Towards time-resolved multi-property measurements by filtered Rayleigh scattering: diagnostic approach and verification.

TY - JOUR

T1 - Towards time-resolved multi-property measurements by filtered Rayleigh scattering: diagnostic approach and verification.

AU - Doll, Ulrich

AU - Kapulla, Ralf

AU - Dues, Michael

AU - Steinbock, Jonas

AU - Melnikov, Sergey

AU - Röhle, Ingo

AU - Migliorini, Matteo

AU - K. Zachos, Pavlos

PY - 2024/1

Y1 - 2024/1

N2 - 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 and 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 ± 2 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.

AB - 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 and 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 ± 2 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.

UR - http://www.scopus.com/inward/record.url?scp=85179184330&partnerID=8YFLogxK

U2 - 10.1007/s00348-023-03740-6

DO - 10.1007/s00348-023-03740-6

M3 - Journal article

SN - 0723-4864

VL - 65

JO - Experiments in Fluids

JF - Experiments in Fluids

IS - 1

M1 - 2

ER -