城市街道峡谷形状对燃气管道泄漏扩散影响CFD模拟

A CFD Simulation of the Gas Leakage Diffusion in the Urban Street Canyons with Different Structures

构造了2种不同形态的街道峡谷横断面CFD模型,所构建的模型由3栋不同高度的楼房并行组成,风向垂直于建筑物。并且用这些模型模拟了在3种不同风流速度条件下的街道峡谷流场和泄漏燃气的扩散情况。模拟结果表明,在建筑物的影响下,峡谷内的流场形成的旋涡造成独立而稳定的循环气流,从而影响建筑物迎风面与背风面泄漏燃气的扩散情况。建筑物附近风速的大小和分布也与泄漏燃气的扩散紧密相关。最后基于模拟结果提出了相应的应急措施。

Two street canyons cross section CFD models with different structures are constituted. The urban street canyons are simulated by three buildings with different heights parallel to each other and perpendicular to the wind. The simulations are carried out with three ambient wind velocities, and the models are applied to simulating the flow patterns and the leakage gas dispersion. The results show that the circulation air of the inner airflow fields in the street canyons has significant effects on the dispersion of the leakage gas on the leeward and windward walls. The dispersion and the concentration values of the gas are closely related with the nearby velocity magnitude. Based on the results of the simulations, some emergency measures are also presented.