Download or read book Wind Tunnel Investigation of the Effects of Surface Porosity and Vertical Tail Placement on Slender Wing Vortex Flow Aerodynamics at Supersonic Speeds written by Gary E. Erickson and published by BiblioGov. This book was released on 2013-07 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wind tunnel experiment was conducted in the NASA Langley Research Center (LaRC) Unitary Plan Wind Tunnel (UPWT) to determine the effects of passive surface porosity and vertical tail placement on vortex flow development and interactions about a general research fighter configuration at supersonic speeds. Optical flow measurement and flow visualization techniques were used that featured pressure sensitive paint (PSP), laser vapor screen (LVS), and schlieren, These techniques were combined with conventional electronically-scanned pressure (ESP) and six-component force and moment measurements to quantify and to visualize the effects of flow-through porosity applied to a wing leading edge extension (LEX) and the placement of centerline and twin vertical tails on the vortex-dominated flow field of a 65 cropped delta wing model. Test results were obtained at free-stream Mach numbers of 1.6, 1.8, and 2.1 and a Reynolds number per foot of 2.0 million. LEX porosity promoted a wing vortex-dominated flow field as a result of a diffusion and weakening of the LEX vortex. The redistribution of the vortex-induced suction pressures contributed to large nose-down pitching moment increments but did not significantly affect the vortex-induced lift. The trends associated with LEX porosity were unaffected by vertical tail placement. The centerline tail configuration generally provided more stable rolling moments and yawing moments compared to the twin wing-mounted vertical tails. The strength of a complex system of shock waves between the twin tails was reduced by LEX porosity.

Download or read book Wind Tunnel Investigation of the Interaction and Breakdown Characteristics of Slender wing Vortices at Subsonic Transonic and Supersonic Speeds written by Gary E. Erickson and published by . This book was released on 1991 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Tunnel Investigation of the Interaction and Breakdown Characteristics of Slender Wing Vortices at Subsonic Transonic and Supersonic Speeds written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-04 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vortex dominated aerodynamic characteristics of a generic 65 degree cropped delta wing model were studied in a wind tunnel at subsonic through supersonic speeds. The lee-side flow fields over the wing-alone configuration and the wing with leading edge extension (LEX) added were observed at M (infinity) equals 0.40 to 1.60 using a laser vapor screen technique. These results were correlated with surface streamline patterns, upper surface static pressure distributions, and six-component forces and moments. The wing-alone exhibited vortex breakdown and asymmetry of the breakdown location at the subsonic and transonic speeds. An earlier onset of vortex breakdown over the wing occurred at transonic speeds due to the interaction of the leading edge vortex with the normal shock wave. The development of a shock wave between the vortex and wing surface caused an early separation of the secondary boundary layer. With the LEX installed, wing vortex breakdown asymmetry did not occur up to the maximum angle of attack in the present test of 24 degrees. The favorable interaction of the LEX vortex with the wing flow field reduced the effects of shock waves on the wing primary and secondary vortical flows. The direct interaction of the wing and LEX vortex cores diminished with increasing Mach number. The maximum attainable vortex-induced pressure signatures were constrained by the vacuum pressure limit at the transonic and supersonic speeds. Erickson, Gary E. Langley Research Center NASA-TP-3114, L-16803, NAS 1.60:3114 RTOP 505-68-71-03...

Download or read book Wind Tunnel Investigation of Vortex Flows on F a 18 Configuration at Subsonic Through Transonic Speed written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wind tunnel experiment was conducted in the David Taylor Research Center 7- by 10-Foot Transonic Tunnel of the wing leading-edge extension (LEX) and forebody vortex flows at subsonic and transonic speeds about a 0.06-scale model of the F/A-18. The primary goal was to improve the understanding and control of the vortical flows, including the phenomena of vortex breakdown and vortex interactions with the vertical tails. Laser vapor screen flow visualizations, LEX, and forebody surface static pressures, and six-component forces and moments were obtained at angles of attack of 10 to 50 degrees, free-stream Mach numbers of 0.20 to 0.90, and Reynolds numbers based on the wing mean aerodynamic chord of 0.96 x 10(exp 6) to 1.75 x 10(exp 6). The wind tunnel results were correlated with in-flight flow visualizations and handling qualities trends obtained by NASA using an F-18 High-Alpha Research Vehicle (HARV) and by the Navy and McDonnell Douglas on F-18 aircraft with LEX fences added to improve the vertical tail buffet environment. Key issues that were addressed include the sensitivity of the vortical flows to the Reynolds number and Mach number; the reduced vertical tail excitation, and the corresponding flow mechanism, in the presence of the LEX fence; the repeatability of data obtained during high angle-of-attack wind tunnel testing of F-18 models; the effects of particle seeding for flow visualization on the quantitative model measurements; and the interpretation of off-body flow visualizations obtained using different illumination and particle seeding techniques. Erickson, Gary E. Glenn Research Center F-18 AIRCRAFT; FOREBODIES; INTERACTIONAL AERODYNAMICS; LEADING EDGES; VORTEX BREAKDOWN; VORTICES; WIND TUNNEL TESTS; WINGS; ANGLE OF ATTACK; BUFFETING; FLOW VISUALIZATION; MACH NUMBER; REYNOLDS NUMBER; STABILIZERS (FLUID DYNAMICS); SUBSONIC SPEED; TAIL ASSEMBLIES; TRANSONIC SPEED; TRANSONIC WIND TUNNELS...

Download or read book Wind Tunnel Investigation of Vortex Flows on F A 18 Configuration at Subsonic Through Transonic Speeds written by Gary E. Erickson and published by . This book was released on 1991 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1972 with total page 1056 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Post support and Wind tunnel Wall Interference on Flow Field about Subsonic High lift High speed Research Configuration written by Wendy B. Lessard and published by . This book was released on 2000 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study was performed to determine how significant the interference effects of the wind-tunnel model support system and tunnel walls can be for a high-speed configuration during takeoff and landing conditions. A 5-percent scale model of the Technology Concept Airplane was recently tested in the Langley 14- by 22-Foot Subsonic Tunnel. The model was numerically modeled with and without the support and tunnel walls and compared with experimental data. Detailed analysis of the flow provided additional insight concerning what effects the postsupport and tunnel walls had on the flow field. This study revealed that although the overall forces and moments could be experimentally accounted for, the detailed flow features, such as the surface pressure distributions, could not be accurately simulated without including the post in the computations.

Download or read book Wind tunnel Studies at Subsonic and Transonic Speeds of a Multiple mission Variable wing Sweep Airplane Configuration written by William J. Alford and published by . This book was released on 1959 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind tunnel Investigation of the Aerodynamic Characteristics of a Model Representative of a Supersonic Fighter class Airplane with an External flow Jet augmented Flap in Low speed Flight written by William A. Newsom and published by . This book was released on 1959 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind tunnel Investigation of the Low speed High lift Aerodynamics of a One fifth Scale Variable sweep Supersonic Transport written by Anthony M. Cook and published by . This book was released on 1968 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Tunnel Investigation of Effect of Yaw on Lateral stability Characteristics written by Isidore G. Recant and published by . This book was released on 1942 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combinations of an NACA 23012 tapered wing and a circular fuselage having a wedge-shaped rear were tested in the NACA 7- by 10-foot wind tunnel to determine the effect of wing-fuselage interference on the lateral-stability of wing-fuselage interference on the lateral-stability characteristics. The model configurations represented a high-wing, a mid-wing, and a low-wing monoplane. For each configuration, tests were made with a partial-span split flap neutral and deflected 60 degrees and with and without a vertical tail. Tests of the fuselage alone and of the fuselage with the vertical tail were also made.

Download or read book Investigation of a Technique for Measuring Dynamic Ground Effect in a Subsonic Wind Tunnel written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-20 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: To better understand the ground effect encountered by slender wing supersonic transport aircraft, a test was conducted at NASA Langley Research Center's 14 x 22 foot Subsonic Wind Tunnel in October, 1997. Emphasis was placed on improving the accuracy of the ground effect data by using a "dynamic" technique in which the model's vertical motion was varied automatically during wind-on testing. This report describes and evaluates different aspects of the dynamic method utilized for obtaining ground effect data in this test. The method for acquiring and processing time data from a dynamic ground effect wind tunnel test is outlined with details of the overall data acquisition system and software used for the data analysis. The removal of inertial loads due to sting motion and the support dynamics in the balance force and moment data measurements of the aerodynamic forces on the model is described. An evaluation of the results identifies problem areas providing recommendations for future experiments. Test results are validated by comparing test data for an elliptical wing planform with an Elliptical wing planform section with a NACA 0012 airfoil to results found in current literature. Major aerodynamic forces acting on the model in terms of lift curves for determining ground effect are presented. Comparisons of flight and wind tunnel data for the TU-144 are presented.Graves, Sharon S.Langley Research CenterGROUND EFFECT (AERODYNAMICS); AERODYNAMIC FORCES; SUBSONIC WIND TUNNELS; WIND TUNNEL TESTS; DATA ACQUISITION; AIRCRAFT DESIGN; AERODYNAMIC CONFIGURATIONS; AIRCRAFT CONFIGURATIONS; SLENDER WINGS; WING PLANFORMS; SUPERSONIC TRANSPORTS; TU-144 AIRCRAFT; VERTICAL MOTION

Download or read book Wind tunnel Investigation of the Effect of Vertical Position of the Wing on the Side Flow in the Region of the Vertical Tail written by Isidore G. Recant and published by . This book was released on 1941 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of the air flow at the tail of a monoplane model was conducted in the NACA 7- by 10-foot wind tunnel to determine the cause of the change in vertical-tail effectiveness with a change in the vertical position of the wing on the fuselage and with flap deflection.

Download or read book Wind tunnel Investigation of the Effect of Porous Spoilers on the Wake of a Subsonic Transport Model written by and published by . This book was released on 1976 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diffuser Efficiency and Flow Process of Supersonic Wind Tunnels with Free Jet Test Section written by Rudolf Hermann and published by . This book was released on 1950 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the wind tunnel arrangement under consideration, the air leaves the Laval nozzle as a free jet and is recaptured by the diffuser, which is of the convergent-divergent design. A theoretical analysis of the flow process through this type of supersonic wind tunnel is presented and the diffuser efficiency is calculated for the case of equilibrium between test chamber pressure and pressure in the nozzle exit, assuming one-dimensional, in viscous, steady flow. Using the basic equations of continuity, energy and momentum flux through a bounding surface, an exact solution of the problem is obtained, which is applicable up to Mach number infinite. One of the basic results is, that in the recapturing zone of the diffuser a transition occurs from supersonic to subsonic flow, which is followed by an acceleration in the convergent portion up to sonic velocity at the second throat. The transition is not a normal shock and involves a total pressure loss greater than that of a normal shock at the test section Mach number. A mathematical solution with supersonic velocity after the transition process has no physical existence. A comprehensive comparison of the analytical results with available experiments in supersonic wind tunnels up to Mach number 4.4 regarding diffuser efficiency and second throat area shows good agreement.

Download or read book Preliminary Investigation at Supersonic Speeds of Triangular and Sweptback Wings written by Macon C. Ellis and published by . This book was released on 1949 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results from a supersonic wind-tunnel investigation of a series of thin triangular and sweptback wings are presented. The triangular wing series consisted of eight triangular wings of vertex angles such that a range of leading-edge postions both inside and outside the Mach cone at the test Mach numbers of 1.43 and 1.71 was obtained. The three swept wings had angles of sweep at 45, 55, and 63 degrees and were tested at a Mach number of 1.43.

Download or read book A Wind tunnel Investigation at a Mach Number of 2 01 of the Sonic boom Characteristics of Three Wing body Combinations Differing in Wing Longitudinal Location written by Odell A. Morris and published by . This book was released on 1962 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: