Open-jet testing: Investigating turbulence and geometric scale effects on surface pressures in the atmospheric boundary layer

Bluff body aerodynamics is essential for the design and safety of structures exposed to wind forces. Traditional atmospheric boundary layer wind testing often fails to replicate the complex turbulence characteristics of real-world flows, necessitating innovative testing methodologies. We developed an open-jet testing approach and conducted experiments on scaled models (1:7.6 and 1:10) at Reynolds numbers ranging from 0.5 × 106 to 1 × 106, significantly higher than those typically achieved in conventional testing. This methodology produced integral length scales approximately ten times larger than those observed in traditional methods, resulting in 25%–300% higher peak pressures than those from small-scale tests, closely aligning with full-scale field data. Our findings emphasize the necessity of testing under complete atmospheric boundary layer turbulence to ensure accurate wind pressure predictions. Insights into the effects of advanced flow on separation, reattachment, and pressure distribution inform new experimental protocols and have significant implications for the design and safety of structures in wind-prone regions. By establishing a robust benchmark for future experimental and computational simulations in wind engineering, this approach promotes the development of safer, more resilient, and economically viable building designs capable of withstanding extreme wind events exacerbated by climate change, contributing to sustainable infrastructure advancement.