Evaluation on wind characteristics around a steep simple terrain in a uniform flow-case of a two-dimensional ridge model

The purpose of this research is to construct a database of a non-stratified airflow past a steep simple terrain under an imposition of a uniform flow, and, in addition, is to do the accuracy inspection of the numerical model under development at present. This numerical model is referred to as the RIAM-COMPACT (Research Institute for Applied Mechanics, Kyushu University, Computational Prediction of Airflow over Complex Terrain), and is for the purpose of the prediction of airflow over complex terrain with several m to several km. This paper describes the experimental and numerical study of a non-stratified airflow past a two-dimensional ridge in a uniform flow as the first phase. The Reynolds number, based on the uniform flow and the height of the ridge, is about 10 ⁴. Airflows around the ridge include the unsteady vortex shedding. Attention is focused on airflow characteristics in a wake region. For this purpose, the velocity components in the streamwise direction were measured with a SFP (Split-Film Probe) in the wind tunnel experiment. In addition, the flow visualization was performed by using the smoke-wire technique. Through comparison of the experimental and numerical results, they showed a good agreement. The accuracy of both of the wind tunnel experiment by the SFP and also numerical simulation by the RIAM-COMPACT were confirmed as the result.