Because of the high population density and topographical characteristics of the many mountainous regions in the Republic of Korea, the buildings are constructed not only on flat land, but also on relatively flat terrain between slopes and mountains. The wind speed may increase between these mountains owing to the convergence effect, which is called the funnel effect. Because the funnel effect between mountains is difficult to assess quantitatively, it is evaluated by reproducing the mountain range in wind tunnel tests. In this study, the wind speed amplification factor was calculated according to the gradient (0.3, 0.4 ,0.5, 0.6) of the mountain and the distance(1 to 5 times the height of the mountain) between the mountains based on the idealized 2-dimensional mountain, and an empirical formula was derived. The higher the gradient of the mountain and the smaller the distance, the greater wind speed amplification factor, and the maximum was about1.12. An empirical formula to which this trend was applied was derived. Additional wind tunnel tests were conducted to verify the empirical formula, and the test data and the data calculated by the empirical formula were compared. As a result, the error rate of the empirical formula was about 2%. If the empirical formula is used in a case similar to the topography conducted in this study, it is expected that the funnel effect can be predicted more quantitatively.
한국은 높은 인구밀도와 산지가 많은 지형적 특성으로 인해 평탄지 뿐만 아니라 경사지와 산과 산 사이에도 건물을 건설한다. 산지 사이에서는 골바람효과로 인하여 풍속이 증가할 수 있다. 산지 사이의 골바람효과는 정량적으로 평가하기 어렵기 때문에 풍동실험을 통하여 평가한다. 본 논문에서는 2차원 산지를 대상으로 산의 경사도와 산지의 이격거리에 따라 풍속할증계수를 산출하였다. 산의 경사도가 높고 산간 이격거리가 좁을수록 풍속할증계수가 커지며 최대값은 1.12였다. 이러한 경향이 적용된 실험식을 도출하였다. 실험식의 검증을 위해 추가적으로 풍동실험을 하였으며 실험데이터와 실험식으로 계산된 데이터를 비교하였다. 그 결과, 실험식의 오차율이 약 2%였다. 본 연구에서 진행한 지형과 유사한 경우 추세식을 이용한다면 보다 정량적으로 골바람효과를 예측할 수 있다.