地铁隧道壁龛式射流通风数值模拟

Numerical Simulation about Jet Ventilation in Niche Tunnel of the Metro

对地铁隧道壁龛式射流通风的特点进行了分析，建立了重庆某地铁区间隧道的单元通风段模型，设置压力、速度两种不同的进口边界条件，采用PHOENICS软件对隧道内部的速度场、压力场进行了模拟分析，发现隧道内断面气流速度分布存在一个波峰，峰值位于渐缩段末端断面，隧道内气流压力在风机吸入端达到最低值，在射流发展段呈现出渐变的非均匀的逆压运动，在射流发展段末端压力达到最大值，此后由于壁面摩阻损失的影响，在压力通风段压力逐渐降低；分析比较两种进口条件下隧道内部气流运动的不同点，主要体现在回流强度、射流发展段长度以及诱导通风量。

Analyse the characteristics about jet ventilation in niche tunnel of the metro. Establish single ventilation unit model of Chongqing metro tunnel. Set two different import boundary conditions, using PHOENICS software, simulate and analyse the velocity and pressure field in the tunnel. A peak flow located in the tapered end section is found by observing section velocity distribution inside the tunnel. At the fan suction side, the pressure reaches the minimum value. In the section of jet development, it shows the inverse gradient of the non-uniform pressure distribution, at the end of section of jet development, it reaches maximum pressure. Then as the impact of the wall friction loss, the pressure reduces gradually in the pressure ventilation section. The differences of jet flow in the tunnel under two import conditions are compared, the differences mainly reflect in the strength of return, length of the section of jet development and ventilation volume by inducing.