地铁屏蔽门条件下隧道湍流场的微波折射率结构常数建模

Modeling the microwave refractive index structure constant in subway tunnels with PSD system

地铁隧道内的湍流会造成空气折射率的随机变化,进而影响到隧道环境无线通信的质量。湍流的强弱可以用折射率结构常数来表征。文章基于流体力学基本原理,推导了地铁站区安装屏蔽门条件下的隧道活塞风速公式,并结合Tatarskii估算方法,建立了一种适用于不同地铁运营状况的隧道微波折射率结构常数模型。仿真分析可知:地铁运营高峰期的隧道折射率结构常数较小,隧道阻塞比和列车速度对隧道折射率结构常数影响较大,安装地铁屏蔽门能够在一定程度上降低隧道折射率结构常数。该模型为研究微波在地铁隧道湍流环境下的传播特性提供理论参考。

The turbulence in subway tunnels will cause the random fluctuation of atmospheric refractive index, and therefore re-duces the communication quality of wireless systems. The turbulent intensity can be described by atmospheric refractive index structure constant. We obtain the equation for calculating tunnel piston wind by following the fundamental principles of fluid mechanics. And basing on the Tatarskii estimation methods, the model for calculating microwave refractive index structure con-stant in subway tunnels is established, which is suitable for different subway operation conditions. The simulation results show： the refractive index structure constant is much lower during the rush hour of subway. The tunnel block ratio and train speed have obviously efifect on the refractive index structure constant, meanwhile the subway platform screen doors （ PSD） system can re-duce the turbulent intensity. This model provides reference for further researches on the microwave propagation in subway tun-nel turbulent environment.