水喷淋控制烟气输运的大涡模拟研究

摘要

本文采用大涡模拟方法研究了烟气输运和水喷淋之间的相互作用问题.研究目的是探讨水喷淋(或细水雾)对烟气输运的控制和抑制的有效性和可行性.为了有效地模拟烟气输运过程,本文采用了低马赫数近似下的三维可压缩滤波形式的Navier-Stokes方程进行有限差分法数值求解.烟气的生成和运动采用携带燃烧反应热的Lagrangian粒子(热元模型)来模拟,同时喷淋器喷出的细水雾也采用模型模拟.在本文的研究中,烟气由一个独立的火池产生并且被一股来流(或风)驱动,从而在一个方形槽道里形成烟气输运,在火池下游槽道的顶部布置若干个喷淋器并喷出水雾,以便探讨水雾对烟气输运的控制作用.本文着重分析讨论了不同喷淋角和水雾半径下水雾对烟气输运的控制和抑制效果.%The interaction between smoke movement andwater spray is investigated by large eddy simulation(LES) approach. The object of this study is to deal withthe efficiency of the water spray (or water mist) on thecontrol and prevention of the smoke movement. The fil-tered three-dimensional compressible Navier-Stokes equa-tions under low-Mach-number approximation and the fil-tered species equations are solved by finite-differencemethod. The motion of the smoke is driven by Lagrangianparticles (thermal elements) carried the beat release ofcombustion, and the water spray is simulated by ejectingfrom sprinklers. In the present study, the smoke motiongenerated from an isolated pool fire and driven by an in-coming flow (or wind) in a rectangular channel is simu-lated. In the downstream of the isolated pool fire, watersprinklers array is set on the top wall of the channel to e-ject water spray. The effect of the water sprays with dif-ferent water spray angles and spray droplet sizes on thecontrol and suppression of the smoke movement is ana-lyzed and discussed.