3
3.0
texts
eye 3
favorite 0
comment 0
vi, 102, 43 pages : 30 cm
Topic: Wind tunnel walls
382
382
Jul 12, 2010
07/10
by
Card, M. F.; Mccomb, H. G., Jr.; Peebles, S. W
texts
eye 382
favorite 0
comment 0
A simple method of sizing a vibration absorber for a large, cantilevered flexible mast is presented. The method is based on Den Hartog's vibration absorber theory for two-degree-of-freedom systems. Generalized design curves are presented as well as specific numerical results for a candidate space experiment in which a long flexible antenna mast is attached to the shuttle orbiter and dynamically excited by orbiter accelerations. Results indicate that for large flexible masts, the mass of the...
Topics: AIR FLOW, AIRFOILS, WIND TUNNEL WALLS, AERODYNAMICS, PLENUM CHAMBERS, WIND TUNNEL APPARATUS
491
491
Jun 21, 2010
06/10
by
Giacaglia, G. E. O.; Hebb, K.; Lundquist, C. A.; Mair, S. G
texts
eye 491
favorite 0
comment 0
Possible geopotential improvement from satellite altimetry
Topics: AIR FLOW, WAVE GENERATION, WIND TUNNEL APPARATUS, ACTUATORS, VANES, WIND TUNNEL WALLS
723
723
Jul 23, 2010
07/10
by
Craver, W. Lionel, Jr
texts
eye 723
favorite 0
comment 0
The goals for this research were revised and clarified. The goals are restated along with an evaluation of the accomplishment of the goal. All of the cases of the truncated-cone beams that were originally proposed to be solved were solved. A summary of these solutions is presented. Some cases of beams with unequal tapers were solved and are discussed.
Topics: INTERFERENCE, WALL FLOW, WIND TUNNEL TESTS, WIND TUNNEL WALLS, ADAPTIVE CONTROL, LIFT AUGMENTATION,...
231
231
Jun 2, 2011
06/11
by
Maluf, David A.; Tran, Peter B
texts
eye 231
favorite 0
comment 0
Object-Relational database management system is an integrated hybrid cooperative approach to combine the best practices of both the relational model utilizing SQL queries and the object-oriented, semantic paradigm for supporting complex data creation. In this paper, a highly scalable, information on demand database framework, called NETMARK, is introduced. NETMARK takes advantages of the Oracle 8i object-relational database using physical addresses data types for very efficient keyword search...
Topics: PRESSURE MEASUREMENT, WALL PRESSURE, SUBSONIC WIND TUNNELS, WIND TUNNEL WALLS, COMPUTER PROGRAMS,...
257
257
Jul 6, 2010
07/10
by
DROEGE, K
texts
eye 257
favorite 0
comment 0
APPLICATIONS OF TELEOPERATOR MACHINES (REMOTE MANIPULATORS) AND ROBOTS IN VARIOUS AREAS OF TECHNOLOGY ARE DESCRIBED. THE SYNTELMANN TELEOPERATOR IS DISCUSSED IN DETAIL.
Topics: PRESSURE DISTRIBUTION, TRANSONIC WIND TUNNELS, TWO DIMENSIONAL FLOW, WIND TUNNEL WALLS, AERODYNAMIC...
A flow generation section for a wind tunnel test facility is described which provides a uniform flow for the wind tunnel test section over a range of different flow velocities. The throat of the flow generation section includes a pair of opposed boundary walls which are porous to the flowing medium in order to provide an increase of velocity by expansion. A plenum chamber is associated with the exterior side of each of such porous walls to separate the same from ambient pressure. A suction...
Topics: NASA Technical Reports Server (NTRS), FLOW VELOCITY, UNIFORM FLOW, WIND TUNNELS, POROUS WALLS, WIND...
Analytical solutions for the three dimensional inhomogeneous wave equation with flow in a hardwall rectangular wind tunnel and in the free field are presented for a stationary monopole noise source. Dipole noise sources are calculated by combining two monopoles 180 deg out of phase. Numerical calculations for the modal content, spectral response and directivity for both monopole and dipole sources are presented. In addition, the effect of tunnel alterations, such as the addition of a mounting...
Topics: NASA Technical Reports Server (NTRS), REVERBERATION, WAVE EQUATIONS, WIND TUNNEL TESTS, WIND TUNNEL...
1,240
1.2K
Jul 12, 2010
07/10
by
Jones, K. L.; Henshaw, M.; Mcmenomy, C.; Robles, A.; Scribner, P. C.; Wall, S. D.; Wilson, J. W
texts
eye 1,240
favorite 0
comment 0
All images returned by Viking Lander 1 during the extended and continuation automatic phases of the Viking Mission are presented. Listings of supplemental information which describe the conditions under which the images were acquired are included together with skyline drawings which show where the images are positioned in the field of view of the cameras. Subsets of the images are listed in a variety of sequences to aid in locating images of interest. The format and organization of the digital...
Topics: AERODYNAMIC CHARACTERISTICS, WIND TUNNEL WALLS, AIRFOILS, PRESSURE DISTRIBUTION, WALL FLOW, WIND...
A unique opportunity has arisen to test one and the same airfoil model of CAST-7 section in two wind tunnels having adaptive walled test sections. The tunnels are very similar in terms of size and the available range of test conditions, but differ principally in their wall setting algorithms. Detailed data from the tests of the model in the Southampton tunnel, are included with comparisons between various sources of data indicating that both adaptive walled test sections provide low...
Topics: NASA Technical Reports Server (NTRS), AIRFOILS, TRANSONIC WIND TUNNELS, WIND TUNNEL TESTS, WIND...
1,635
1.6K
Jul 11, 2010
07/10
by
NON
texts
eye 1,635
favorite 0
comment 0
The proceedings of a conference on electric storage batteries are presented. The subjects discussed include the following: (1) a low cost/standardization program, (2) test and flight experience, (3) materials and cell components, and (4) new developments in the nickel/hydrogen system. The application of selected batteries in specific space vehicles is examined.
Topics: BOUNDARY LAYER TRANSITION, LAMINAR BOUNDARY LAYER, TURBULENT BOUNDARY LAYER, WIND TUNNEL WALLS,...
Adaptive wall wind tunnel research is summarized. Small scale two and three dimensional wind tunnel experiments and numerical experiments with a three dimensional adaptive wall simulator are included. A NACA 0012 airfoil was tested in a 25 by 13 cm slotted wall test section. Airflow through the test section walls was controlled by adjusting the pressures in segmented plenums. Interference free conditions were successfully attained in subsonic and transonic flows. For the three dimensional...
Topics: NASA Technical Reports Server (NTRS), AIR FLOW, AIRFOILS, WIND TUNNEL WALLS, AERODYNAMICS, PLENUM...
1,366
1.4K
Jul 23, 2010
07/10
by
Thompson, Kevin W
texts
eye 1,366
favorite 0
comment 0
The lecture notes cover the basic principles of computational fluid dynamics (CFD). They are oriented more toward practical applications than theory, and are intended to serve as a unified source for basic material in the CFD field as well as an introduction to more specialized topics in artificial viscosity and boundary conditions. Each chapter in the test is associated with a videotaped lecture. The basic properties of conservation laws, wave equations, and shock waves are described. The...
Topics: BLOCKING, FLOW DISTRIBUTION, FREE FLOW, SIGNATURE ANALYSIS, TWO DIMENSIONAL FLOW, WALL PRESSURE,...
209
209
Jul 12, 2010
07/10
by
Brown, J. R
texts
eye 209
favorite 0
comment 0
The propulsion system requirements of orbit transfer vehicles (OTV). A baseline expander cycle engine which will meet those requirements was defined. The principal characteristics of a baseline engine and some options which are available to accommodate OTV system optimization studies was discussed. Engine program issues which are dependent on the mission scenario and the vehicle system configuration are shown. The rationale for a new cryogenic OTV engine is summarized.
Topics: DRAG REDUCTION, VELOCITY DISTRIBUTION, PRESSURE GRADIENTS, RELAXATION (MECHANICS), TURBULENT...
A fan-in-wing model with a 1.07-meter span was tested in seven different test sections with cross-sectional areas ranging from 2.2 sq meters to 265 sq meters. The data from the different test sections are compared both with and without correction for wall interference. The results demonstrate that extreme care must be used in interpreting uncorrected VTOL data since the wall interference may be so large as to invalidate even trends in the data. The wall interference is particularly large at the...
Topics: NASA Technical Reports Server (NTRS), FAN IN WING AIRCRAFT, VERTICAL TAKEOFF AIRCRAFT, WIND TUNNEL...
455
455
Sep 20, 2010
09/10
by
Jordan, P.; Blaes, V.; Roszman, L.; Cooley, J
texts
eye 455
favorite 0
comment 0
An investigation of the effect of mean local node-crossing time on the evolution of Sun-synchronous orbits was undertaken during Phase-A orbit analysis for the National Oceanic and Atmospheric Administration (NOAA) O,P,Q environmental spacecraft. That analysis added to the growing body of evidence that individual Sun-synchronous missions, at differing node-crossing times, experience nodal drift rates that can differ in both magnitude and direction. A Sun-synchronous orbit is obtained by means...
Topics: AERODYNAMIC INTERFERENCE, FREE FLOW, MACH NUMBER, TABLES (DATA), FLOW DISTRIBUTION, POROUS WALLS,...
A prototype dual-axis electrolytic tilt sensor package for angular position measurements was built and evaluated in a laboratory environment. The objective was to investigate the use of this package for making wind tunnel wall attitude measurements for the National Transonic Facility (NTF) at NASA Langley Research Center (LaRC). The instrumentation may replace an existing, more costly, and less rugged servo accelerometer package (angle-of-attack package) currently in use. The dual-axis...
Topics: NASA Technical Reports Server (NTRS), ATTITUDE (INCLINATION), ATTITUDE INDICATORS, TILTMETERS, WIND...
A problem associated with the wind tunnel testing of very slow flying aircraft is the correction of observed pitching moments to free air conditions. The most significant effects of such corrections are to be found at moderate downwash angles typical of the landing approach. The wind tunnel walls induce interference velocities at the tail different from those induced at the wing, and these induced velocities also alter the trajectory of the trailing vortex system. The relocated vortex system...
Topics: NASA Technical Reports Server (NTRS), INTERFERENCE, VELOCITY MEASUREMENT, WIND TUNNEL WALLS, WINGS,...
Corrections for wind tunnel wall interferences are applied successfully to high lift models when the model to tunnel size ratio is small. The accuracy of the corrections becomes poorer when larger models are tested. An alternate method of testing was developed in which flow through the porous walls of the tunnel was actively controlled so as to approximate free air conditions in the neighborhood of the model during the test. The amount and distribution of the controlled flow through the walls...
Topics: NASA Technical Reports Server (NTRS), INTERFERENCE LIFT, WALL FLOW, WIND TUNNEL WALLS, FLOW...
A study has been made of possible ways to improve the performance of the Langley Research Center's Transonic Dynamics Tunnel (TDT). The major effort was directed toward obtaining increased dynamic pressure in the Mach number range from 0.8 to 1.2, but methods to increase Mach number capability were also considered. Methods studied for increasing dynamic pressure capability were higher total pressure, auxiliary suction, reducing circuit losses, reduced test medium temperature, smaller test...
Topics: NASA Technical Reports Server (NTRS), AIR FLOW, PRESSURE DISTRIBUTION, TEST FACILITIES, TRANSONIC...
3,358
3.4K
Jul 25, 2010
07/10
by
NON
texts
eye 3,358
favorite 0
comment 0
This bibliography lists 454 reports, articles, and other documents introduced into the NASA scientific and technical information system in April, 1989. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics.
Topics: ANECHOIC CHAMBERS, PRESSURE DISTRIBUTION, WIND TUNNEL TESTS, NOISE MEASUREMENT, SOUND PROPAGATION,...
184
184
Jul 12, 2010
07/10
by
NON
texts
eye 184
favorite 0
comment 0
An airfoil which has particular application to the blade or blades of rotor aircraft and aircraft propellers is presented. The airfoil thickness distribution, camber and leading edge radius are shaped to locate the airfoil crest at a more aft position along the chord, and to increase the freestream Mach number at which sonic flow is attained at the airfoil crest. The reduced slope of the airfoil causes a reduction in velocity at the airfoil crest at lift coefficients from zero to the maximum...
Topics: COMPUTATIONAL FLUID DYNAMICS, POTENTIAL FLOW, CRYOGENIC WIND TUNNELS, FLOW DISTRIBUTION, PRESSURE...
968
968
May 29, 2011
05/11
by
Laubacher, Brian A
texts
eye 968
favorite 0
comment 0
Traditionally, Solid Rocket Motor (SRM) internal ballistic performance has been analyzed and predicted with either zero-dimensional (volume filling) codes or one-dimensional ballistics codes. One dimensional simulation of SRM performance is only necessary for ignition modeling, or for motors that have large length to port diameter ratios which exhibit an axial ''pressure drop'' during the early burn times. This type of prediction works quite well for many types of motors, however, when motor...
Topics: AERODYNAMIC INTERFERENCE, DATA PROCESSING EQUIPMENT, COMPUTER PROGRAMS, WIND TUNNEL CALIBRATION,...
255
255
May 27, 2011
05/11
by
Roberts, Leonar
texts
eye 255
favorite 0
comment 0
A simplified analysis is made of ablation cooling near the stagnation point of a two-dimensional or axisymmetric body which occurs as the body vaporizes directly from the solid state. The automatic shielding mechanism Is discussed and the important thermal properties required by a good ablation material are given. The results of the analysis are given in terms of dimensionless parameters.
Topics: WIND TUNNELS, WEIGHT INDICATORS, WIND TUNNEL STABILITY TESTS, WIND TUNNEL CALIBRATION, SCALE...
456
456
Sep 20, 2010
09/10
by
NON
texts
eye 456
favorite 0
comment 0
The US Government's evaluation of the McDonnell Douglas Astronautics Company (MDAC) Tug concept selection data and recommendations presented in July 1973 resulted in a directive to conduct further in-depth analysis and to provide the data and conclusions for three selected Cryogenic Tug program options. The material presented in this MDAC Tug program study is completely responsive to the negotiated statement of work and subsequent direction. The study results provide a comprehensive data base...
Topics: AERODYNAMIC INTERFERENCE, SUBSONIC SPEED, WIND TUNNEL WALLS, AIRFOILS, CORRECTION, HIGH REYNOLDS...
An inflatable seal acts as a pressure-tight zipper to provide traversing capability for instrumentation rakes and probes. A specially designed probe segment with a teardrop cross-section in the vicinity of the inflatable seal minimizes leakage at the interface. The probe is able to travel through a lengthwise slot in a pressure vessel or wind tunnel section, while still maintaining pressure integrity. The design uses two commercially available inflatable seals, opposing each other, to cover the...
Topics: NASA Technical Reports Server (NTRS), INFLATABLE STRUCTURES, LEAKAGE, MEASURING INSTRUMENTS,...
A study was made of the upwash interference caused by the wind tunnel walls at a Mach number of 0.20. The wind tunnel has slotted horizontal walls and solid vertical walls and the wind tunnel model is a wing-fuselage combination typical of a short take-off and landing (STOL) transport. Measurements were made of the model forces and angle of attack. The experimental results are compared to theoretical solutions for the upwash interference. This comparison enabled an indirect determination of one...
Topics: NASA Technical Reports Server (NTRS), INTERFERENCE LIFT, SHORT TAKEOFF AIRCRAFT, SLOTTED WIND...
An analytical procedure is discussed for designing wall shapes for streamlined, nonporous, two-dimensional, transonic wind tunnels. It is based upon currently available 2-D inviscid transonic and boundary layer analysis computer programs. Predicted wall shapes are compared with experimental data obtained from the NASA Langley 6 by 19 inch Transonic Tunnel where the slotted walls were replaced by flexible nonporous walls. Comparisons are presented for the empty tunnel operating at a Mach number...
Topics: NASA Technical Reports Server (NTRS), STRUCTURAL DESIGN, TRANSONIC WIND TUNNELS, WIND TUNNEL WALLS,...
The first documented wind tunnel employing a flexible walled test section for the purpose of eliminating wall interference was constructed in England by the National Physical Laboratory (NPL) during the late 1930's. The tunnel was transonic and designed for two-dimensional testing. In an attempt to eliminate the top and bottom wall interference effects on the model NPL developed a strategy to adjust two flexible walls to streamlined shapes. This report covers an evaluation of the NPL wall...
Topics: NASA Technical Reports Server (NTRS), ADAPTIVE CONTROL, HISTORIES, STREAMLINING, TRANSONIC WIND...
The turbulent boundary layer on the wall of a 9 by 7 foot wind tunnel was measured with 12 different transducers at Mach numbers of 1.6, 2.0, and 2.5. The results indicated that the wall surface-pressure-fluctuation field was more homogeneous at a Mach number of 2.5 than at Mach numbers of 1.6 or 2.0. A comparison of power-spectral-density data at Mach 2.5 with a summary of similar data (Mach 0.1 to 3.45) showed good agreement. The measurement uncertainty was greatest when frequencies were low...
Topics: NASA Technical Reports Server (NTRS), PRESSURE PULSES, SUPERSONIC BOUNDARY LAYERS, TRANSDUCERS,...
An apparatus is described for reducing the background noise produced by the porous walls of the test section of a wind tunnel. A finely meshed screen member is placed over the perforations in the test section walls. The mesh wire screen attached to the interior wall provides a smoother surface for the air stream to flow against reducing the vorticies produced by the edges of the perforations in the test section walls.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC NOISE, NOISE REDUCTION, WIND TUNNELS, MESH,...
It is desirable to achieve low frequency sound absorption in the tests section of the NASA Ames 80X120-ft wind tunnel. However, it is difficult to obtain information regarding sound absorption characteristics of potential treatments because of the restrictions placed on the dimensions of the test chambers. In the present case measurements were made in a large enclosure for aircraft ground run-up tests. The normal impedance of the acoustic treatment was measured using two microphones located...
Topics: NASA Technical Reports Server (NTRS), DAMPING, LININGS, SOUND TRANSMISSION, WIND TUNNEL WALLS,...
A program called FLEXWAL for calculating wall modifications for solid, adaptive-wall wind tunnels is presented. The method used is the iterative technique of NASA TP-2081 and is applicable to subsonic and transonic test conditions. The program usage, program listing, and a sample case are given.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC INTERFERENCE, COMPUTER PROGRAMS, TWO DIMENSIONAL...
In wind tunnel tests, the problems arise of determining the wall pressure distribution, calculating the wall contour, and controlling adjustment of the walls. This report shows how these problems have been solved for the high speed wind tunnel of the Technical University of Berlin.
Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, COMPUTER PROGRAMS, FLEXIBILITY, SERVOCONTROL,...
890
890
Jul 12, 2010
07/10
by
Ferrill, J
texts
eye 890
favorite 0
comment 0
An interview model which facilitates communications between technical and non-technical personnel was developed. It outlines the elements of understanding technical material. Several communication problems were examined and included: how technical writers view the writing process; and whether persons with technical backgrounds view the writing process differently from those with non-technical backgrounds.
Topics: AERODYNAMIC CHARACTERISTICS, TRANSONIC WIND TUNNELS, WIND TUNNEL TESTS, AIRFOILS, FLEXIBLE BODIES,...
In an effort to validate computational fluid dynamics procedures for calculating flows around circulation control airfoils, the commercial flow solver FLUENT was utilized to study the flow around a general aviation circulation control airfoil. The results were compared to experimental and computational fluid dynamics results conducted at the NASA Langley Research Center. The current effort was conducted in three stages: 1. A comparison of the results for free-air conditions to those from...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, CIRCULATION CONTROL AIRFOILS,...
A 2-D boundary layer computer code developed to process data for an arbitrary number of streamlines is presented. Provisions are included for the computer code to determine either mass transfer rates necessary for an effective boundary layer displacement of zero thickness or the effective displacement thickness for a specified mass transfer-rate distribution. The computer code was developed to be compatible with other computer codes which are being modified and/or developed at the NASA-Langley...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, LININGS, TRANSONIC FLOW, WIND TUNNEL...
A two dimensional test section in a low speed wind tunnel capable of producing flow conditions free from wall interference is presented. Flexible top and bottom walls, and rigid sidewalls from which models were mounted spanning the tunnel are shown. All walls were unperforated, and the flexible walls were positioned by screw jacks. To eliminate wall interference, the wind tunnel itself supplied the information required in the streamlining process, when run with the model present. Measurements...
Topics: NASA Technical Reports Server (NTRS), LOW SPEED WIND TUNNELS, STREAMLINING, WIND TUNNEL WALLS,...
Aerodynamic tests in wind tunnels are jeopardized by the lateral limitations of the throat. This influence expands with increasing size of the model in proportion to the cross-section of the throat. Wall interference of this type can be avoided by giving the wall the form of a stream surface that would be identical to the one observed during free flight. To solve this problem, flexible walls that can adapt to every contour of surface flow are needed.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, THROATS, WIND TUNNEL APPARATUS,...
The original flexible top and bottom walls of the Transonic Self-Streamlining Wind Tunnel (TSWT), at the University of Southampton, have been replaced with new walls featuring a larger number of static pressure tappings and detailed mechanical improvements. This report describes the streamling method, results, and conclusions of a series of tests aimed at defining sets of aerodynamically straight wall contours for the new flexible walls. This procedure is a necessary prelude to model testing....
Topics: NASA Technical Reports Server (NTRS), ADAPTIVE CONTROL, FLEXIBILITY, STREAMLINING, TRANSONIC WIND...
Further flexible wall technique validation in two dimensional testing was carried out with the transonic self streamlining wind tunnel (TSWT) using a cambered NPL 9510 section.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CONFIGURATIONS, CAMBERED WINGS, TWO DIMENSIONAL...
Flow characteristics in the low speed Wright Brothers Wind Tunnel were studied. Calculations to check the precision of the tunnel were conducted. A program for generating computational grids around an airfoil was developed and compared with the wind tunnel model. Low Reynolds number flow phenomenon of periodic vortex shedding in a wake were also studied by applying a hot-wire anomemeter.
Topics: NASA Technical Reports Server (NTRS), AIRFOILS, COMPUTATIONAL GRIDS, VORTEX SHEDDING, WIND TUNNEL...
178
178
May 22, 2011
05/11
by
NON
texts
eye 178
favorite 0
comment 0
A method and apparatus for determining the mass density of a moving filament is provided. The method includes the steps of providing a filament across two supports, tensioning the filament, inducing a vibration into the filament segment between the supports, reinforcing the vibration using an amplified feedback signal, detecting the vibrational frequency data, processing the data using a fast-fourier transform analysis, and then displaying the frequency. The use of the feedback signal results...
Topics: AERODYNAMIC INTERFERENCE, ANGULAR RESOLUTION, NOISE INTENSITY, TURBOFANS, WIND TUNNEL WALLS,...
This bibliography, with abstracts, consists of 257 citations arranged in chronological order. Selection of the citations was made for their value to researchers working to solve problems associated with reducing wall interference by the design, development, and operation of adaptive wall test sections. Author, source, and subject indexes are included.
Topics: NASA Technical Reports Server (NTRS), ADAPTIVE CONTROL, AERODYNAMIC INTERFERENCE, WALL FLOW, WIND...
Experimental evaluations of the acoustical characteristics and source sound power and directionality measurement capabilities of the NASA Lewis 9 x 15 foot low speed wind tunnel in the untreated or hardwall configuration were performed. The results indicate that source sound power estimates can be made using only settling chamber sound pressure measurements. The accuracy of these estimates, expressed as one standard deviation, can be improved from + or - 4 db to + or - 1 db if sound pressure...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC MEASUREMENT, LOW SPEED WIND TUNNELS, MICROPHONES,...
Guidelines are presented for use of the computer program STIPPAN to simulate the subsonic flow in a slotted wind tunnel test section with a known model disturbance. Input data requirements are defined in detail and other aspects of the program usage are discussed in more general terms. The program is written for use in a CDC CYBER 200 class vector processing system.
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, SLOTTED WIND TUNNELS, SUBSONIC FLOW, WIND...
502
502
Jul 23, 2010
07/10
by
Chamis, Christos C.; Murthy, Pappu L. N
texts
eye 502
favorite 1
comment 0
Step-by-step procedures are described which can be used for the preliminary design of fiber composite box beams subjected to combined loadings. These procedures include a collection of approximate closed-form equations so that all the required calculations can be performed using pocket calculators. Included is an illustrated example of a tapered cantilever box beam subjected to combined loads. The box beam is designed to satisfy strength, displacement, buckling, and frequency requirements.
Topics: AIRFOILS, CROSS FLOW, FREE FLOW, SHEAR FLOW, STREAMLINING, BOUNDARY CONDITIONS, FLOW DISTRIBUTION,...
190
190
May 29, 2011
05/11
by
Rossano, G. S.; Russell, R. W.; Lynch, D. K.; Tessensohn, T. K.; Warren, D.; Jenniskens, P
texts
eye 190
favorite 0
comment 0
We report broadband 3-5.5 micrometer detections of two Leonid meteors observed during the 1998 Leonid Multi-Instrument Aircraft Campaign. Each meteor was detected at only one position along their trajectory just prior to the point of maximum light emission. We describe the particular aspects of the Aerospace Corp. Mid-wave Infra-Red Imaging Spectrograph (MIRIS) developed for the observation of short duration transient events that impact its ability to detect Leonid meteors. This instrument had...
Topics: COMPUTATIONAL FLUID DYNAMICS, FLOW DISTRIBUTION, PRESSURE DISTRIBUTION, AERODYNAMIC CONFIGURATIONS,...
A transonic Wall-Interference Assessment/Correction (WIAC) procedure has been developed and verified for the 8- by 24-inch airfoil test section of the Langley 0.3-m Transonic Cryogenic Tunnel. This report is a user's manual for the correction procedure. It includes a listing of the computer procedure file as well as input for and results from a step-by-step sample case.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC INTERFERENCE, AIRFOILS, USER MANUALS (COMPUTER...
Acoustical characteristics and source directionality measurement capabilities of the wind tunnel in the softwall configuration were evaluated, using aerodynamically clean microphone supports. The radius of measurement was limited by the size of the test section, instead of the 3.0 foot (1 m) limitation of the hardwall test section. The wind-on noise level in the test section was reduced 10 dB. Reflections from the microphone support boom, after absorptive covering, induced measurement errors in...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC MEASUREMENT, ACOUSTIC PROPERTIES, LOW SPEED WIND...
