1. Beijing University of Aeronautics and Astronautics, Beijing 100083, China
2. Laboratory for Nonlinear Mechanics of Continuous Media, Institute of Mechanics, CAS, Beijing 100080, China
Funding project: 国家自然科学基金资助项目(10172016);国家重点研究发展规划资助项目(1999022305);国家自然科学基金重点基金资助项目(50136010)
Received: 2003-08-01
Revised: 2003-08-07
Available online: 2003-11-20
Abstract
The evolution of coherent structures in the wall region of a turbulent boundary layer under adverse pressure gradients was studied by using DNS method. The motions of the second and the fourth quadrant were analyzed. The results show that to the shear stress, the contribution of sweep motions is stronger than that of ejections under adverse pressure gradient. And the sweeps contribute to the transport of shear-stress and kinetic energy of turbulence more strongly than the ejections under adverse pressure gradient.