The aerodynamic characteristics, flow fields, and flow patterns of the flow around an elliptic cylinder are investigated in this paper using large eddy simulation (LES). The Reynolds number (Re) is fixed at 16 000 in the subcritical regime, and the aspect ratio (AR) of the elliptic cylinder is varied from 0.6 to 1.4 with an increment of 0.2. The numerical model applied is initially validated for the case of AR = 1, showing good agreement with previous studies. The numerical results indicate that both the mean drag coefficient and the root mean square of lift coefficient of the elliptic cylinder decrease with increasing AR. The total drag is decomposed into two components: it indicates that the pressure drag is dominant. The primary separation point of the elliptic cylinder shifts backward with increasing AR within the range of 86.4°–92.3°. The flow fields are analyzed in detail through the time-averaged velocity profiles along three different axes. Additionally, the two-dimensional (2D) and three-dimensional (3D) visualizations of the wake patterns are also provided to show the different vortex shedding mode and the characteristics of vortex structure for different ARs. This study supplements the basic aerodynamic parameters and details of the flow around an elliptic cylinder and discusses the influence of AR at a moderate Re in the subcritical regime and has a certain significance for further optimization of the simplified model of the human body for efficient aerodynamic testing of sport garments.

From the point of view of wind engineering, this paper discusses the wind characteristics of China's south-eastern coast area near the ground based on field measurements. Five three-dimensional (3D) ultrasonic anemometers were installed at different heights on a transmission tower in Xiupu, Fujian province, which is a typical coastal landform in South-east China. These anemometers synchronously collected wind records. The wind data were sorted according to the strong wind criterion. The exponent of the mean wind speed and the turbulence intensity profile are provided based on the power law, and suggestions for code are given. The aerodynamic parameters of turbulence in the atmospheric boundary layer are given and used to evaluate the existing empirical models of 3D fluctuating wind speed, such as turbulence intensity, gust factor, turbulence integral length scale and power spectral densities. The provided results can be used by designers to improve the wind resistance of civil engineering projects in South-east China.

Providing an opening in a beam web (OBW) is a possible approach to improving the aseismic behaviour in beam-to-column connections in steel moment frames. The finite element analysis in this paper shows that the behaviour of the OBW connection depends on a size of the opening, R, and the opening location, b. When parameters are properly selected, Vierendeel hinges form in the weakened areas resulting in a beam with high ductility. Quasi-static tests were carried out based on the finite element analysis results. The test results showed that Vierendeel hinges formed in the weakened areas and brittle weld fracture was avoided in the OBW connections. The performance indicators of the OBW connection are not reduced with a weakened section. Aseismic behaviour of the beam-to-column connections are improved with an opening in the beam web. To explain the failure mechanism of the OBW connection, the stress distribution obtained from the finite element analysis was studied. The stress distribution around the opening was found dramatically changed because of the provision of the opening. Four plastic zones formed in the web around the opening under the interaction of normal and shear stresses at the critical locations resulting in ductile Vierendeel hinges.

The low-aspect-ratio cylindrical structures represented by oil tanks is a kind of wind sensitive structure, which is prone to buckling under wind-loads. A wind tunnel test was conducted to investigate the properties of wind-loads acting on smooth cylinders with an aspect ratio AR = 0.323 and 0.875, respectively. Some parameters, such as Reynolds number (Re) and turbulence intensity, were taken into account. The results reveal that low-aspect-ratio cylinders have a Re effect, and the effect rises with AR. AR is the main factor affecting the value of the base pressure coefficient and positive pressure range, and the former increases with AR, while the latter decreases with AR. Moreover, due to the influence of the free end and turbulence, which may suppress vortex shedding, the power spectrum of the lift coefficient essentially shows broad spectral peaks with Re and turbulence. Increasing the incoming turbulence made the flow round cylinders at a higher Re state, that is, the supercritical regime is reached at a smaller Re. When turbulence is greater than 4.0%, turbulence and Re have little effect on the mean base force coefficient of low-aspect-ratio cylinders.