Numerical study on flow pass of a three-dimensional obstacle under a strong stratification condition

A three-dimensional, nonhydrostatic, numerical turbulent model was used to study the flow pass of a three-dimensional obstacle under a strong stratification condition. The numerical results clarify the behavior of the flow at a low Froude number, showing the relative importance of the stratification effects on the flow splitting wave breaking, and lee vortices phenomena. A vertical vorticity budget study shows that the tilting and friction terms are important to the formation of the lee vortices. On the other hand, the advection and stretching terms are responsible for carrying the vorticity to the lee side. The baroclinicity term can be ignored.