Detailed Flow-Field Measurements Over a 75 Deg Swept Delta Wing

Detailed Flow-Field Measurements Over a 75 Deg Swept Delta Wing

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-07

Total Pages: 46

ISBN-13: 9781722155445

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Results from an experimental investigation documenting the flowfield over a 75 deg swept delta wing at an angle-of-attack of 20.5 deg are presented. Results obtained include surface flow visualization, off-body flow visualization, and detailed flowfield surveys for various Reynolds numbers. Flowfield surveys at Reynolds numbers of 0.5, 1.0, and 1.5 million based on the root chord were conducted with both a Pitot pressure probe and a 5-hole pressure probe; and 3-component laser velocimeter surveys were conducted at a Reynolds number of 1.0 million. The Pitot pressure surveys were obtained at 5 chordwise stations, the 5-hole probe surveys were obtained at 3 chordwise stations and the laser velocimeter surveys were obtained at one station. The results confirm the classical roll up of the flow into a pair of primary vortices over the delta wing. The velocity measurements indicate that Reynolds number has little effect on the global structure of the flowfield for the Reynolds number range investigated. Measurements of the non-dimensional axial velocity in the core of the vortex indicate a jet like flow with values greater than twice freestream. Comparisons between velocity measurements from the 5-hole pressure probe and the laser velocimeter indicate that the pressure probe does a reasonable job of measuring the flowfield quantities where the velocity gradients in the flowfield are low. Kjelgaard, Scott O. and Sellers, William L., III Langley Research Center RTOP 505-60-11-03...


Laser Velocimetry Measurements of Vortex Flows on a Delta Wing at Mach 1.9

Laser Velocimetry Measurements of Vortex Flows on a Delta Wing at Mach 1.9

Author: Linda G. Smith

Publisher:

Published: 1993

Total Pages: 120

ISBN-13:

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Off-body flow visualizations and fluid velocity measurements are conducted in a supersonic vortex flow. Three-dimensional laser velocimetry measurements are made in the leeward flowfield over a simple sharp-edged delta wing with 75 degree sweep angle. Tests are conducted at Mach 1.9 and Reynolds number of 2.4 x 10(exp 6) based on model root chord. Measurements are made at 40% and 80% chord positions for 20 and 30 degree angles of attack and at 40% chord for 35 degrees. Mean velocities and turbulence intensities are measured on the five planes. Measurement accuracy is discussed in detail. The measurements define the location of the vortex core and provide the flowfield velocities surrounding the vortex. The difficulties inherent with seeding high velocity vortex flows are discussed ... Laser Velocimetry Measurement of Vortical Flowfields.


Special Course on Aircraft Dynamics at High Angles of Attack: Experiments and Modelling

Special Course on Aircraft Dynamics at High Angles of Attack: Experiments and Modelling

Author: North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Fluid Dynamics Panel. Special Course

Publisher:

Published: 1991

Total Pages: 154

ISBN-13:

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"This report consists of lecture notes of an AGARD Fluid Dynamics Panel Special Course. These notes provide the latest information on the development and use of dynamic experiments in wind tunnels from several of the NATO nations. They address current oscillatory and rotary test techniques, experimental results for typical configurations, and the use of these data for flight mechanics applications. Subject included are: dynamic lift, wing rock, fluid dynamics of rotary flows, mathematical modelling, non-linear data representation, vortex manipulation for control enhancement, and correlations of predictions based on rotary and oscillatory wind-tunnel and flight-test results. The complete course notes are contained in two volumes. The main part of the notes is contained in AGARD Advisory Report 265 (ADA235179). The present volume includes papers on: Unsteady aerodynamics of slender wings; Dynamic stall effects and applications to high performance aircraft; Oscillatory test techniques; Large amplitude oscillations; Oscillatory data for typical configurations; and Forebody vortex control."--Stinet.