Reliable description of the inflow boundary conditions of the fully developed turbulence in atmospheric boundary layers for large-eddy simulation (LES) has been a subject of significant research interest due to its considerable impact on simulation results. In existing synthetic random Fourier methods for generating inhomogeneous inflow turbulence, the inhomogeneous field can be obtained by superimposing multiple homogeneous turbulence fields, each weighted by an assigned weighting function. However, inappropriate mapping strategies may distort the spatial correlations and continuity of turbulence structures from the targeted values, which could further deteriorate the simulation results. In this study, the impacts of the weighting functions on the total-energy profiles, spatial correlations, and the continuity condition of turbulence are clarified, based on which an adaptive energy-preserving mapping (AEPM) strategy is developed. The results from a priori numerical test demonstrate that inflow turbulence fields generated by the established synthetic random Fourier framework in combination with the AEPM accurately preserve the target turbulence energy profiles while maintaining good agreement with spatial correlation properties. Furthermore, the robustness and effectiveness of the AEPM are demonstrated through three LES case studies. Case 1 and Case 2 simulate atmospheric boundary layers around an isolated rectangular building and are validated against experimental data under neutral and unstable thermal stratification, respectively. In these two cases, wall-modeled LES (WMLES) results are compared with wall-resolved LES to investigate the performance of WMLES in urban environment simulations. In Case 3, the building in Case 1 is removed to form an empty domain, in which downstream turbulence statistics are evaluated to further assess the AEPM-generated inflow.

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• Boundary layers
• Structure & turbulence of boundary layers
• Turbulence