泄漏原油在山体表面扩散规律数值模拟

Numerical simulation study on the diffusion law of leaked crude oil on the surface of mountain

以中缅原油管道沿线某典型高后果区为研究对象,通过提取管道所处实际山体地形特征,建立了大尺度山体真实地形三维模型。采用VOF方法模拟了当埋地管道破裂时泄漏油污染物在山体表面的动态运移扩散过程,分析了泄漏速度和地表植被对泄漏污染物扩散速率和扩散面积的影响规律。结果表明:原油泄漏扩散面积与泄漏初速度和地面粗糙度成反比,但当地表植被粗糙度高度超过原油平均冲击高度时,扩散面积对粗糙度高度不敏感。研究结果可为复杂山区油品管道发生严重泄漏事故后的救灾抢险工作提供理论指导。

In this paper,a numerical simulation study was carried out on the pipeline rupture and leakage caused by geological disasters in a high-consequence area along the China-Myanmar crude oil pipeline.After obtaining source elevation geographic data by locating geographic coordinates of the high-consequence area,we used the mapping software Global Mapper to generate contour lines and further generated 3D terrain surface through 3D modeling software Sketchup.Finally,a large-scale real terrain three-dimensional model of the mountainous area was established in ICEM CFD.The unstructured grids were deployed to the entire computational domain due to the great variability of surface curvature.Based on VOF multiphase model,we performed a computational fluid dynamics simulation of the leakage process of pipeline leakage oil pollutants on the surface of the mountain.The simulation results dynamically showed the leakage path and diffusion range of crude oil on the mountain surface.Besides,by analyzing the effect of the initial leakage rate and surface vegetation on the diffusion of leakage,the dynamic characteristics of the diffusion of the spilled oil pollutants on the mountain surface and the diffusion area change law were obtained.The results indicate that the initial leakage rate and surface vegetation are important factors affecting crude oil leakage in mountainous environments.The leakage rate mainly affects the time for the crude oil to leak to the designated location.The smaller the leakage rate is,the longer it takes for the crude oil to leak to the designated location.Moreover,the diffusion area of the leaked pollutants is reduced compared to the smooth mountain surface due to the restriction of flow resistance on the mountain surface covered by vegetation,but for the surface with evenly distributed vegetation,the diffusion area is not sensitive to the height of the rough unit.The results are significant and important to guide the disaster relief work after oil leakage in the complex mountain environment from a theoretical perspective and minimize the pollution and losses caused by oil leakage.