TY - GEN

T1 - Extraction of multi-scale vortical structures from a homogeneous isotropic turbulence

AU - Kareem, Waleed Abdel

AU - Izawa, Seiichiro

AU - Xiong, Ao Kui

AU - Fukunishi, Yu

PY - 2008/12/1

Y1 - 2008/12/1

N2 - An attempt to extract multi-scaled vortical structures from a turbulent field is carried out. The Lattice Boltzmann method with forcing is used to generate a statistically stationary velocity field in a resolution of 256 3. Two methods for filtering, namely the Fourier and wavelet decompositions, are used in the investigation and the results are compared. Three fields that contain vortical structures of different-scales area extracted from the original turbulent field. It is found that the results obtained by the two methods overlap at a high rate. Several universal characteristics among the filtered flow fields are found in the comparisons using the invariants of the velocity gradient, rotation and deformation tensors.

AB - An attempt to extract multi-scaled vortical structures from a turbulent field is carried out. The Lattice Boltzmann method with forcing is used to generate a statistically stationary velocity field in a resolution of 256 3. Two methods for filtering, namely the Fourier and wavelet decompositions, are used in the investigation and the results are compared. Three fields that contain vortical structures of different-scales area extracted from the original turbulent field. It is found that the results obtained by the two methods overlap at a high rate. Several universal characteristics among the filtered flow fields are found in the comparisons using the invariants of the velocity gradient, rotation and deformation tensors.

KW - Fourier filter

KW - Lattice Boltzmann method

KW - Multi-scaled vortices

KW - Velocity gradient analysis

KW - Wavelet filter

UR - http://www.scopus.com/inward/record.url?scp=84861114651&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861114651&partnerID=8YFLogxK

U2 - 10.1007/978-1-4020-6472-2_22

DO - 10.1007/978-1-4020-6472-2_22

M3 - Conference contribution

AN - SCOPUS:84861114651

SN - 9781402064715

T3 - Solid Mechanics and its Applications

SP - 143

EP - 148

BT - IUTAM Symposium on Computational Physics and New Perspectives in Turbulence - Proceedings of the IUTAM Symposium on Computational Physics and New Perspectives in Turbulence

T2 - IUTAM Symposium on Computational Physics and New Perspectives in Turbulence

Y2 - 11 September 2006 through 14 September 2006

ER -