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Cladding damage of tall buildings often occurs during hurricane events, and the damage is not only costly but also impacts the economy, and more importantly, threatens lives. One solution to reduce the cladding pressure is the application of modified double-skin facade (DSF) which is already of great interest to architects due to improving building energy efficiency. This paper investigates the effects on the cladding pressures of a building fitted with a DSF with vertical openings in the external skin mounted in front of the windward face of the building. The effects of the vertical openings on the building's surface pressure were investigated by conducting pressure measurements in the wind tunnel. The associated flow mechanisms were revealed by using particle image velocimetry technique. The DSF without opening increases both the mean suctions and fluctuating pressures on both side and leeward faces, and hence this common facade configuration leads to an undesirable effect on building claddings under strong winds. In contrast, the DSF with the opening(s) can effectively reduce wind pressures on the side and leeward faces. Therefore, creating vertical openings on the external skin of DSF is a practical approach to enhance the wind-resistance performance of building claddings.

This study investigated mean flow characteristics and structure of flow inside through-building openings with five different layout configurations for the purpose of wind energy harvesting. Two-dimensional Particle Image Velocimetry (PIV) was employed and validated against a series of Cobra probe measurements. The mean flow characteristics including streamwise and vertical mean velocity were investigated at the wind direction parallel to the corridors of the through-building openings. The coherent structure of flow was studied, using two-point cross-correlation and a simple flow visualisation. The results showed that creating recessed regions at inlet and outlet of the openings and using curved walls at corners increase the mean velocity at the middle of the corridor by approximately 25%. When using converging-diverging passages for openings, the mean velocity increases by approximately 33%. The two configurations exhibit better performance in attuning the flow to be more inform and steady in a larger portion of the corridor, and hence these configurations have the capacity to enhance the performance of a potential wind turbine inside the corridor. The confined area of corridors contributes to the progressive reduction of undesirable characteristics of the cavity flow including vertical mean velocity, and streamwise and vertical velocity fluctuations along the corridor.

The increasing global concern about climate change and energy crisis has necessitated the development of techniques to reach and exploit renewable energy in unexplored regions. As such, decentralized small-scale wind energy harvesting in urban environments has gained momentum in recent years. In this study, a methodology has been developed to assess the performance of a special Double Skin Facade (DSF) system for wind energy generation using CFD simulations and local wind data. As a case study, a story-high corridor-type DSF system equipped with an array of wind turbines was integrated into a high-rise building, and its Annual Energy Production (AEP) within the context of four Australian cities was evaluated. The results showed that the free-stream wind speed can be amplified up to a maximum of 1.8 times inside the corridors of the DSF system. It was concluded that the benefit of the DSF system can be exploited the most in cities with strong bi-directional wind characteristics. Finally, it was shown that wind turbines inside the DSF system can annually generate up to 50% more energy at open terrain and 22%–45% more energy at dense urban and suburban terrains as compared with the same turbines in the free-stream condition.

To maximise the potential of decentralized micro-grid wind energy generation in urban environments, it is vital to develop techniques to enhance the flow characteristics in urban environments. This paper reports on an investigation of a new method of exploiting wind energy by utilizing a modified innovative Double Skin Facade (DSF) system. Computational Fluid Dynamics (CFD) simulation has been employed to investigate the effect of aerodynamic modifications, including recessed regions and curved walls, on the flow characteristics inside an empty corridor-type DSF for different wind directions. CFD results were validated against a series of wind tunnel tests. The results indicate that, compared with the original DSF, the modifications are capable of significantly enhancing the flow velocity inside the DSF at all wind directions, especially when the direction of the upstream wind aligns with the flow direction inside the DSF. The results also show the contribution of the confined area in diminishing the variations in velocity and reducing turbulence by a maximum of about 30%. It is concluded that the average available wind power density of an empty corridor-type DSF can be increased by a factor of 2 and 4.2, respectively, by creating recessed regions and curved walls.

To date the engineering community has seen double-skin facade systems as non-structural elements on buildings for the aesthetic desire, improving the indoor environment, reducing the energy use, and even improving acoustics in buildings. In this study, the effects of a double-skin facade system on the wind-induced responses of a tall building were investigated via a program of wind tunnel tests. Two types of wind tunnel tests, i.e. aeroelastic test and pressure test, were performed. It was found that a double-skin facade with/without vertical openings installed in front of the windward face of the building model results in very different effects on the wind-induced responses in alongwind and crosswind directions. In the alongwind direction, the facade with/without openings induces negligible effects on the wind-induced response. However, in the crosswind direction, the facade with opening(s) reduces the wind-induced response significantly, whereas the facade without any opening increases the response, compared to the bare tall building model. Therefore, in addition to achieve the purposes of the aesthetic desire, improving indoor environment and reducing energy use, the double-skin facade system with vertical opening(s) can also be used to effectively reduce crosswind responses without inducing larger alongwind responses.

Efficient wind energy harvesting by utilizing small-scale wind turbines in the urban environment requires techniques to enhance the desirable flow characteristics, including velocity magnitude and uniformity, and diminish the unfavorable characteristics, including high turbulence and intermittence. This study proposed a Double-Skin Facade (DSF) system with strategic openings to harvest wind energy in the built environment. A series of wind tunnel tests and CFD simulations have been conducted to investigate the characteristics and related mechanisms of flow within the cavity of DSF integrated with a tall building model at different incident wind angles. The discrepancy between numerical and experimental results generally remains within an acceptable range of 15% which validates the capability and accuracy of the developed CFD simulations in predicting the flow characteristics. It was found that the flow becomes more uniform while the turbulence progressively decays as flow progresses through the cavity for all wind directions. Hence the regions in the middle of both the leading and trailing sides of the cavity are favorable locations for installing small-scale, building-mounted wind turbines. Overall, the DSF system with a strategic opening can effectively enhance the flow within the cavity for a wide range of incident wind angles and can be adapted for wind energy harvesting purposes.

Insufficient airflow in the cavity of Double Skin facade (DSF) systems has resulted in the overheating risk of the cavity and the resulting reduction in thermal performance in cooling dominant climates. Previous research has focused more on buoyancy-driven natural ventilation, and there is a lack of research on utilising wind-driven ventilation in the cavity as a dominant natural force for the heat dispersion from the cavity. Additionally, geometrical features of the cavity and wind direction as influential factors on wind-induced airflow have not been addressed in DSF studies. This paper presents a detailed evaluation of the impact of opening configurations on the ventilation performance of an integrated tall building with DSF with respect to four wind orientations (0°, 30°, 60°, and 90°) to the facade. The evaluation is based on three ventilation performance indicators: (i) induced airflow rate, (ii) wind speed ratio, and (iii) airflow distribution across the cavity length. High-resolution 3D steady RANS CFD simulations of cavity ventilation were performed for a range of sizes of the DSF cavity. The CFD simulations were validated against wind-tunnel measurements. The results show that the ratio between the areas of the front and lateral openings is a critical factor for improving the ventilation in the cavity at the wind incident angle 0°

In the present study, the buckling of laminated composite curved panels embedded with Shape Memory Alloy (SMA) fibers under different geometrical conditions was studied. The buckling load of curved panels subjected to axial, lateral and mixed loads was analyzed. Different distributions of SMA fibers were considered. The optimized reinforcement of curved panel using SMA fibers based on different opening angles was studied. The sensitivity analysis was performed to investigate the effect of the variables of fiber distribution function on critical buckling load of the panel. The results indicate that by increasing the radius, the buckling load for both axial and lateral loadings decreases, while the share of SMA fibers on buckling load increases. The result shows the possibility of buckling load enhancement by optimized distribution of SMA fibers in both flat and curved panels. In addition, sensitivity analysis shows that critical buckling is very sensitive to the coefficient of higher non-uniform distributions.