Evaluation of the coupling between NWP and LES-based CFD models for simulating urban boundary layer flows

Nakayama, Hiromasa   ; Takemi, Tetsuya*; Nagai, Haruyasu  

In order to simulate wind flows within and over urban areas under real meteorological conditions, coupling technique between NWP and LES-based CFD models is considered to be promising. Therefore, in coupling between both models, we applied a recycling technique to a strong wind event in Tokyo owing to the landfall of a major typhoon and compared with the observed data of time series of wind speed at a certain height. Although the observed ranges of wind fluctuations and gust factors were well reproduced in the LES, the effectiveness of this coupling approach has not been fully evaluated. In this study, we apply to the field experiments, the Joint Urban 2003 held at the central district of Oklahoma City on July 2003, and examine the coupling approach in comparison to the observed data in detail.