• Media type: E-Article
  • Title: Towards time-resolved multi-property measurements by filtered Rayleigh scattering: diagnostic approach and verification
  • Contributor: Doll, Ulrich; Kapulla, Ralf; Dues, Michael; Steinbock, Jonas; Melnikov, Sergey; Röhle, Ingo; Migliorini, Matteo; Zachos, Pavlos K.
  • imprint: Springer Science and Business Media LLC, 2024
  • Published in: Experiments in Fluids
  • Language: English
  • DOI: 10.1007/s00348-023-03740-6
  • ISSN: 0723-4864; 1432-1114
  • Keywords: Fluid Flow and Transfer Processes ; General Physics and Astronomy ; Mechanics of Materials ; Computational Mechanics
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:p>The use of multiple perspective views is a possible pathway towards the combined measurement of multiple time-resolved flow properties by filtered Rayleigh scattering (FRS). In this study, a six view observation concept is experimentally verified on a aspirated pipe flow. The concept was introduced in our previous work, and it has the ability to simultaneously measure high-accuracy time-averaged <jats:italic>and</jats:italic> time-resolved three-component velocity, pressure and temperature fields. To simulate time-resolution, multi-view FRS data at a single optimised excitation frequency are selected and processed for multiple flow properties. Time-averaged and quasi-time-resolved FRS results show very good agreement with differential pressure probe measurements and analytical temperature calculations and lie within <jats:inline-formula><jats:alternatives><jats:tex-math>$$\pm 2$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>±</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> m/s of complementary laser Doppler anemometry (LDA) velocity measurements for all operating points. The introduction of a multistage fitting procedure for the time-resolved analysis leads to a significant improvement of the precision by factors of 4 and 3 for temperature and axial velocity and 18 for pressure. Moreover, both processing methods show their capacity to resolve flow structures in a swirling flow configuration. It is demonstrated that the developed multi-view concept can be used to determine multiple flow variables from a single-frequency measurement, opening the path towards time-resolved multi-parameter measurements by FRS. </jats:p>