Buildings and structures in the atmosphere experience the pressure and force that natural wind exerts on them, referred to as the wind loads. Over the past decades, the progress of the wind load related studies for high-rise buildings has been accelerated using the technique of computational fluid dynamics (CFD). CFD draws its strength from providing more comprehensive information and being more capable of controlling oncoming wind flow characteristics than conventional wind tunnel test. However, due to the complexity of the atmospheric boundary layer (ABL) wind characteristics and intricacy of bluff body flows, the wind effects on high-rise buildings have not been fully understood. Therefore, this thesis aims to use CFD simulation to further the understanding of the ABL characteristics and wind loads on high-rise buildings. The major content of this thesis is divided into three parts.

In the first part, the Coriolis effect, a wind phenomenon caused by the earth rotation, on the ABL wind characteristics is firstly investigated. Thousand-meter high ABLs with and without considering the Coriolis effect over typical terrain types are modelled by large eddy simulation (LES). The simulated wind profiles are compared to isolate the influence of the Coriolis effect on the wind characteristics, including the mean wind speed, turbulence intensity, and turbulence integral length scale. Next, the Coriolis effect on the mean and fluctuating wind pressures and forces on high-rise buildings is simulated by LES based on three-dimensional (3D) square prism models. The mechanism of the Coriolis effect on the wind loads is explained by the proper orthogonal decomposition (POD) method. The influence of the Coriolis effect on the wind loads for different building heights and wind directions is quantified.

In the second part, the wind loads on an unconventional-shaped supertall high-rise building in real urban environment are simulated by LES. The simulated results are compared with a previous wind tunnel test and a field measurement during a super typhoon to evaluate the reliability and accuracy of CFD as a stand-alone tool for wind-resistant design. First, a reduced-scale LES is conducted for the target high-rise building and validated by the wind tunnel test. The aerodynamic characteristics of the target building obtained from the LES and wind tunnel test at various wind directions are compared and analysed, including the wind pressure and force coefficients, wind force spectra, base moments, and wind force correlations. Second, a full-scale LES for the target high-rise building is conducted and validated by the field measurement under Super Typhoon Mangkhut. A wide range of surrounding buildings near the target supertall building (within a radius of 5 km from the target building) are explicitly constructed for the simulation. The wind profiles obtained from a 356-m-high meteorological tower in Shenzhen and those given in the local design load code are used to set the inflow conditions in the LES. The wind pressures on the target building simulated by the LES and monitored by the field measurements are compared and analysed, including their mean, root mean square, and peak values, as well as their probability density functions, power spectral densities, and correlations.

The third part uses fluid-solid interaction (FSI) simulation to investigate the unsteady effect of oncoming wind flow on bluff body’s aerodynamic characteristics and aeroelastic responses. This part first investigates the wind-induced vibration of a 3D aeroelastic square prism model in sinusoidal oscillatory flows (SOFs). A homemade FSI solver to conduct FSI simulation is developed, and its reliability is validated by wind tunnel test. The wind forces on and wind-induced displacements of the model in SOFs with different amplitudes and frequencies are simulated. The mean and instantaneous wind fields around the aeroelastic model are presented, and the wake characteristics of the model are analysed by dynamic mode decomposition. Next, FSI simulations are conducted for the square prism model in turbulent flows with different turbulence integral length scales. The influences of the longitudinal and lateral turbulence integral length scales on the mean and fluctuating wind pressures and forces, wind pressure correlations, shear layer behaviours, and model displacements are separately investigated. The Reynolds stresses of the flow field around the model are analysed. The outcomes of this thesis are expected to be a valuable reference for wind-resistant design of high-rise buildings and promote the development of structural computational wind engineering.