plane provided for an effective aspect ratio of 2. The dual-slot ... |
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| Performance Impacts Due to Wake in Axil-Flow Turbomachinery (Postprint) |
SEP 2006 |
12 pages |
| Authors:
T. J. Praisner; J. P. Clark; T. C. Nash; M. J. Rice; E. A. Grover; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| Here, we demonstrate that the unsteady losses incurred as turbomachinery wakes mix in downstream rows are a function of the velocity ratio across the downstream row as calculated in the frame of reference of wake generation. Analytical and computational results, compared to measurements of wakes mixing under variable free-stream velocity conditions, reveal that wake-loss alteration is primarily a result of an inviscid dilation of the stream tubes that comprise the ... |
|
| Experimental and Analytical Study of the Hydroacoustics of Propellers in Rigid Ducts |
JUL 2006 |
62 pages |
| Authors:
Scott C. Morris; Thomas Mueller; NOTRE DAME UNIV IN DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| This report describes the results of a detailed study of the fluid dynamics and acoustic signature of a rotor operating in a rigid duct. The study focused on the separation of the acoustic source functions and the system response, or transfer function. A new algorithm was developed and quantified to separate these functions from radiated sound measurements. Measurements of the approach flow turbulence and propeller wake turbulence provided insight into ... |
|
| Wind Tunnel Renovation, Flow Verification and Flapping Wing Analysis |
JUN 2006 |
95 pages |
| Authors:
Curtis Hickle; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The Naval Postgraduate School (NPS) Micro-Air Vehicle (MAV) wind tunnel was refurbished in this study. This wind tunnel has a 61 by 38 centimeter test section with a contraction ratio of 6.75, and testing speeds up to 9 meters per second (m/s). The objectives of this work were to create a high quality, customized facility for further MAV study, and to fully characterize the wake of the MAV at a ... |
|
| Brothers or Rivals? Iran and the Shi'a of Iraq |
JUN 2006 |
163 pages |
| Authors:
Robert C. Hunter; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis examines the loyalty of the Shi a of Iraq. While some Sunni Arab leaders have recently accused the Shi a of Iraq of pledging loyalty to Iran, in fact the Iraqi Shi a are loyal to their own nation. The Shi a have developed different identities in Iran and Iraq due to different historical legacies and patterns of conversion. Modern religious-based political activists in the two nations have ... |
|
| Effect of Side Jets in a Supersonic Flow Measured and Calculated on a Flat Plate and a Generic Missile Configuration |
May-2006 |
34 pages |
| Authors:
Anke Kovar; Erich Schulein; GERMAN AEROSPACE CENTER GOTTINGEN (GERMANY)
|
| An investigation on side jets in an M = 5.0 flow was conducted on a flat plate as well as on a generic missile configuration. Surface pressure measurements, oil flow visualisations, force measurements and associated numerical simulations gave insight into the interaction of different jet configurations and their influence on the efficiency of side jet control described by the amplification factor. The analysis of the data especially in the wake ... |
|
| Experimental Analysis of Propeller Interactions With a Flexible Wing Micro-Air-Vehicle |
23 MAR 2006 |
149 pages |
| Authors:
Brian J. Gamble; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| An investigation into the effects of the propeller slipstream on a flexible wing micro-air-vehicle (MAV) was conducted. The Air Force Research Lab, Munitions Directorate designed a man-portable MAV with a 24 in. wingspan and 6 in. root chord to be used for battle damage assessment and reconnaissance. Two wings have been developed for this MAV. One is a rigid carbon-fiber wing and the other consists of flexible parachute material attached ... |
|
| Store Separations From a Supersonic Cone |
MAR 2006 |
109 pages |
| Authors:
Richard J. Simko; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| The purpose of this research was to analyze the environment a store would travel through if ejected from a supersonic cone. This was done using the Beggar Computational Fluid Dynamics (CFD) code from the Air Force SEEK Eagle Office at Eglin Air Force Base, FL. CFD simulations were compared to experimental results from a previous AFIT thesis and conclusions were drawn based on whether or not the current wind tunnel ... |
|
| Particle Image Velocimetry (PIV) Measurements in the Wake of a Cascade of Compressor Blades at Stall |
MAR 2006 |
98 pages |
| Authors:
Jr Quesenbury Robert C.; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The flow around second generation controlled-diffusion compressor blades in cascade at stall was examined through the use of a Particle Image Velocimeter (PIV). This examination was conducted from the trailing edge of the blade well into the wake region. Flow visualization techniques were used to observe and record the behavior of the region of flow separation. The PIV data showed that the separated regions continued to grow up to approximately ... |
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| Wind Tunnel Study of Interference Effects Relating to Aft Supersonic Ejection of a Store |
DEC 2005 |
118 pages |
| Authors:
Timothy P. Jung; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
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| An investigation into the issues surrounding the release of a store into a supersonic wake was conducted. A 10-degree half-angle cone was used to model the carrier vehicle as well as the store. The store was 42% than the vehicle. The experiments were conducted at a freestream Mach number of 2.93 and at zero degrees angle of attack. This study analyzed the effects of a support or strut mounted under ... |
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| Large Eddy Simulation of Bubbly Ship Wakes |
28 SEP 2005 |
166 pages |
| Authors:
Ismail B. Celik; Ibrahim Yavuz; Andrei Smirnov; WEST VIRGINIA UNIV MORGANTOWN DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| The presence of air bubbles in ship wakes and their dynamic interaction with the turbulent vortical flows create security problems by modifying the hydro-acoustic properties of ship navigation. This study concerns understanding and controlling the mechanisms which may lead to selective concentration of bubbles to form clusters or clouds and to predict their size distribution and motion. Numerical simulations were conducted using the Large Eddy Simulation (LES) technique in conjunction ... |
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Reports by Keyword(s)
WAKE
