Wind environment (1)

[13] Evaluation of an extra term F_k in urban canopy model for RANS simulation based using LES data

Shu Watanabe¹, Hiroaki Ato², ○Tsubasa Okaze³, Akashi Mochida² (1.Kajima Corporation, 2.Tohoku University, 3.Tokyo Institute of Thechnology)

Keywords:Canopy model, LES, RANS, Turbulent kinetic energy, Production term

This study proposed an evaluation method for the extra term of canopy model, F_k, which is added in the transport equation of turbulent kinetic energy (TKE). In the proposed method, the extra term, F_k, is evaluated from the difference of horizontal average of production term for TKE calculated by using LES data at each computational mesh and estimated production term for TKE in canopy layer based on the horizontally averaged Reynolds stress and wind velocity by LES. LES analyses were performed under the conditions of several gross building coverage ratios to obtain the turbulence statistics within the urban canopy layer. Then, the extra terms, F_k, was directly calculated from the LES data. Finally, the relationships between the gross building coverage ratio and turbulent statistics, and the extra term, F_k, within the canopy layer were investigated.