Large and Full-Scale Open-Jet Testing 

 

Advancing Structural Wind Engineering

In the field of aerodynamics, high-speed testing plays a critical role in evaluating the performance of structures. To overcome potential blockage effects, the open-jet concept is widely utilized. This concept is particularly suitable for large- and full-scale testing, eliminating the need for scaling requirements and enabling the determination of aerodynamic loads at high Reynolds numbers.

A groundbreaking study by Aly et al. (2022) addressed the challenges associated with building aerodynamics through extensive testing of large-scale models in the open-jet facility at Louisiana State University (LSU). The researchers thoroughly investigated velocity-related parameters and statistical quantities of roof pressures, identifying the optimal scale and testing location within the facility. To validate their findings, they compared measured surface pressures with data from Tokyo Polytechnic University's (TPU) wind tunnel and the Silsoe full-scale dataset.

By implementing the concept of flow without boundaries, the authors successfully generated both small- and large-scale turbulence. Their research showcased the open-jet facility's remarkable ability to accurately replicate mean and peak pressures on buildings, closely matching those observed in full-scale counterparts. This significant outcome not only confirms the facility's capacity to generate realistic wind loads on low-rise buildings but also paves the way for refining design guidelines and evolving code and standard provisions.

Cladding Design in High-Rise Buildings: Unveiling Higher Peak Pressures

Recent studies in aerodynamics have raised concerns that wind tunnel testing might have underestimated peak wind loads on low-rise buildings. Furthermore, the growing demand for resilient constructions capable of withstanding windstorms, driven by climate change, emphasizes the need for accurate assessments. With this in mind, our study aimed to investigate wind-induced damage to cladding in high-rise buildings, hypothesizing that wall-bounded wind tunnels underestimate the peak loads that lead to failure.

To test our hypothesis, we conducted a unique large-scale (1:50) experiment in an open-jet facility, leveraging reduced blockage effects and the ability to replicate complete velocity spectral content at high Reynolds numbers. We placed particular emphasis on comprehending the influence of aspect ratio and scale effects on pressure magnitudes and distributions. To gain deeper insights, we compared our results with data obtained from a small-scale wall-bounded wind tunnel, highlighting the significance of testing at high Reynolds numbers.

Our findings confirmed the initial hypothesis, revealing notable discrepancies in peak pressures compared to wall-bounded wind tunnel results, even though mean wind pressures on cladding and components aligned. The open jet consistently generated higher peak pressures, which concurred with real-world observations of wind-induced damage to cladding, particularly in the upper sections of buildings. Additionally, our observations indicated that aspect ratio played a crucial role in influencing both mean and peak pressure distributions on the sidewalls, further enhancing our understanding of cladding performance.
 
LSU Open Jet Wind Testing

Open-Jet Simulations: large open-jet hurricane testing facility at LSU (part of a WRW simulator).

 

 

LSU WISE Open-Jet Testing Vision: Revolutionizing Wind Engineering

The LSU WISE open-jet testing, a pioneering approach in wind engineering, promises a paradigm shift in structural resilience and design. The facility represents a Mid-Scale Research Infrastructure to address grand challenges and the need for experimental research capabilities in the mid-scale range.

LSU WISE Open-Jet Research Vision

LSU WISE open-jet testing vision: revolutionizing wind engineering to address grand challenges.

The LSU WISE open-jet facility’s unique capabilities, including complete turbulence at high Reynolds numbers, hold immense promise for revolutionizing the field of wind engineering and creating more resilient and sustainable built environments. Its potential applications span critical infrastructure such as low- and high-rise buildings, bridges, solar panels, wind turbines, nature-based solutions for coastal restoration and protection, offshore structures, and more, promising significant economic, societal, and educational impacts in science, technology, engineering, and mathematics (STEM) fields. It offers substantial educational benefits for K-12, undergraduate, and graduate students at a preeminent state university, distinguished as a land-, sea-, and space-grant institution. This initiative is poised to broadly influence wind/structural engineering research and education, fostering feasible investments within the infrastructure sector. Ultimately, this will culminate in establishing more robust and sustainable communities, promoting economic advancement, addressing grand challenges, and elevating the overall quality of life.

Selected Publications