Numerical Simulation On Pedestrian Wind Environment And Improved Measures Of Large-Span Structures

The large-span structure is very sensitive to wind load and its surrounding wind environment is also rather complex due to its features of light quality, high flexibility, small damping and low natural vibration frequency. Bad pedestrian wind environment can make pedestrians uncomfortable, and cause partial damage to buildings. Meanwhile, people are increasingly concerned about the beauty of the structure modeling. Therefore, the aerodynamic measures such as wind guide plate and wind shield are used widely in large-span structures for the advantage of without changing the original structural system and architectural appearance.Currently, the main research methods of pedestrian wind environment are field measurement, wind tunnel test and numerical simulation. Among them, numerical simulation is time-saving, labor-saving, and highly flexible and it is not affected by the geographic conditions, climate, and model scale. These advantages make numerical simulation become an important method in the research on pedestrian wind environment and its improvement measures at present.Taking Yantai Railway Station as the engineering background, the research contents of the thesis consist of several aspects as follows:(1) A review of the development history and current study situation of pedestrian wind environment and an overview of that CFD plays an important role as wind tunnel test on research of pedestrian wind environment.(2) The thesis introduces the three main governing equations of CFD, and through the discussion of discrete form and method of equations, turbulence model and its application, the thesis introduces the current main theories and methods of numerical simulation of wind environment.(3)With CFD software, large-span structure were numerically simulated. Then it could calculate and get the results of pedestrian wind environment under the large roof in the different wind directions. As a result, the pedestrian wind environment of this building was evaluated based on the results of calculation.(4)Wind tunnel tests of the large-span structure model were carried out and the wind velocities of pedestrian level were measured under different wind directions. Comparing the results of wind tunnel tests with the CFD results, it verified the correctness of wind field distribution rule obtained from numerical simulations.(5)Three different kinds of aerodynamic measures are selected to improve the pedestrian wind environment under large-roof structures. Calculating and processing the final data of these kinds of measures and comparing the data obtained from wind tunnel tests, the overall improvement effect of these measures were evaluated.The results of this thesis can provide reference for wind environment evaluation and improvement for similar structures.