傾斜壁面を有する建築物の周辺気流

抄録

This paper reports the wind tunnel experiments conducted to study the relation between the air flow and the shape of buildings, with the slopes of walls in focus. It aims at determining a proper gradient of wall which diminishes the strong wind region near the surface around buildings. A rectangular model of D40×W40×H80mm was used as the standard control. The test objects put in the tunnel were trapezoidal models with sloped walls, of the same D and H but 6 different W (i.e. angle of slope). Then the bottoms and tops were reversed and the models were exposed by two directions of wind likewise. All the 24 kinds of test were divided into 4 types of series according to the wind direction and standing of models, and named YS, YRS, XS and XRS types, as shown in Table-2. Measurements were performed in the three dimensional way for the air flow around each model, explicating the distribution of wind velocity totally not limiting to the near surface region. The result is as follows: The strong wind region near the surface diminished most significantly in YS series and then in XRS series, when the angle of slope is expressed in tanθ≧2/8〜3/8. The effects were in the opposite direction in XS and YRS series, by far worst in the latter. The tendency strengthened as the slope angle of walls increased against vertical plane.