Project supported by the Science and Technology Research Projects of Shandong Province(Grant No.2008GG10007009);the National Key Basic Research Development Program of China(973 Program,Grant No.2007CB206903)
The characteristics of the longitudinal vortex induced by trapezoid-winglets in a circular tube are investigated by the Particle Image Velocimetry (PIV) Technique with flow Reynolds number in the range of 500-13 000...
By considering that the coherent structure is the main cause of the Reynoldsstress, a new Reynolds stress expression was given. On this basis the velocity distribution in thetrapczoid-seclion open channel flow was wor...