Numerical Study for Boundary-Layer Flow Past a Full 3D Obstacle

This paper presents a scenario study towards building a simulation of high Reynolds number fluid flow passing a 3D obstacle with the aim of understanding the airflow structures involved as the obstacle gets steeper. The motivation for the development of this simulation originates from the study of atmospheric boundary layer flow around a tall building. A numerical result is obtained by taking into account the atmosphere boundary layer using reduced Navier-Stokes equations. Two general shapes of distribution of skin-friction are studied, (i) smooth edges and rounded top and (ii) smooth edges with flat top. Our results show that in order to get the numerical result, there must be a restriction on the size of the obstacle with certain critical height for flow separation; the critical height for separation is found to be related to the edge lengthscale. Also, the flow reattachment point is noticed after the flow separates.