Design of high-Reynolds-number flat-plate experiments in the NTF final report

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Published by Dept. of Mechanical and Aerospace Engineering, Arizona State University in Tempe, Ariz .

Written in English

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Subjects:

  • Aeronautics -- Research.,
  • Aeronautical laboratories.

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Other titlesDesign of high Reynolds number flat plate experiments in the NTF.
Statementby William S. Saric.
SeriesNASA-CR -- 184627., NASA contractor report -- NASA CR-184627.
ContributionsUnited States. National Aeronautics and Space Administration.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL18032582M

Download Design of high-Reynolds-number flat-plate experiments in the NTF

Get this from a library. Design of high-Reynolds-number flat-plate experiments in the NTF: final report. [W S Saric; United States.

National Aeronautics and Space Administration.]. Abstract: The design of an experiment to measure skin friction and turbulent boundary layer characteristics at Reynolds numbers exceeding 1 x 10 to the 9th is described.

The experiment will be conducted in a zero-pressure-gradient flow on a flat plate in the National Transonic Facility (NTF).Cited by: 2.

The design of an experiment to measure skin friction and turbulent boundary layer characteristics at Reynolds numbers exceeding 1 x 10 to the 9th is described. The experiment will be conducted in a zero-pressure-gradient flow on a flat plate in the National Transonic Facility (NTF).Author: William S.

Saric. The design of an experiment to measure skin friction and turbulent boundary-layer characteristics at Reynolds numbers exceeding 1 x is described. The experiment will be conducted in a zero-pressure-gradient flow on a flat plate in the National Transonic Facility (NTF).

The design of an experiment to measure skin friction and turbulent boundary-layer characteristics at Reynolds numbers exceeding one billion is described. The experiment will be conducted in a zero-pressure-gradient flow on a flat plate in the National Transonic : W. Saric and Jr.

Peterson. A flat plate boundary layer experiment is designed to examine the physical mechanism and the performance of vortex generator jets at Reynolds numbers up to Reθ = The investigation of vortex generator jets at this flow state is of fundamental importance for the assessment of flow control at takeoff and landing conditions.

NASA High-Reynolds Number Circulation Control Research - Overview of CFD and Planned Experiments (Invited) W. Milholen 11*, G.S. Jones^ and CM.

Cagle* NASA Langley Research Center, Hampton, VA, A new capability to test active flow control concepts and propulsion simulations at high Reynolds numbers in the National Transonic.

The experiments cover Reynolds number range from 4, to 80, Stereoscopic particle image velocimetry (PIV) measurements within the tank provide accurate measurements of all three components of velocity.

For each tank, at each rotational speed instantaneous phase-locked measurements were. NTF WT Experiments and CFD Validation Validate Skin Friction Predictions 3. CFD Predictions of between simple flat plate theory skin friction predic tions on the airplane and on the wind tunnel model at the When is testing at high Reynolds number required.

Can CFD codes, validated with low Reynolds number data, adequately predict forces. Take flow past a flat plate for example. The characteristics of flow past a flat plate with finite length L subject to different Reynolds numbers (Re = ρ UL/ μ) are shown in the figures.

At a low Reynolds number (Re = ), the presence of the flat plate is felt in a relatively large area where the viscous effects are important. In the past decade, much has been learned about heat transfer in liquid helium because of the need to cool superconducting magnets and other devices.

The topic of the Seventh Oregon Conference on Low Temperature Physics was an applied one, namely the use of liquid and gaseous helium to generate high Reynolds number flows. The design of an experiment to measure skin friction and turbulent boundary-layer characteristics at Reynolds numbers exceeding one billion is described.

The experiment will be conducted in a. We report on near-wall particle-tracking velocimetry (PTV) measurements in the turbulent boundary layer that forms on a hydraulically smooth flat plate.

The experiments were performed on a m-long test model in the US Navy's W.B. Morgan Large Cavitation Channel at flow speeds up to 20 m/s for downstream-distance-based Reynolds numbers up to and exceeding.

The present study is a first application of the Tomo-PIV technique at high Reynolds number (Re= ) in the turbulent flow past a thin flat plate. The experiments have been carried out in the S4 wind tunnel of IMFT. The high Reynolds number and the gas flow represented difficult aspects to overcome in order to achieve the present Tomo-PIV.

Although a flat-plate experiment was originally proposed by [Saric & Peterson] 32, it posed too many problems in the high-dynamic, environment of the NTF. EXPERIMENT 8: Boundary layer flow over a flat plate In high Reynolds number flow (Re >> 1), a thin boundary-layer is formed over a solid surface.

Viscous effects are confined within this layer (of thickness) and potential flow prevails outside it. At any position x, the boundary-layer is thin in the sense that 1 x.

Resolution of the turbulence is a fundamental problem for most high Reynolds number experiments. In this study the near-wall turbulence data are only well resolved for the lower two Reynolds number cases, since the length of the hot wire in viscous units is 4, 11, 25, and 45 for Reynolds numbers of,and 15respectively.

American Institute of Aeronautics and Astronautics Sunrise Valley Drive, Suite Reston, VA Figure 1 Curve of neutral stability for neutral disturbances on a flat plate at zero incidence from Schubauer and Skramstad (). The minimum Reynolds number on the stability curve on flat plate is.

U cs 1 1 s = = ∞ ν δ Reδ, (6) where δ 1 is the displacement thickness. At lower Reynolds numbers all disturbances. Osborne Reynolds conducted the experiment in the year This was conducted to demonstrate the existence of two types of flow: r Flow ent Flow 5.

r Flow: Laminar flow is defined as that type of flow in which the fluid particles move along well-defined paths or stream lines and all the stream lines are straight and. An experimental and theoretical investigation of instabilities in hypersonic flat plate boundary layer flow Physics of Fluids, Vol.

7, No. 4 Design of Mach quiet nozzles for the NASA Langley Supersonic Low-Disturbance Pilot Tunnel. Gas flow over a flat-plate airfoil at very-low Reynolds number is investigated in order to understand the aerodynamic issues related to micro air vehicle design and performance.

Studies have shown that such low Reynolds number flow exhibits rarefied phenomena and a flat plate having a thickness ratio of 5% has better aerodynamic performance.

The near-wall, subgrid-scale (SGS) model [Chung and Pullin, "Large-eddy simulation and wall-modeling of turbulent channel flow", J. Fluid Mech. ()] is used to perform large-eddy simulations (LES) of the incompressible developing, smooth-wall, flat-plate turbulent boundary layer.

In this model, the stretched-vortex, SGS closure is utilized in conjunction with. The National Transonic Facility (NTF) at Langley is a high pressure, cryogenic, closed-circuit wind tunnel with a Mach number range from to and a Reynolds number range of 4 x 10 6 to x 10 6 per foot.

The test section has 12 slots and 14 reentry flaps in the ceiling and floor. Wall-bounded turbulent flows at high Reynolds numbers have become an increasingly active area of research in recent years.

Many challenges remain in theory, scaling, physical understanding, experimental techniques, and numerical simulations. In this paper we distill the salient advances of recent origin, particularly those that challenge textbook orthodoxy. The turbulent flat plate boundary layer velocity profile: The time-averaged turbulent flat plate (zero pressure gradient) boundary layer velocity profile is much fuller than the laminar flat plate boundary layer profile, and therefore has a larger slope u/ y at the wall, leading to greater skin friction drag along the wall.

This is the reason why boundary layers are thin in high Reynolds number flows because the fluid is being convected along the flow direction at a much faster rate than the spreading of the boundary layer, which is normal to the flow direction.

References. Batchelor, G K (), An Introduction to Fluid Dynamics, Cambridge University Press. Abstract. Consideration is given to liquid and gaseous helium as test fluids, high Reynolds number test requirements in low speed aerodynamics, the measurement of subsonic flow around an appended body of revolution at cryogenic conditions in the NTF, water tunnels, flow visualization, the six component magnetic suspension system for wind tunnel testing, and.

I was hoping just to refer you to Wikepedia’s page, Reynolds number, but I actually am not very happy with some of what it says there.

Right off the bat, I do not agree with the following statement from that website: > The Reynolds number is defin. In boundary layer flow over a flat plate, experiments confirm that, after a certain length of flow, a laminar boundary layer will become unstable and turbulent.

This instability occurs across different scales and with different fluids, usually when Re x ≈ 5 × 10 5, where x is the distance from the leading edge of the flat plate, and the flow velocity is the freestream velocity of the fluid.

The objective of this lecture focuses on the design of airfoils for low Reynolds numbers, which has been the subject of considerable research as documented in several major con-ferences and books.5{9 First, various approaches to airfoil design are discussed, leading to the use of inverse methods being favored over the alternatives.

This book reports the latest development and trends in the low Re number aerodynamics, transition from laminar to turbulence, unsteady low Reynolds number flows, experimental studies, numerical transition modelling, control of low Re number flows, and MAV wing aerodynamics.

The contributors to each chapter are fluid mechanics and aerodynamics. This calculator computes the Reynolds Number given the flow characteristics asked for below. It outputs the flow type you can expect (laminar, transitional, or turbulent) based on the Reynolds Number of the Characteristic Distance as the distance from the leading edge (where the fluid first makes contact) for flow over a plate, or as the pipe diameter for flow inside a pipe.

Figure 1. (a) The Reynolds experiment for visualizing flow regimes, (b) dye pattern for laminar flow, (c) dye pattern for turbulent flow. This experiment could be repeated with several pipes of different diameter; however, a dimensional analysis will indicate that the criterion for distinguishing between these flows is the Reynolds number.

Reynolds number is a dimensionless quantity that states whether the flow of a fluid on a surface is laminar or turbulent in nature. The world of science is f. HIGH REYNOLDS NUMBER ANALYSIS OF FLAT PLATE AND SEPARATED AFTERBODY FLOW USING NON-LINEAR TURBULENCE MODELS John R.

Carlson NASA Lan gley Researhc Center Hampton, AV Abstract The ab ility o f the three- dimensional Na vier-Stoesk method, ABP 3D, to sim ulate the e ect of Reynolds num-ber ariationv using non-linear e xplicit algebraic. heat transfer. Nusselt Number for Forced Convection.

Heat Transfer Engineering Thermodynamics Engineering Physics. In heat transfer at a boundary (surface) within a fluid, the Nusselt number (Nu) is the ratio of convective to conductive heat. The Flat Plate Airfoil (Dcd) Planar Airfoil Performance (Dce) Finite Span Performance (Dcf) Design of Experiments (Kb) Experimental Techniques (Kc) Introduction (Kca) Auto- and Cross-Correlation High Reynolds Number (Neb) Sphere Flow - Low Reynolds Number (Nec) Molecular Effects (Ned).

Drag on a Flat Plate in Low-Reynolds-Number Gas Flows Quanhua Sun∗ and Iain D. Boyd† University of Michigan, Ann Arbor, Michigan Airflow over a flat plate at zero incidence is investigated as a function of the Reynolds number Re and the Mach number M under subsonic, low-Reynolds-number conditions.

The flows are simulated using the. Where, R e is the Reynolds number; ρ is the density of the fluid; V is the velocity of flow; D is the pipe diameter; μ is the viscosity of the fluid; If the Reynolds number calculated is high (greater than ), then the flow through the pipe is said to be turbulent.

Critical Reynolds number for a flow over flat plate is x 10^5. Velocity of the air (25 degrees celcius) flowing over a flat plate is 20 m/s. Assuming velocity doesnt change along the plate, calculate the critical length along the flate plate, which will make the flow turbulent.

What wil happen if the air temperature becomes degrees celcius.A. Roshko, “ Experiments on the flow past a circular cylinder at very high Reynolds number,” J. Fluid Mech. 10, (). Google Scholar Crossref; 4. P. W. Bearman, “ Investigation of the flow behind a two-dimensional model with a blunt trailing edge and fitted with splitter plate,” J.

Fluid Mech. 21, (). Google Scholar.Aerodynamic design and thermal management are some of the most important tasks when developing new concepts for the flow around tractor-trailers. Today, both experimental and numerical studies are an integral part of the aerodynamic and thermal design processes.

A variety of studies have been conduc.

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