Downbursts are extremely spontaneous and dangerous phenomena that have been shown to be responsible for failures of many structural systems. The Wall of Wind team is currently in the process of developing a large-scale downburst simulator that could facilitate research to improve the resistance of building envelopes and lifeline infrastructures. For this purpose, four setups have been numerically simulated in order to recreate downburst-like wind characteristics while the height of the maximum velocity can be controlled. Consequently, three different roughness elements have been added, and the results demonstrate that the roughness elements have a positive impact on the height of the maximum velocities.