caa a22 4500 606199063 CHVBK 20210128100936.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00348-015-2068-6 doi (NATIONALLICENCE)springer-10.1007/s00348-015-2068-6 Investigations of air flow behavior past a conical bluff body using particle imaging velocimetry [Elektronische Daten] [Marcin Dutka, Mario Ditaranto, Terese Løvås] An annular jet flow past conical bluff body in an original configuration was investigated using particle imaging velocimetry for Reynolds (Re) numbers between 4900 and 58,800. The studied geometrical configuration finds its application in a novel low NO x burner; therefore, the flow conditions corresponding to burner operation were investigated in detail. It was found that the flow is laminar at Re=4900 and the transition from a laminar to a turbulent flow regime starts at Re=9800-14,700. The length of the recirculation zone increases abruptly when the flow becomes turbulent and is independent of the Re number within the turbulent flow regime. The fraction of the total flow rate representing flow circulating in the recirculation zone is relatively constant for the investigated flows. An increase in main stream velocity implies proportional decrease in the residence time in the recirculation zone observed within the turbulent flow regime. Two types of coherent structures shed from the trailing edge of the bluff body are identified using proper orthogonal decomposition technique. The first is vortices that cross the centerline of the bluff body and travel downstream along the centerline. The second is smaller vortex structures that are shed alternately from the trailing edge of the bluff body. Springer-Verlag Berlin Heidelberg, 2015 Dutka Marcin Department of Energy and Process Engineering, Norwegian University of Science and Technology, Kolbjørn Hejes vei 1b, 7491, Trondheim, Norway aut Ditaranto Mario SINTEF Energy Research, Sem Sælands vei 11, 7034, Trondheim, Norway aut Løvås Terese Department of Energy and Process Engineering, Norwegian University of Science and Technology, Kolbjørn Hejes vei 1b, 7491, Trondheim, Norway aut Experiments in Fluids Springer Berlin Heidelberg 56/11(2015-11-01), 1-16 0723-4864 56:11<1 2015 56 348 https://doi.org/10.1007/s00348-015-2068-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-2068-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dutka Marcin Department of Energy and Process Engineering, Norwegian University of Science and Technology, Kolbjørn Hejes vei 1b, 7491, Trondheim, Norway aut NATIONALLICENCE 700 1- Ditaranto Mario SINTEF Energy Research, Sem Sælands vei 11, 7034, Trondheim, Norway aut NATIONALLICENCE 700 1- Løvås Terese Department of Energy and Process Engineering, Norwegian University of Science and Technology, Kolbjørn Hejes vei 1b, 7491, Trondheim, Norway aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/11(2015-11-01), 1-16 0723-4864 56:11<1 2015 56 348