Performance Comparison of Different Building Shapes Using a Wind Tunnel and a Computational Model

Simulation and Optimization Study on the Ventilation Performance of High-Rise Buildings Inspired by the White Termite Mound Chamber Structure

High-rise buildings often use mechanical systems to assist ventilation to maintain the stability of their internal environments, and the energy consumption of mechanical ventilation poses a great challenge to urban environments and energy systems. The ventilation system of termite mounds with a combination of internal main and attached chambers is one of the classic examples of nature's bionic approach to maintaining a stable internal ventilation environment for large-volume structures. In this study, based on the inspiration of the internal ventilation chamber structure of bionic termite mounds, we constructed seven high-rise building chamber ventilation models based on the chamber structure of termite mounds with main chambers, main chambers plus single-attached chambers (three types), and main chambers plus double-attached chambers (three types) under natural ventilation conditions, aiming at obtaining the optimal low-energy and high-efficiency chamber ventilation model for bionic termite mounds in high-rise buildings. (1) The wind speed and wind pressure of the high-rise building with the addition of the bionic termite mound chamber structure is higher than that of the traditional chamber-free high-rise building in the sample floors, the maximal difference of the wind speed between the two models is 0.05 m/s, and the maximal difference of the wind speed of the single building is 0.14 m/s, with the maximal difference of the wind speed of the single building being 0.14 m/s; and the natural ventilation environment can be satisfied by a high-rise building with a chamber. (2) After increasing the single-attached chamber structure of the bionic termite mound, the difference in wind speed of different floors is 0.15 m/s, which is 0.10 m/s higher than that of the high-rise building model with the main chamber only. (3) Under the bionic termite mound chamber high-rise building double-attached chamber model, the maximum difference in wind speed of each floor sampling point can reach 0.19 m/s, while the wind pressure cloud map shows a stable wind environment system. (4) Two attached chambers are added at A and B of the high-rise building to form the a4 model of the chamber of the high-rise building with a double-chamber bionic termite mound. According to the results, it can be seen that the model of the nine floor sampling points of the maximum wind speed difference has six places for the highest value, and the single building wind speed difference for the minimum value of 0.10 m/s. The study aims to optimize the connectivity and ventilation performance of high-rise buildings under natural ventilation conditions and to promote the green and sustainable design of high-rise buildings.

Coupling CFD Simulation and Field Experiments in Summer to Prove Feng Shui Optimizes Courtyard Wind Environments: A Case Study of Prince Kung’s Mansion in Beijing

Feng shui in ancient China was harmonized with the natural environment. The layout of houses following feng shui is conducive to a comfortable wind environment. To explore the positive influence of feng shui on ventilation, this study takes Prince Kung’s Mansion, which has the characteristics of a feng shui layout, as the research object. In parallel, the study assumes a dissimilation layout that has lost the feng shui layout characteristics. Comparing the ventilation of courtyards in the summer for both the feng shui layout and the dissimilation layout through CFD simulation, the results were as follows: (1) the wind speed values in the summer, taken from 60 points in Prince Kung’s Mansion by way of CFD simulation and field experiments, were well coupled, which proves that PHOENICS is suitable for the courtyard wind environments simulation in this study. (2) The CFD simulation results show that the average wind speed and the comfortable wind speed zone ratio in the courtyards of the feng shui layout were higher than those of the dissimilation layout during the summer, and the courtyard wind speeds of the two layouts were linearly related. Therefore, the feng shui layout is more conducive to the comfort of courtyards’ wind environment than the dissimilation layout. (3) The front and rear wind pressure differences of the main houses in the feng shui layout can optimize the indoor ventilation better than those of dissimilation layout in the summer. (4) According to the evaluation criteria for the wind environment, the wind speed and wind pressure of the feng shui layout are superior to those of dissimilation layout in the summer. In summary, this study verifies that the layout of feng shui optimizes the courtyard wind environment in the summer, which embodies the ecological concept of the Chinese ancients in the layout of houses.

Research on Equivalent Static Load of High-Rise/Towering Structures Based on Wind-Induced Responses

A method of assessing equivalent static wind loads that can represent all the real ultimate states of a high-rise building and towering structure has still not been fully determined in wind engineering. Based on random vibration theory, the wind-induced response and equivalent static wind loading of high-rise buildings and towering structures are investigated using the vibration decomposition method. Firstly, the structural wind-induced mean response, background response, resonant response and background and resonant coupled response are studied in the time and frequency domains. Secondly, a new gust load factor (GLF) assessment method suitable for wind-induced displacement, bending moment and shear force response at any height of the structure is proposed, and a typical high-rise building is used as an example for comparison with the previous research results, in order to verify the effectiveness of the method in this paper. The results show the following: for high-rise buildings and towering structures, the percentage of the coupled components in the total pulsation response is less than 2%, and the influence can be ignored; the GLF based on bending moment (MGLF) and the GLF based on shear force (QGLF) increase significantly with height, and the traditional GLF methods underestimate the maximum wind effects.