Iteration-Based Recycling and Reshaping Method for Inflow Turbulence Generation and Its Evaluation

Abstract

For the analysis of the aerodynamic characteristics of the buildings immersed in the atmospheric boundary layer (ABL), it is necessary to generate a turbulence velocity field with similar temporal and special characteristics to the ABL to obtain a reliable result. In this paper, an improved precursor simulation method called the recycling and reshaping method (RRM) is proposed to generate a turbulent boundary layer in an LES model. The laminar inflow is firstly disturbed by the virtual roughness blocks realized by adding drag force term in the momentum equation, then the inflow velocity profile is reshaped every several steps to adjust the streamwise velocity profile in the downstream target area to meet the requirements. The final turbulence field generated by RRM with virtual roughness blocks is in good agreement with the target velocity conditions. Then, the simulation of the wind-induced pressure on an isolated low-rise building surface is carried out, using the generated turbulence boundary layer as inflow. The comparison between numerical results and TPU aerodynamic database shows that the time-averaged wind-induced surface pressure obtained by LES can be considered in good accordance with the measurements over the whole building surface. However, the non-ignorable deviations for the fluctuating pressure result in the flow separation corners still exist.

Keywords

• inflow turbulence generation
• source term
• large eddy simulation (LES)
• atmospheric boundary layer (ABL)
• low-rise building