摘要
本工作是在日本京都大学,防灾研究所的龙卷模拟实验室,用流体动力学模似实验方法研究三种不同粗糙表面对龙卷涡旋的影响。实验中,用热线风速表及微型风向标,测定了五个不同高度上的水平风速和风向分布,揭示出在不同粗糙表面上,龙卷涡旋的风速和风向分布特征。通过不断改变模拟装置的涡旋比S,发现当S值超过某一数值后(S>1.5),在不同粗糙表面上,龙卷涡旋的涡核尺寸将趋于一致。实验结果可进一步解释自然界中的观测事实,并对某些理论研究提供实验依据。
In this paper, by using the method of experimental simulation in laboratory, the effects of three various rough surfaces on tornado-like vortices are studied in the laboratory for simulating tornado vortex at the Disaster Prevention Research Institute, Kyoto University, Japan.In the experiments, the distribution of the horizontal wind speed and direction at five different heights were measured with a heatwire anemometer and micro-wind direction indicator. The characteristics of wind speed and direction distribution for the tornado vortex on the various rough surfaces were first revealed with the simulative method of laboratory. By changing the swirl ratios(S = tan θ/2a) of simulation device, it is found that the scales of tornado-like vortex core will almost become identical, when the swirl ratio S exceeds a certain value (S>1.5).The experimental results not only explain the observed fact in the atmosphere but also provide the experimental bases for some theoretical research.
出处
《气象学报》
CSCD
北大核心
1989年第1期34-42,共9页
Acta Meteorologica Sinica
