基于数值模拟的室内通风环境不同高度风场研究-控制工程专业论文.docx

ABSTRACT Due to the fact that industrial hazards frequently occur in urban areas, the more sophisticated investigation is needed to realize the rapid and precise detection of poisonous gas leak source, which is benefit to the development of economy and society. Considering that the toxic environment is not fit for human or animals to detect on-site, a few researchers attempted to locate the odor source using a mobile robot in the early 1990s, which is called robot-based gas leak source detection. In recent decades, although researchers have spared no effort to solve the problem, coming up with a series of tracking strategies however, there is not satisfying breakthrough. Reason is that there are still some key problems remaining unsolved: To begin with, there is no high simulation plume model. The numerical simulation environment for testing the gas leak source localization algorithms outperforms the real plume environment for the reasons that it costs less and we can easily control the parameters of the flow. In addition, the same simulation environment can be used many times to compare the performance of different searching algorithms. However, there is no universally accepted simulation plume which can perfectly match the real plume. Therefore the credibility of test results in the simulation environment needs to be improved. Moreover, in existing plume tracking algorithms most parameters, such as time-step, angle with the wind direction, are fixed, owing to the fact that we know little about the change pattern of the airflow which can affect the diffusion of the gas molecular. Apparently, such a fixed setting can’t adapt to the variation of environment. In response to those issues, this thesis presents a study of the following two aspects: Firstly, in order to learn more about the regular pattern of the three-dimensional flow field, a tool of computation fluid dynamics (CFD) software, FLUENT, is applied to numerically simulate airflow in the ventilated room. Bas