摘要
本文研究了竖井型公路隧道自然通风模式下的气流运动与污染物扩散的问题。取相邻两竖井间隧道主体为一个控制体。在一维不可压缩的前提下,根据质量守恒与能量守恒原理建立并求解了各控制体的气流运动方程。在考虑隧道紊流是由大气湍流与汽车运动共同造成的前提下,建立了各控制体断面的污染物扩散方程组,采用"局部单向化假设"确定出口边界。算例结果表明:各控制体断面风速及各竖井进(排)风状态呈现出周期性的变化规律。车速较高时,竖井的存在有助于降低隧道内及出口处CO浓度;而低车速情况下,竖井布置不当反而会抑制隧道内污染物的扩散。
Problems of air flow and contamination＇s dispersion were studied under the model of natural ventilation for tunnel with shafts. A main body tunnel between any two adjacent shafts was taken as a control volume. Premising one-dimensional and incompressible, each control volume＇s air flow motion equations were established and solved, which were based on methods of mass and energy conservation. Contamination＇s dispersion equations of each control volume were established, premising that turbulence inside the tunnels was caused by atmospheric turbulence and vehicle＇s movement. Local-unidirectional assuming was used as the outlet boundary. A calculated example showed： a law of cyclic variation appeared in the air velocity of each control volume＇s cross-section, also in the draught of each shaft. When vehicle＇s velocity was faster, Shafts would help to decrease CO concentration of tunnel＇s interior and its outlet. While vehicle＇s velocity was lower, irrational layouts of shafts would suppress the contamination＇s dispersion in tunnel.
出处
《建筑热能通风空调》
2009年第4期18-22,共5页
Building Energy & Environment
关键词
隧道工程
污染物浓度
局部单向化假设
扩散方程
自然通风
tunnel engineering, concentration of contamination, local-unidirectional assuming, dispersion equation,natural ventilation
