Leading edge vortex flow computations and comparison with DNW-HST wind tunnel data

Computations are presented for the vortical flow around a sharp-edged cropped delta wing with 65° leading edge sweep using a computational method based on the Reynolds-averaged Navier-Stokes equations. It is demonstrated that turbulence modelling plays a crucial role in the ability to capture the vortical structures. Standard one- and two...

Vortex formation and flow separation: the beauty and the beast in aerodynamics. Lanchester 2000 lecture

Flow separation and vorticity generation are closely connected. When the flow leaves the trailing edge of a wing, a vorticity layer is formed, directly related to the lift of the wing and carrying streamwise vorticity. Boundary layers, in which the viscous flow very close to the wing surface is confined, carry vorticity in crosswise direction,...

Voorstel voor onderzoek naar de invloed van ruwheid op de weerstand van profielen met natuurlijke laminaire stroming

Dit memorandum bevat een voorstel voor onderzoek in het kader van NIVR Algemene Research naar de invloed van ruwheid op de weerstand van profielen met natuurlijke laminaire stroming (NLF-profielen), Het voorgestelde onderzoek valt uiteen in twee delen : . kwantificeren van onder operationele condities optredende verstoringen; ....

The international vortex flow experiment: A test case for compressible Euler codes

As part of the joint International Vortex Flow Experiment, force and pressure measurements have been carried out on a 65 deg delta wing configuration in the transonic and supersonic wind tunnels of NLR. Out of these data three test cases were selected by the organizing committee of the GAMM WORKSHOP on the "Numerical Simulation of Compressible...

Tests on the afwal 65° Delta wing at NLR: A study of vortex flow development between Mach =0,4 and 4

As part of the US/European Vortex Flow Experiment force and pressure measurements have been carried out in the transonic and supersonic wind tunnels of NLR on a 65° swept delta wing configuration. The larger part of the experimental results concerns a configuration with a sharp and one with a rounded leading edge, both tested over a range of...

Reynolds number effects and the wind tunnel environment

In the interpretation of windtunnel test results, obtained for a range of Reynolds numbers, it is not always clear if the observed variation in characteristics are due to a pure Reynolds number effect of that particular configuration or due to a variation of windtunnel characteristics with Reynolds number. The paper identifies some possible...

Mag het een "count" meer zijn? De windtunnel als weegschaal voor het vliegtuigontwerp

The paper discusses the quality of the wind tunnel for the experimental verification of aircraft design. The accuracy of the measurement of drag is used as a typical example to illustrate problems in wind tunnel testing like balance performance, determination of angle of incidence, wall- and support interference, scale effects and engine...

Voorstel tot experimentele verificatie van een berekeningsmethode voor transsone profielstromingen

Dit memorandum is opgesteld ten behoeve van het Nederlandse Instituut voor Vliegtuigontwikkeling en Ruimtevaart (NIVR).

Half-model testing in the NLR high speed tunnel HST : its technique and application

An evaluation is presented of the half-model test technique based on a systematic comparison of halfmodel test results with the corresponding full-model data. It is shown that the most important problems with this technique originate from half-model mounting and wall interference effects. At present, these effects can only be determined...

A report of a GARTEur Action Group on "Two-dimensional transonic testing methods"

A progress report is presented of a GARTEur Action Group on "Two-dimensional Transonic Testing Methods' As part of the action group activities measurements were made of the CAST-7/DOA1 airfoil in 7 European facilities, involving perforated, slotted and flexible wall wind tunnels. A comparison was made of the "best data available" for each tunnel...

Comparison of boundary layer calculations for the root section of a wing

At the workshop nine participants presented the results of their calculations for a practical test case. The test case deals with the 3D turbulent boundary layer development, including separation, on the root section of a swept wing. The employed calculation methods comprise 3D integral methods as well as field methods. A short description of...

Three-dimensional separation of an incompressible turbulent boundary layer on an infinite swept wing

An experiment is described in which a three-dimensional boundary layer flow under infinite swept wing conditions is simulated. A description is given of the development of the boundary layer in a region of an adverse pressure gradient leading to increased cross flows and finally terminating in a three-dimensional. separation. Measurements are...

Measurements of the Reynolds stress tensor in a three-dimensional turbulent boundary layer under infinite swept wing conditions

On a wind tunnel model measurements have been made of the six components of the Reynolds stress tensor in a three-dimensional incompressible turbulent boundary layer under infinite swept wing conditions in an adverse pressure gradient, with a three-dimensional separation near the trailing edge. These measurements complement the mean velocity...

Measurements in an incompressible three-dimensional turbulent boundary layer under infinite swept wing conditions and a comparison with theory

First a three-dimensional turbulent boundary-layer experiment is described. This experiment has been carried out with the specific aim to provide a test-case for calculation methods. Much attention has been paid to the design of the test set-up. An infinite swept wing flow has been simulated with good accuracy. The initially two-dimensional...

Measurements in a three-dimensional incompressible turbulent boundary layer in an adverse pressure gradient under infinite swept wing conditions

On a wind tunnel model, especially designed to check calculation methods, measurements were made of a three-dimensional turbulent boundary layer under infinite swept wing conditions in an adverse pressure gradient, with a three-dimensional separation near the trailing edge. Accurate measurements of the external flow field, the mean velocity...

A numerical model for a combustion-driven spherical implosion wave

Microwave measurements of projectile motion in the barrel of the UTIAS implosion-driven hypervelocity launcher