Advancing Partial Turbulence Simulation for Wind-Resilient Envelope Systems, Exterior Attachments, and Small Structures

Community resilience to wind hazards requires reliable load estimates for building envelope systems, exterior attachments, and small structures. Post-storm investigations document widespread failures of envelope systems and attachments on low-rise buildings below design wind speeds. Envelope breaches admit wind-driven rain and cause cascading interior damage, while failures of rooftop equipment, solar arrays, and other exposed systems disrupt operations and delay recovery. Most boundary-layer wind tunnels were configured around small models of large, complex engineered structures. Yet widespread damage often begins with smaller, less costly systems requiring larger, more detailed models. This mismatch leaves many systems dependent on simplified product tests that cannot recreate localized, rapidly fluctuating pressures. Partial Turbulence Simulation offers a way around this obstacle through a controlled simplification of the modeled flow, allowing existing tunnels to estimate these loads more realistically. Supported by theory and prior validation, the method requires rigorous definition of its strengths, limits, and appropriate applications. The project will establish that framework to support reliable load estimates, improved testing and design, and greater wind resilience. It will also produce open benchmark data and project-based educational opportunities focused on wind hazards. Partial Turbulence Simulation expands usable model scales by partitioning turbulence according to how it interacts with separated flow. Larger, slower eddies are treated as quasi-steady changes in wind speed and direction, while smaller, faster eddies are reproduced physically and interact directly with flow dynamics. This controlled partition enables larger models but depends on identifying the spectral range over which quasi-steady reconstruction remains valid. The central hypothesis is that an appropriate partition preserves the mechanisms producing design-relevant fluctuating and peak loads. The research will determine when quasi-steady reconstruction begins to alter those mechanisms or distort the resulting loads. The experiments use a facility uniquely suited to this question. Its multi-fan turbulence generator and automated roughness system can produce combinations of turbulence scale, intensity, and spectral distribution unavailable in conventional wind tunnels. This enables direct comparison between near-prototype reference flows and partitioned cases. Pressure measurements and particle image velocimetry will characterize loading and separated-flow dynamics across canonical and representative low-rise geometries. The project will establish when Partial Turbulence Simulation can be trusted and translate that understanding into more reliable wind-tunnel testing and wind-load design. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.