The Alcantara Launch Center (ALC) is the main Brazilian access to space. It is positioned over a complex terrain, and it has some important buildings for assembling, integration and launching activities, such as the Mobile Integration Tower. Being in a region of prevalent trade winds, the flow interaction between the complex terrain and the buildings can affect the safety of operations on the platform, and the dispersion of toxic gases emitted during the launching. The main objective of this work was to study the influence of topography and buildings on the atmospheric flow of ALC using computational fluid dynamics (CFD) techniques. Three geometries were considered: simplified terrain (case 1), smooth complex terrain (case 2), and roughness complex terrain (case 3). The flow conditions over ALC were simulated using the ANSYS Fluent 19.0 CFD commercial code. The numerical simulations used a realizable κ-ε to model turbulence effects and the results presented a good agreement with the in-situ field measurements for the most complex geometry (case 3). The topography clearly influences the flow pattern at ALC, with the cliff influence over the wind being the major cause for establishing the flow patterns.

The atmospheric flow at Alcântara Launch Center (CLA) was studied using Computational Fluid Dynamics (CFD) techniques. To characterize the region were considered the coastal cliff and the Integration Mobile Tower, called TMI, both within the launching and preparation area (SPL). In this study, the cliff was represented by a step of 90° with 40 meters of height. The inlet velocity profile was elaborate according to the power law, with exponent of 0.11, freestream velocity of 20 m/s and Reynolds number of 4.3 x 105, adopting neutral atmosphere. Three wind directions were considered, 90º, 125º and 135°. The numerical model used was the Reynolds Stress Model (RSM), based on the Reynolds-Averaged Navier-Stokes (RANS) equations. The solution of the equations was obtained by ANSYS FLUENT 19, which uses the finite volume method. The results showed good agreement with the wind tunnel tests especially for wind direction perpendicular to the cliff. The incident wind direction strongly influences the flow dynamics in the SPL forming a helicoidal vortex over the coastal cliff the higher the wind slope.