Recent Developments of Image Based Measurement Methods for Application to Transonic Flows in Industrial Wind Tunnels

Kompenhans, Jürgen; Agocs, Janos; Egami, Yasuhiro; Engler, Rolf; Fey, Uwe; Frahnert, Holger; Groot, Klaus de; Henne, Ulrich; Kirmse, Tania; Klein, Christian; Klinge, Falk; Konrath, Robert; Koop, Lars; Mattner, Hartmut; Otter, Dirk; Pallek, Dieter; Sachs, Werner; Schröder, Andreas; Stasicki, Boleslaw

doi:10.1016/s1000-9361(11)60291-4

Cited by 5 publications

(5 citation statements)

References 6 publications

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“…The correlation part is adapted from the particle image velocimetry technique (PIV) and hence places IPCT in the category of DIC techniques. The method has been introduced by the German Aerospace Center DLR in 2004 [12,13]. Major development steps of the technology with multiple application examples were carried out within the framework of the two follow-up research projects advanced in-flight measurement techniques (AIM) and advanced in-flight measurement techniques 2 (AIM 2 ) coordinated by the German Aerospace Center DLR and co-funded by the European Commission [14][15][16].…”

Section: Principles Of the Ipctmentioning

confidence: 99%

Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

Bakunowicz

Święch

Meyer

2016

Meas. Sci. Technol.

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In aeronautical research experimental data sets of high quality are essential to verify and improve simulation algorithms. For this reason the experimental techniques need to be constantly refined. The shape, movement or deformation of structural aircraft elements can be measured implicitly in multiple ways; however, only optical, correlation-based techniques are able to deliver direct high-order and spatial results. In this paper two different optical metrologies are used for on-ground preparation and the actual execution of in-flight wing deformation measurements on a PW-6U glider. Firstly, the commercial PONTOS system is used for static tests on the ground and for wind tunnel investigations to successfully certify an experimental sensor pod mounted on top of the test bed fuselage. Secondly, a modification of the glider is necessary to implement the optical method named image pattern correlation technique (IPCT), which has been developed by the German Aerospace Center DLR. This scientific technology uses a stereoscopic camera set-up placed inside the experimental pod and a stochastic dot matrix applied to the area of interest on the glider wing to measure the deformation of the upper wing surface in-flight. The flight test installation, including the preparation, is described and results are presented briefly. Focussing on the compensation for typical error sources, the paper concludes with a recommended procedure to enhance the data processing for better results. Within the presented project IPCT has been developed and optimized for a new type of test bed. Adapted to the special requirements of the glider, the IPCT measurements were able to deliver a valuable wing deformation data base which now can be used to improve corresponding numerical models and simulations.

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Section: Principles Of the Ipctmentioning

confidence: 99%

Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

Bakunowicz

Święch

Meyer

2016

Meas. Sci. Technol.

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“…do not have this problem, but they will provide only information at a single point). In the same application as described above, the objective was to determine the actual angle of attack of the delta-wing in transonic flow (H. Frahnert in Kompenhans et al, 2006a). It was suspected that the inclination of the model increases under wind-load.…”

Section: Multi-diagnostics In Flow Fieldsmentioning

confidence: 99%

“…Quantitatively measurable values of interest for aerodynamics are pressure (Pressure Sensitive Paint, PSP), velocity (Particle Image Velocimetry, PIV), location of transition lines (Temperature Sensitive Paint, TSP), density (Background Oriented Schlieren Method, BOS), and sound pressure (Acoustic Microphone Array Technique), in parallel with the determination of deformation (Image Pattern Correlation technique, IPCT) and position of the model in the wind tunnel (Position and Deformation Measurement System, PDMS); Kompenhans et al (2006aKompenhans et al ( , 2006b. Application is mainly performed in the scope of large industrial projects in European co-operation.…”

Section: Introductionmentioning

confidence: 99%

Experimental methods for multi-diagnostics of flow fields in wind tunnels

Kompenhans

2007

J Vis

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“…Based on the technology of PIV, many applications were carried out by German Aerospace Center (DLR) [1], ranging from low speed flows to transonic flows, from high lift configurations to propellers and rotors, from wake vortex investigations in catapult facilities and water towing tanks to investigations of vortex break-down phenomena on delta wings. However, the PIV method needs to put tracer particles into the field and track them by light beam.…”

Section: Introductionmentioning

confidence: 99%

Full-field wing deformation measurement scheme for in-flight cantilever monoplane based on 3D digital image correlation

Li¹,

Liang²,

Guo³

et al. 2014

Meas. Sci. Technol.

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In this paper, a new non-contact scheme, based on 3D digital image correlation technology, is presented to measure the full-field wing deformation of in-flight cantilever monoplanes. Because of the special structure of the cantilever wing, two conjugated camera groups, which are rigidly connected and calibrated to an ensemble respectively, are installed onto the vertical fin of the aircraft and record the whole measurement. First, a type of pre-stretched target and speckle pattern are designed to adapt the oblique camera view for accurate detection and correlation. Then, because the measurement cameras are swinging with the aircraft vertical trail all the time, a camera position self-correction method (using control targets sprayed on the back of the aircraft), is designed to orientate all the cameras’ exterior parameters to a unified coordinate system in real time. Besides, for the excessively inclined camera axis and the vertical camera arrangement, a weak correlation between the high position image and low position image occurs. In this paper, a new dual-temporal efficient matching method, combining the principle of seed point spreading, is proposed to achieve the matching of weak correlated images. A novel system is developed and a simulation test in the laboratory was carried out to verify the proposed scheme.

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Recent Developments of Image Based Measurement Methods for Application to Transonic Flows in Industrial Wind Tunnels

Cited by 5 publications

References 6 publications

Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

Experimental methods for multi-diagnostics of flow fields in wind tunnels

Full-field wing deformation measurement scheme for in-flight cantilever monoplane based on 3D digital image correlation

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