Flow-Visualization by Means of Soap Bubbles on Snowdrift around the Huts at Syowa Station

Abstract

The wind tunnel tests were conducted in order to predict profiles of the snowdrift formed around the buildings with the pilotis built at Syowa Station in Antarctica on the following assumptions. That is, assuming that the snow flakes in the wind velocity fields exceeding the certain mean wind velocity flow along with the wind and the other snow flakes in those fields not exceeding it tend to accumulate on the ground surface, the profiles of the snowdrift around the buildings can be predicted under the blizzard. The results of the wind tunnel tests (the flow-visualization by means of soap bubbles and the measurement of wind velocity distributions) using two-dimensional models are as follows ; 1) The profile of the snowdrift changes according to the surface friction velocity of the surface boundary layer U_* and the altitude of the pilotis h. 2) The profile of the snowdrift can be predicted in the division of the wind velocity field at the altitude Z satisfying in U/U_≒0.5. 3) The variation of the snowdrift profile can also be expressed by the index K (eq. 9) of the fluid energy of the mean wind flowing the pilotis. Since the index K is a function of U and h, it is useful for the planning information of buildings.