室外微气候既决定室外环境的舒适性和空气品质，又影响建筑能耗及自然通风效果，因此室外微气候的研究及优化设计在人居环境被日益重视的今天具有很重要的意义。当前我国正在大量新建住宅小区，迫切需要能配合建筑设计对其室外环境进行优化的模拟分析方法。 目前室外模拟广泛应用的湍流模型是标准k-ε模型及其各种改进模型，这类模型模拟分析较为准确，但其计算量较大往往无法与建筑设计进程相配合。相比较标准k-ε两方程模型而言，零方程模型能显著减少计算量，但目前缺乏专门针对室外建筑绕流模拟开发的零方程模型。本文对现有的用于空气流动模拟的零方程模型进行分析总结，并对其中两种主要的零方程模型在建筑绕流模拟领域进行应用，证实模拟结果都不理想。 通过对大气边界层建筑绕流中标准k-ε模型计算结果中湍流粘性系数的分布和建筑存在对流场混合长度产生影响的分析，笔者提出两种新的两层零方程模型。内层为混合长度模型形式，外层为MIT零方程模型形式。文中给出了新的零方程和标准k-ε模型的大量数值模拟结果对比，并与风洞实验结果进行比较以验证新的零方程模型的室外绕流模拟的适用情况。第一种零方程模型对于建筑高度和长高比统一的工况，如一片建筑形态相似的住宅小区，在计算时能够节约计算时间并得出与标准k-ε模型很接近的模拟结果。第二种零方程模型对于建筑形式复杂的工况，能够方便快速的得出较为理想的模拟结果。文中最后把第二种新的零方程模型应用于实际小区算例中，模拟结果与实测数据较为吻合。 本文提出的两种新的适用于室外建筑绕流模拟的零方程模型，使提高模拟室外绕流的计算速度成为可能，有望在实际工程中推广应用。

The research on the outdoor micro-climate is very important for two reasons. First, the outdoor micro-climate determines the comfort and air quality of the outdoor environment. Second it has great influence on energy consumption and natural ventilation in building. Since the residential area in China is increasing quickly, a quick way to simulate the outdoor environment of the residential area becomes essential. Currently, k-ε model and relevant improved models, which require significant amount of computation time, are the most widely used turbulence model in outdoor simulation.From the perspective of engineering application, this paper studies the interaction between the buildings and the coming air flow through literature review and by analyzing the results of air flow simulation around the buildings using k-ε model. It is found that the result of the traditional mix-length model and the MIT zero-equation model in the simulation of the flow around the buildings are not satisfactory. There are two reasons. First, the definition of traditional mix-length is not suitable for the flow around the building. Second, the MIT zero-equation model would underestimate the turbulent viscosity coefficient in the shadow area behind the building.Through qualitative analysis on the distribution of the turbulence viscosity coefficient in the simulation of flow around the building in the atmospheric boundary using k-ε model, and the impact on the mix-length by the buildings, the author proposes two new two-layer zero-equation models: mix-length model for the inner form and MIT zero-equation model for the outer form. In this paper, a large number of simulation results of the new zero-equation model and the comparisons with k-ε model are provided to illustrate the application of the new zero-equation model in the outdoor rounding flow simulation. The first new zero-equation model is suitable when the heights and the rates of length/height of the buildings are similar, such as one similar residential, and it will save commuting consumption and get results close to the traditional k-ε model. The second new zero-equation model is suitable for more complex conditions, and it can get satisfactory results conveniently and quickly. In the last section of this paper, the second zero-equation model is applied to a residential case study. The results are compared with the measured value and proved to be consistent. The simulated wind directions are fully consistent with the k-ε model results, and same with most of the measured sample points.The calculated speed of outdoor rounding flow simulation is hence possible to speed up. New zero-equation models in this paper are expected to be widely applied in engineering projects.