剥離流の影響を受ける屋上面気流場における流速変動の空間スケールに関する風洞実験: 建物近傍で生じる剥離流の予測手法に関する基礎的研究（その1）

摘要

建物屋上面に形成される剥離流内の流動現象を非定常流体解析により評価する際に計算格子解像度を決定する上で考慮すべき、空間スケールを明らかにすることを目的として、異なる空間フィルタをPIV測定結果に適用し、パワースぺクトル·平均流速·流速変動のRMS·乱流強度·分岐点·二次元Csに与える影響を検討した。検討の結果、以下の知見を得た。%In predicting the complex flow field caused by the separation flow around a building, previous studies have shown that Large Eddy Simulation(LES) can be superior to Reynolds-Averaged Navier-Stokes Equations(RANS). However, LES which is applied the coarse computational grid resolution can give inadequate results from the viewpoint of the accuracy and information quantity. Therefore, understanding the scale of velocity fluctuation can be important before determining the grid resolution. This paper focuses on the influence on the various fluctuation scale which generated by the separation flow. In this paper, the filtered velocity is obtained by applying spatial filters to the data of Particle Image Velocimetry (PIV). The results indicate that data of filtered velocity do not appear to change significantly when relatively large filters are applied.