Inclusion of building-resolving capabilities into the FastEddy® GPU-LES model using an immersed body force method

Herein, we extend the immersed body force method (IBFM) from Chan and Leach (2007, ) to (i) be scale independent and (ii) control building surface temperatures. Through a specific drag-like term in the momentum equations, the IBFM is able to enforce essentially zero velocities within the buildings, in turn resulting in a no-slip boundary condition at the building walls.

In addition, we propose similar forcing terms in the energy and mass conservation equations that allow an accurate prescription of the building temperature. The extended IBFM is computationally efficient and has the potential to be coupled to building energy models. The IBFM exhibits excellent agreement with laboratory experiments of an array of staggered cubes at a grid spacing of Delta=1 mm, demonstrating the applicability of the method beyond the atmospheric scale.