Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side
Апстракт
Some aspects of the laser Doppler anemometry (LDA) investigation of the turbulent swirl flow behind axial
fans in pipes, diffusers and jets are presented in this paper. All three installations have profiled bell mouth inlet,
while the fans are built-in in different ways. Namely, in the first case axial fan is built-in into the pipe
approximately 27.74D long, where D is average inner diameter D = 0.4 m. In the second case axial fan is builtin
into the straight conical diffuser with the inlet diameter 0.4 m and total divergence angle 8.6⁰, while in the
third case turbulent swirl jet flow behind the axial was observed. In all cases fan impeller rotation number is
varied. One-, as well as, two- and thee-component LDA systems were applied. Thermal fog seeding was
applied in all cases. Time averaged velocity profiles are analysed, as well as the statistical moments of the
second till the fourth order. In addition, distributions of the Reynolds stresses are also presented and
discuss...ed. Investigations reveal structures, as well as complexity of the three-dimensional, non-homogenous,
anisotropic turbulent swirl flows. This stochastic character on the instantaneous level was shown for all three
cases. Kolmogorov “-5/3 law” is shown in the case of the circumferential velocity distribution for the turbulent
swirl flow in the pipe for various measuring points. Phenomenon of the non-local turbulent transfer and nongradient
turbulent diffusion is studied. The influence of the axial fan duty point on the generated turbulence
structure is studied.
Кључне речи:
Turbulent swirl flow / axial fan / diffuser / pipe / jetИзвор:
International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65, 2020, 65-Финансирање / 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)
URI
http://cnntechno.com/docs/4_CNN_book_of_abstracts_CIP_Final.pdfhttps://machinery.mas.bg.ac.rs/handle/123456789/5571
Колекције
Институција/група
Mašinski fakultetTY - CONF AU - Čantrak, Đorđe AU - Janković, Novica AU - Ilić, Dejan PY - 2020 UR - http://cnntechno.com/docs/4_CNN_book_of_abstracts_CIP_Final.pdf UR - https://machinery.mas.bg.ac.rs/handle/123456789/5571 AB - Some aspects of the laser Doppler anemometry (LDA) investigation of the turbulent swirl flow behind axial fans in pipes, diffusers and jets are presented in this paper. All three installations have profiled bell mouth inlet, while the fans are built-in in different ways. Namely, in the first case axial fan is built-in into the pipe approximately 27.74D long, where D is average inner diameter D = 0.4 m. In the second case axial fan is builtin into the straight conical diffuser with the inlet diameter 0.4 m and total divergence angle 8.6⁰, while in the third case turbulent swirl jet flow behind the axial was observed. In all cases fan impeller rotation number is varied. One-, as well as, two- and thee-component LDA systems were applied. Thermal fog seeding was applied in all cases. Time averaged velocity profiles are analysed, as well as the statistical moments of the second till the fourth order. In addition, distributions of the Reynolds stresses are also presented and discussed. Investigations reveal structures, as well as complexity of the three-dimensional, non-homogenous, anisotropic turbulent swirl flows. This stochastic character on the instantaneous level was shown for all three cases. Kolmogorov “-5/3 law” is shown in the case of the circumferential velocity distribution for the turbulent swirl flow in the pipe for various measuring points. Phenomenon of the non-local turbulent transfer and nongradient turbulent diffusion is studied. The influence of the axial fan duty point on the generated turbulence structure is studied. C3 - International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65 T1 - Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side SP - 65 UR - https://hdl.handle.net/21.15107/rcub_machinery_5571 ER -
@conference{ author = "Čantrak, Đorđe and Janković, Novica and Ilić, Dejan", year = "2020", abstract = "Some aspects of the laser Doppler anemometry (LDA) investigation of the turbulent swirl flow behind axial fans in pipes, diffusers and jets are presented in this paper. All three installations have profiled bell mouth inlet, while the fans are built-in in different ways. Namely, in the first case axial fan is built-in into the pipe approximately 27.74D long, where D is average inner diameter D = 0.4 m. In the second case axial fan is builtin into the straight conical diffuser with the inlet diameter 0.4 m and total divergence angle 8.6⁰, while in the third case turbulent swirl jet flow behind the axial was observed. In all cases fan impeller rotation number is varied. One-, as well as, two- and thee-component LDA systems were applied. Thermal fog seeding was applied in all cases. Time averaged velocity profiles are analysed, as well as the statistical moments of the second till the fourth order. In addition, distributions of the Reynolds stresses are also presented and discussed. Investigations reveal structures, as well as complexity of the three-dimensional, non-homogenous, anisotropic turbulent swirl flows. This stochastic character on the instantaneous level was shown for all three cases. Kolmogorov “-5/3 law” is shown in the case of the circumferential velocity distribution for the turbulent swirl flow in the pipe for various measuring points. Phenomenon of the non-local turbulent transfer and nongradient turbulent diffusion is studied. The influence of the axial fan duty point on the generated turbulence structure is studied.", journal = "International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65", title = "Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side", pages = "65", url = "https://hdl.handle.net/21.15107/rcub_machinery_5571" }
Čantrak, Đ., Janković, N.,& Ilić, D.. (2020). Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side. in International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65, 65. https://hdl.handle.net/21.15107/rcub_machinery_5571
Čantrak Đ, Janković N, Ilić D. Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side. in International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65. 2020;:65. https://hdl.handle.net/21.15107/rcub_machinery_5571 .
Čantrak, Đorđe, Janković, Novica, Ilić, Dejan, "Observations from LDA Research of the Turbulent Swirl Flow on the Axial Fan Pressure Side" in International Conference of Experimental and Numerical Investigations and New Technolgies, CNN TECH 2020, Session: Clear sky, June 29-July 2, Zlatibor, Serbia, pp. 65 (2020):65, https://hdl.handle.net/21.15107/rcub_machinery_5571 .