سال انتشار: ۱۳۸۵
محل انتشار: هفتمین کنگره بین المللی مهندسی عمران
تعداد صفحات: ۱۰
sara Hormozi – MSc Student
Bahar Firoozabadi – Assistant professor
Hamed Ghasvari jahromi – MSc Student
Density current is a dense fluid, which is continuously released from a source and spreads down a sloping surface inside a lighter , motionless fluid. Associate CFD code has been written to describe salt solution density current, which propagates three-dimensionallu in deep ambient water. The equations of continuity , momentum conservation, and diffusion are solved simultaneously in the fixed Cartesian directions, on a non-staggered grid using finite volume scheme. The velocity-pressure coupling is handled by SIMPLEC method. Comparison of the computed velocity and concentration of the density currents with the experimental data shows a good agreement between them. Analysis indicates that the dense layer spreads in all directions at a rare proportional to the entrainment coefficient. Then it approaches a normal state after release and the flow behaves as 2-Department . Depth – averaged parameters were calculated to obtain entrainment coefficient. The results showed that entrainment coefficient decreases when Richardson number increases. This result has the same trend as Ellison and Turner  experimental data. The present model provides a physical understanding of such complex phenomena.