Analysis and modeling on thermal and aero-dynamical forcing effect brought by urban canopy.

开发了一套完整的建筑块体阻力和城市冠层标量通量输送的直接测量系统，进行了系统、全面的风洞实验，识别了不同城市几何背景下的体积阻力(动量)输送系数和体积阻力标量输送系数。我们确定了一个良好的第一步，只要我们选择适当的参数，就能以某种方式获得两个总体传输系数与城市几何的普遍关系。研究表明，建筑物的密度、各建筑物的细长以及高度的变化、排列的随机性都是影响城市树冠所带来的湍流结构传递系数的重要因素。我们还采用了风实验以外的其他方法；PIV技术和CFD，确保从湍流结构的角度调查城市树冠内和略高于城市树冠的真实情况。LES是最常用的CFD技术之一，它揭示了冠层上方出现的湍流组织结构(TOS)与冠层内的动力学有关，对热力和空气动力强迫效应有显著影响。

The complete set of elaborated direct measurement systems for both drag force acting on a building blocks area and scalar flux transfer from urban canopies, which we developed in the previous project, systematic and comprehensive wind tunnel experiments to identify the so-called Bulk Drag (Momentum) Transferring Coefficient & Bulk Drag Scalar Transferring Coefficient for various urban geometric contexts were carried out. We identified a good first-step inception to get somehow universal relations of both two bulk transferring coefficients with urban geometry as long as we choose appropriate parameters. We grasped that not only building density but also slenderness of each building blocks as well as height variation, array randomness are crucially affecting on the transferring coefficients through turbulent structure brought by urban canopies. We also took other methodologies than the wind experiment; PIV technique and CFD that make sure to investigate what is really happening in and just-above urban canopies in terms of turbulent structure. LES, one of up-most CFD techniques, reveals that TOS (turbulent organized structure) emerged above canopies in connection with dynamics within canopies significantly affects onthe thermal and aero-dynamical forcing effect.