球形屋顶积雪分布风洞试验研究

Wind Tunnel Test of Snow Distribution on Spherical Roofs

降雪天气下,屋面的积雪随着屋面形式和风场的变化而变化.正确地估计建筑物屋面的积雪分布,对于保证结构的安全使用十分重要.现有屋面积雪分布风洞试验研究,仅对非曲面屋面进行了研究,且只模拟了积雪的重分布.为了预测降雪天气下屋面上积雪的分布形式,采用喷射硅砂颗粒的方式进行了降雪模拟风洞试验.通过对比高低屋面试验结果和实测结果,发现低屋面上的积雪规律基本一致,验证了降雪模拟试验的可行性.采用不同矢跨比的球形屋面模型进行风洞试验,获得了不同风速、不同矢跨比条件下球形屋面上的积雪分布规律.通过不同时长的风洞试验,发现屋面积雪呈潮汐式增长的现象,试验时长明显影响积雪厚度,但对于球形屋面积雪范围的影响不大.

The snow on the roof changes with the shape of the roof and the wind during snowfall.It is crucial to estimate accurately the snow distribution on the roof to ensure the safety of structure.The conventional wind tunnel test method is limited to the study of snow redistribution on flat roof,and only the snow redistribution process was simulated.The snowfall simulation wind tunnel test was carried out by spraying silica sand particles on the roof to predict the distribution of snow on roofs during snowfall.By comparing the test results on the stepped roof and the measured results,it is determined that the snow cover on the low roof is basically the same,which verifies the feasibility of the snowfall simulation test.Snowfall simulation tests were carried out using spherical roof models with different risespan ratios,and the distribution of snow accumulation on spherical roofs with different wind speeds was obtained.Using the wind tunnel tests with different durations,it is determined that the snow on the roof increases in a tidal manner.The duration of the test evidently affects the thickness of the snow,but has little effect on the snow coverage on the spherical roof.