A Modified Inflow Turbulence Synthesis Method for Large Eddy Simulation: Application to Thermal Stratification Effects on Wind Loads of an Isolated Cubic Building

The variation in thermal stratifications significantly alter the distribution of the wind load on buildings. In this study, large eddy simulation (LES) was adopted to investigate this influence on an isolated cubic building. The thermally stratified turbulent inflow for LES was synthesized by a modified generation method, which combines equilibrium boundary conditions with empirical stability functions and integrates them into the Fluent inherent vortex method. The effectiveness of the present method was verified by comparison with corresponding wind tunnel test data under neutral stratification. The simulated wind load around an isolated cubic building was then compared across three thermal stratification conditions, including neutral, stable and unstable stratification. Compared with the neutral stratification, variations in temperature result in variations in the position and morphology of the horseshoe vortex location at the windward side and separation vortex at the top under stable and unstable stratifications, changing the distribution characteristics of wind pressure in those areas. On the leeward side, the wind pressure and its non-Gaussian characteristics under stable and unstable stratifications are enhanced due the variation in temperature. The extreme wind pressure coefficient at the bottom region of the leeward surfaces under the stable and unstable stratification increases by 1.38- and 1.50-fold, respectively.