Numerical simulations of flow-field interactions between moving and stationary objects in idealized street canyon settings

Numerical simulations of an ideal model of street canyons with moving objects in the horizontal plane were conducted. The simulations were based on the unsteady two-dimensional incompressible Navier–Stokes equations, discretized on an overlapping grid with a numerical scheme that is second-order accurate in both space and time. The computational domain consists of a rectangular background with eight fixed objects arranged in two parallel columns representing the street canyon. Four identical objects were put in each column equidistantly. One or two identical objects were moving along the symmetry line of the computational domain. The objects were either circular or rectangular with rounded corners in shape. The numerical method was first validated by comparing with existing experimental and simulation data. A parametric study was carried out to investigate the influence of the characteristic parameters (such as canyon width, velocity of the moving objects, and separation distance between them) on the wake of the moving objects.