Tomo-TRPIV measurement of coherent structure spatial topology in turbulent boundary layer

作者：Jiang Nan^*; Yu Pei Ning; Guan Xin Lei

来源：Journal of Aerospace Power, 2012, 27(5): 1113-1121.

• Coherent structure
• Ejection
• Locally averaged velocity structure function
• Sweep
• Time-resolved
• Turbulent boundary layers

The spatial-temporal sequence of 3D-3C (three-dimensional-three-component) simultaneous velocity field in a turbulent boundary layer was finely measured by tomographic TRPIV (time-resolved particle image velocimetry) in a water channel. A new concept of spatial local averaged velocity structure function was introduced to describe the dilation, compression and shear distortion and rotation of multi-scale eddy structures in turbulent flow. The three fluctuating velocity components of TBL (turbulent boundary layer) were decomposed into multi-scale components by spatial local averaged velocity structure function. A new turbulence coherent structure conditional sampling method was proposed based on the dilation and compression features of turbulent multi-scale eddy structures and the new concept of spatial local averaged velocity structure function. The eject and sweep process due to large-scale coherent structure burst was conditionally detected and the characteristic spatial topology modes of physical quantities, such as velocity and vorticity, during coherent structure bursts, were extracted from the tomo-PIV (particle image velocimetry) experimental dataset. A pair of counter-wise quasi-longitudinal horseshoe shaped vortex was discovered during coherent structure eject and sweep process.

• 出版日期2012
• 单位天津大学