TY - JOUR
T1 - Characterization of very-large-scale motions in high-Re pipe flows
AU - Discetti, Stefano
AU - Bellani, Gabriele
AU - Örlü, Ramis
AU - Serpieri, Jacopo
AU - Sanmiguel Vila, Carlos
AU - Raiola, Marco
AU - Zheng, Xiaobo
AU - Mascotelli, Lucia
AU - Talamelli, Alessandro
AU - Ianiro, Andrea
PY - 2019
Y1 - 2019
N2 - Very-large-scale structures in pipe flows are characterized using an extended Proper Orthogonal Decomposition (POD)-based estimation. Synchronized non-time-resolved Particle Image Velocimetry (PIV) and time-resolved, multi-point hot-wire measurements are integrated for the estimation of turbulent structures in a pipe flow at friction Reynolds numbers of 9500 and 20000. This technique enhances the temporal resolution of PIV, thus providing a time-resolved description of the dynamics of the large-scale motions. The experiments are carried out in the CICLoPE facility. A novel criterion for the statistical characterization of the large-scale motions is introduced, based on the time-resolved dynamically-estimated POD time coefficients. It is shown that high-momentum events are less persistent than low-momentum events, and tend to occur closer to the wall. These differences are further enhanced with increasing Reynolds number.
AB - Very-large-scale structures in pipe flows are characterized using an extended Proper Orthogonal Decomposition (POD)-based estimation. Synchronized non-time-resolved Particle Image Velocimetry (PIV) and time-resolved, multi-point hot-wire measurements are integrated for the estimation of turbulent structures in a pipe flow at friction Reynolds numbers of 9500 and 20000. This technique enhances the temporal resolution of PIV, thus providing a time-resolved description of the dynamics of the large-scale motions. The experiments are carried out in the CICLoPE facility. A novel criterion for the statistical characterization of the large-scale motions is introduced, based on the time-resolved dynamically-estimated POD time coefficients. It is shown that high-momentum events are less persistent than low-momentum events, and tend to occur closer to the wall. These differences are further enhanced with increasing Reynolds number.
KW - Boundary layer
KW - Pipe flow
KW - POD
KW - Very-large-scale motions
UR - http://www.scopus.com/inward/record.url?scp=85061452509&partnerID=8YFLogxK
U2 - 10.1016/j.expthermflusci.2019.02.001
DO - 10.1016/j.expthermflusci.2019.02.001
M3 - Article
AN - SCOPUS:85061452509
SN - 0894-1777
VL - 104
SP - 1
EP - 8
JO - Experimental Thermal and Fluid Science
JF - Experimental Thermal and Fluid Science
ER -