Atmospheric boundary layer simulation in a new open-jet facility at LSU: CFD and experimental investigations

Aly, Aly Mousaad; Gol-Zaroudi, Hamzeh

doi:10.1016/j.measurement.2017.06.027

Cited by 18 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Wind tunnel testing of section models is usually conducted for long-span structures, such as bridges, to allow for larger geometric scales [42]. Accordingly, experimental investigations were conducted at the LSU open-jet that was already calibrated against wind tunnel measurements, in separate research studies [43,44]. The flow characteristics of this wind simulator are available in previous publications [41,43,44].…”

Section: Experimental Investigationsmentioning

confidence: 99%

“…Accordingly, experimental investigations were conducted at the LSU open-jet that was already calibrated against wind tunnel measurements, in separate research studies [43,44]. The flow characteristics of this wind simulator are available in previous publications [41,43,44]. Figure 6 presents the details of the experimental setup.…”

Section: Experimental Investigationsmentioning

confidence: 99%

See 1 more Smart Citation

A Framework for Vibration Attenuation in Traffic Mast Arm Structures under Wind Loads

2021

View full text Add to dashboard Cite

Traffic signals and information signs play a vivid role in maintaining safe travel by guiding drivers on highways and urban roads. Traffic mast arm structures are susceptible to vibrations induced by wind loads. Fatigue-induced failure is common in these structures. However, it is crucial to ascertain the functionality of signal support structures. This paper lays the foundation for a fully computational framework to model and mitigate wind-induced vibrations in traffic lighting support structures by conducting computational fluid dynamics (CFD) simulations, dynamic modeling, and damping enhancement. We validated the CFD simulations by aerodynamic testing. The dependence of flow pattern and aerodynamic loads on Reynolds number reveals the importance of full-scale CFD with large eddy simulation for wind load estimation on mast arm structures. Distributed tuned mass dampers were created by employing available weights of lighting boxes. The results show that distributed tuned lighting boxes are effective for vibration suppression. Besides, damping enhancement can significantly reduce vibration-induced stresses and hence extend the fatigue life. The proposed mitigation technique promises to save construction costs and improve the safety of the traveling public. The procedure followed for creating time histories of wind loads integrated with finite element modeling applies to other vibration lessening techniques for potential inclusion in the AASHTO standard.

show abstract

Section: Experimental Investigationsmentioning

confidence: 99%

Section: Experimental Investigationsmentioning

confidence: 99%

A Framework for Vibration Attenuation in Traffic Mast Arm Structures under Wind Loads

2021

View full text Add to dashboard Cite

show abstract

“…The size of the wind tunnel was held responsible for mismatch in the low-frequency end of the spectrum. High-frequency vortices are responsible for creating the flow pattern around bluff bodies, whereas low-frequency large eddies have higher influence on aerodynamic peak loads [63]. To conclude, in the case of low-rise buildings, it has been always a challenge, in wind tunnel testing, to properly simulate wind effects due to the lack of capability in turbulence modeling [56].…”

Section: Wind Tunnel Testingmentioning

confidence: 99%

“…This said, scaling residential homes is essential to maintain correct physics, and at the same time large-scale testing (not full-scale) will lead to improved Reynolds number. Large-scale wind testing went through several phases before reaching the present stage [63]. A multidisciplinary LSU research team from Civil and Environmental Engineering, Mechanical Engineering, Coast and Environment, Louisiana Sea Grant, Geography and Anthropology, Construction Management, and Sociology collaborated on a project titled "Hurricane Flow Generation at High Reynolds Number for Testing Energy and Coastal Infrastructure" that was awarded by the Louisiana Board of Regents to build Phase 1 of a large wind and rain testing facility (Figure 10).…”

Section: Open-jet Testingmentioning

confidence: 99%

Aerodynamics of Low-Rise Buildings: Challenges and Recent Advances in Experimental and Computational Methods

Aly¹,

Khaled²,

Gol-Zaroudi³

2021

Aerodynamics

Self Cite

View full text Add to dashboard Cite

Buildings are bluff bodies, compared to streamline objects, such as airfoil. Wind flow over buildings leads to separation and hence a complex spatial and temporal mechanism that governs the nature and intensity of aerodynamic forces. This complexity mainly comes from the transient nature of incident turbulent winds and the fluctuating flow pattern in the separation bubble. The study of building aerodynamics is vital for the evaluation of cladding pressures, drag, shear, and uplift forces that are essential for safe and economic design. Flow separation makes it challenging to estimate loads without referring to direct physical and/or computational simulation. For several decades, aerodynamic testing has been employed for the estimation of wind pressures and forces on buildings. However, for residential homes and low-rise buildings, it has been always a challenge to predict full-scale pressures by traditional wind tunnel testing, as per the lack of large turbulence and Reynolds number effects, among other factors. The mismatch in flow physics makes it difficult to scale up wind-induced loads as the process can be highly nonlinear, which is the case when full-scale pressure coefficients do not meet those from small-scale aerodynamic testing. This chapter presents the challenges in the modeling and evaluation of aerodynamic forces on low-rise buildings, along with recent advances in both experimental and computational methods.

show abstract

“…For example, Computational Fluid Dynamics (CFD) methodologies were used to improve the ABL generation and to design an optimized setup for an open-jet facility. 10 Comparative studies between tunnel tests and numerical simulations were also useful for a proper and optimal design of new tunnels. 8 The aim of this study is (i) to describe the average and turbulent flow in an open-circuit boundary layer wind tunnel, (ii) to compare the performances with those of a closed-circuit wind tunnel, which has a similar geometry of the test section and to analyze the differences between them, and (iii) to highlight critical issues that may be common to tunnels of the same type, providing data and ideas useful for the management and the improvement of these facilities.…”

Section: Introductionmentioning

confidence: 99%

Air flow quality analysis of an open-circuit boundary layer wind tunnel and comparison with a closed-circuit wind tunnel

et al. 2020

View full text Add to dashboard Cite

The wide use of wind tunnels, as a tool to measure the flow properties and the flow effects on different structures/ecosystems, makes it necessary to guarantee the correct functioning of the facility and to carry out a continuous monitoring. The aim of this work is (i) to check the homogeneity and quality of the air flow in an open-circuit boundary layer wind tunnel, (ii) to provide data and ideas that could help other researchers to improve similar tunnels, and (iii) to compare some of the results with the behavior of a classic closed-circuit wind tunnel. Experiments are carried out working with a constant reference velocity, using a hot cross wire anemometry system to obtain high resolution measurements, in the entrance and test sections for different longitudinal and cross planes. The results concern the characteristics of the mean and turbulent flow. In this manuscript, we report the analysis of the turbulence production, the Reynolds stresses, the vertical velocity skewness, the vorticity, and the spectral properties, and a quadrant decomposition is also performed. Finally, comparing the results with respect to a closed-circuit wind tunnel, it is shown that the turbulence intensity is generally higher and the mean flow is more homogeneous in the present open-circuit wind tunnel. Moreover, the Reynolds number is similar in both tunnels, which indicates that both tunnels are mechanically similar.

show abstract

Atmospheric boundary layer simulation in a new open-jet facility at LSU: CFD and experimental investigations

Cited by 18 publications

References 25 publications

A Framework for Vibration Attenuation in Traffic Mast Arm Structures under Wind Loads

A Framework for Vibration Attenuation in Traffic Mast Arm Structures under Wind Loads

Aerodynamics of Low-Rise Buildings: Challenges and Recent Advances in Experimental and Computational Methods

Air flow quality analysis of an open-circuit boundary layer wind tunnel and comparison with a closed-circuit wind tunnel

Contact Info

Product

Resources

About