Representation of complex objects in a new Cartesian coordinate urban street atmospheric numerical model

We intend to develop a new urban street atmospheric numerical model in Cartesian coordinate, which is expected to treat any complex object (buildings, etc.) explicitly in urban street with a finer resolution. In this work, the finite volume method (FVM) in conjunction with the SIMPLER (Semi-Implicit Method for Pressure-Linked Equation Revised) algorithms is used for calculations on a staggered grid. Abandoning the customary terrain-following normalization, we choose the Cartesian coordinate in which the height is used as the vertical one. Blocking-off method is introduced to handle all of complex objects. For the spatial and temporal discretizations, higher-order upwind convection scheme is employed, and fully time implicit scheme is utilized. As a preliminary test, the model has been run on flows over cube, complex building blocks in urban street. Result of simulations is present, which shows the potential of our proposed approaches for the new urban scale model development.