2D refractive index field measurements in air in different pressure scenarios

Download statistics - Document (COUNTER):

Beermann, R.; Quentin, L.; Reithmeier, E.; Kästner, M.: 2D refractive index field measurements in air in different pressure scenarios. In: Proceedings of SPIE 10819 (2018), 108190E. DOI: https://doi.org/10.1117/12.2500315

Repository version

To cite the version in the repository, please use this identifier: https://doi.org/10.15488/10249

Selected time period:

year: 
month: 

Sum total of downloads: 29




Thumbnail
Abstract: 
The optical geometry characterization of wrought hot components can help to quantify material distortion effects during air-cooling. The component's shrinkage behavior is affected by inhomogeneous heat dissipation due to the object's complex geometry and - in case of hybrid materials - differing thermal expansion coefficients. As optical triangulation techniques rely on the rectilinear expansion of light, the hot component's heat input into the surrounding medium air influences the reachable accuracy of optical geometry measurements due to an inhomogeneous refractive index field around the hot component. In previous work, the authors identified low pressure measurements in air as a possible approach to reduce the magnitude and expansion of the inhomogeneous refractive index field above cylindrical high-temperature objects and thereby allow precise geometry acquisition. We now present experimental data of the 2D refractive index field above a hot cylinder in different pressure scenarios using the well-known background oriented schlieren (BOS) method in order to illustrate the decrease in refractive index variations dependent on the pressure state. For this purpose, a ceramic rod is placed in a vacuum chamber and heated up to temperatures of about 1000°C. Using a monochromatic camera, a wavelet background and an optical ow algorithm, the developing 2D refractive index field for a low pressure scenario is compared to ambient pressure conditions. The experimental data illustrates a reduction in the convective heat flow above the hot heating rod at lower pressure values and therefore a homogenization of the density-coupled refractive index in air, validating former simulation results. © 2018 SPIE.
License of this version: Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Document Type: conferenceObject
Publishing status: publishedVersion
Issue Date: 2018
Appears in Collections:Fakultät für Elektrotechnik und Informatik

distribution of downloads over the selected time period:

downloads by country:

pos. country downloads
total perc.
1 image of flag of Germany Germany 16 55.17%
2 image of flag of United States United States 4 13.79%
3 image of flag of Czech Republic Czech Republic 3 10.34%
4 image of flag of United Kingdom United Kingdom 2 6.90%
5 image of flag of Russian Federation Russian Federation 1 3.45%
6 image of flag of Italy Italy 1 3.45%
7 image of flag of Indonesia Indonesia 1 3.45%
8 image of flag of Canada Canada 1 3.45%

Further download figures and rankings:


Hinweis

Zur Erhebung der Downloadstatistiken kommen entsprechend dem „COUNTER Code of Practice for e-Resources“ international anerkannte Regeln und Normen zur Anwendung. COUNTER ist eine internationale Non-Profit-Organisation, in der Bibliotheksverbände, Datenbankanbieter und Verlage gemeinsam an Standards zur Erhebung, Speicherung und Verarbeitung von Nutzungsdaten elektronischer Ressourcen arbeiten, welche so Objektivität und Vergleichbarkeit gewährleisten sollen. Es werden hierbei ausschließlich Zugriffe auf die entsprechenden Volltexte ausgewertet, keine Aufrufe der Website an sich.

Search the repository


Browse