Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration
Само за регистроване кориснике
2020
Конференцијски прилог (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт
Existing wind tunnel in the Laboratory for Hydraulic machinery and energy systems, Faculty of Mechanical Engineering, University of Belgrade, is redesigned, by adding axial fan regulated by the inverter at the tunnel inlet and flow straightener in the pipe before the carefully profiled Witoshinsky nozzle. Various anemometers could be calibrated in the axisymmetric uniform jet after the nozzle with inner diameter of 145 mm. In this paper are presented experimental results of the flow uniformity and turbulence levels, as well as skewness and flatness distributions for various flow regimes in the wind tunnel measurement section by one-component laser Doppler anemometry (LDA) along the horizontal radius in 27 points. Time-averaged axial velocity profiles have been obtained for twenty Reynolds numbers in the interval Re = 1780 to 148869, determined for point on the jet axis r/R =0. Uniform velocity profiles are obtained in the jet core region, i.e. up to r/R = 0,9 for all Reynolds numbers e...xcept the lowest one. Turbulence levels have been also reported for all these cases and achieved turbulence levels were below 2% in the free jet core region for almost all measuring points and regimes, what follows standard ISO 17713-1 requirements. Achieved validation was high. Sampling rate varied and in most of the cases was in average 250-400 Hz. Thermal fog seeding was applied at the calibration tunnel inlet, i.e. at the axial fan suction side.
Кључне речи:
wind tunnel / anemometers calibration / ISO 17713-1:2007 / turbulence / LDAИзвор:
Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013., 2020Финансирање / пројекти:
- Примена савремених мерних и прорачунских техника за изучавање струјних параметара вентилационих система на моделу енергетски изузетно ефикасног (пасивног) објекта (RS-MESTD-Technological Development (TD or TR)-35046)
- Bilateral project “Joint Research on the Development Technology of Low-head Run-of-the-river Hydropower”, between MESTD RS and Ministry of Water Resources in China and Renewable Energy and Rural Electrification Zhejiang International Science Center
Колекције
Институција/група
Mašinski fakultetTY - CONF AU - Janković, Novica AU - Jeremić, Đorđe AU - Čantrak, Đorđe AU - Ilić, Dejan PY - 2020 UR - https://machinery.mas.bg.ac.rs/handle/123456789/5261 AB - Existing wind tunnel in the Laboratory for Hydraulic machinery and energy systems, Faculty of Mechanical Engineering, University of Belgrade, is redesigned, by adding axial fan regulated by the inverter at the tunnel inlet and flow straightener in the pipe before the carefully profiled Witoshinsky nozzle. Various anemometers could be calibrated in the axisymmetric uniform jet after the nozzle with inner diameter of 145 mm. In this paper are presented experimental results of the flow uniformity and turbulence levels, as well as skewness and flatness distributions for various flow regimes in the wind tunnel measurement section by one-component laser Doppler anemometry (LDA) along the horizontal radius in 27 points. Time-averaged axial velocity profiles have been obtained for twenty Reynolds numbers in the interval Re = 1780 to 148869, determined for point on the jet axis r/R =0. Uniform velocity profiles are obtained in the jet core region, i.e. up to r/R = 0,9 for all Reynolds numbers except the lowest one. Turbulence levels have been also reported for all these cases and achieved turbulence levels were below 2% in the free jet core region for almost all measuring points and regimes, what follows standard ISO 17713-1 requirements. Achieved validation was high. Sampling rate varied and in most of the cases was in average 250-400 Hz. Thermal fog seeding was applied at the calibration tunnel inlet, i.e. at the axial fan suction side. C3 - Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013. T1 - Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration UR - https://hdl.handle.net/21.15107/rcub_machinery_5261 ER -
@conference{ author = "Janković, Novica and Jeremić, Đorđe and Čantrak, Đorđe and Ilić, Dejan", year = "2020", abstract = "Existing wind tunnel in the Laboratory for Hydraulic machinery and energy systems, Faculty of Mechanical Engineering, University of Belgrade, is redesigned, by adding axial fan regulated by the inverter at the tunnel inlet and flow straightener in the pipe before the carefully profiled Witoshinsky nozzle. Various anemometers could be calibrated in the axisymmetric uniform jet after the nozzle with inner diameter of 145 mm. In this paper are presented experimental results of the flow uniformity and turbulence levels, as well as skewness and flatness distributions for various flow regimes in the wind tunnel measurement section by one-component laser Doppler anemometry (LDA) along the horizontal radius in 27 points. Time-averaged axial velocity profiles have been obtained for twenty Reynolds numbers in the interval Re = 1780 to 148869, determined for point on the jet axis r/R =0. Uniform velocity profiles are obtained in the jet core region, i.e. up to r/R = 0,9 for all Reynolds numbers except the lowest one. Turbulence levels have been also reported for all these cases and achieved turbulence levels were below 2% in the free jet core region for almost all measuring points and regimes, what follows standard ISO 17713-1 requirements. Achieved validation was high. Sampling rate varied and in most of the cases was in average 250-400 Hz. Thermal fog seeding was applied at the calibration tunnel inlet, i.e. at the axial fan suction side.", journal = "Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013.", title = "Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration", url = "https://hdl.handle.net/21.15107/rcub_machinery_5261" }
Janković, N., Jeremić, Đ., Čantrak, Đ.,& Ilić, D.. (2020). Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration. in Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013.. https://hdl.handle.net/21.15107/rcub_machinery_5261
Janković N, Jeremić Đ, Čantrak Đ, Ilić D. Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration. in Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013.. 2020;. https://hdl.handle.net/21.15107/rcub_machinery_5261 .
Janković, Novica, Jeremić, Đorđe, Čantrak, Đorđe, Ilić, Dejan, "Flow Uniformity and Turbulence Level Measurements by LDA in the Wind Tunnel for Anemometers Calibration" in Proceedings, 9th International Scientific Conference on Defensive Technologies, OTEH 2020, Belgrade, Serbia, 15-16 October 2020., Session Quality, Standardization, Metrology, Maintenance and Exploitation, 6 pages, paper no. 013. (2020), https://hdl.handle.net/21.15107/rcub_machinery_5261 .