摘要
为城市绿化建设,以k-ε两方程湍流模型为基础,模拟计算小规模树林区对气流穿越,研究树木对城市微气候影响。以计算流体力学(CFD)软件Phoen ics为计算平台,在标准k-ε模型中k方程和ε方程中添加源项,建立一套三维树冠流计算模型。以G reen的风洞实验实测值为依据,对于四棱锥、四棱台和长方体3种逐步简化的树冠模型,比较其计算过程与计算结果之间的差异。其中采用长方体树冠模型就能够得到比较准确的模拟计算结果,具有建模简便、计算快捷、收敛性好的优点。
Making the city green is an important part of urban construction and trees have a significant effect on the urban micro-climate. A 3-D k-ε turbulence model was developed to model air flow both through and above a small forest stand in an otherwise undisturbed boundary layer flow. The effects of the forest canopy were modeled using a momentum sink and a source term to generate turbulent energy. Sink terms were also added to the k and equations to account for the additional turbulence energy losses. The flow equations were solved using the Phoenics fluid dynamics program. Predictions from the model agreed well with wind tunnel data. Three different forest canopy shapes were used, a pyramid model, a frustum of a pyramid model, and a cuboid model. The results were compared with the wind tunnel data as a reference. The results show that the different canopy shapes affect the results with the cuboid canopy model giving the best fit with the experiment data well, with less computational time.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第6期753-756,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(59836250)
关键词
城市微气候
树冠模型
k-ε两方程模型
源项
计算流体力学(CFD)
urban micro-climate
plant canopy model
k-ε two-equation model
source/sink terms
computational fluid dynamics （CFD）
