Using the Lattice Boltzmann Method to Estimate Wind Loads on Structures

The internal and external effects of fluid flow on structures and equipment has always been a concern of designers. Since the 1970s efforts have been made to create reliable numerical methods to compute fluid flow around or through a body to supplement information gained from scale model testing. The traditional numerical approach involved solving a highly non-linear set of partial differential equations know as Navier-Stokes equations. However, an alternative approach emerged during the 1990s based on the lattice Boltzmann method. This method of modeling fluid flow has shown promising results over a broad range of fluid flow applications. This paper presents the results of simulation runs on a jack-up leg of an offshore drilling rig using the lattice Boltzmann method. The results are then compared to values obtained from wind tunnel testing. An important advantage of this alternative CFD approach is that it can simulate the actual wind velocity under full-scale conditions, thus eliminating concerns associated with Reynolds number effects in a wind tunnel.