论文标题
使用TensorFlow进行野外火灾预测的高分辨率大涡模拟框架
A High-resolution Large-eddy Simulation Framework for Wildland Fire Predictions using TensorFlow
论文作者
论文摘要
在过去的几十年中,随着野火的影响越来越严重,我们在广泛的条件下预测野生火灾行为的能力持续了压力。实现此目标的一种方法是通过耦合的火/气氛建模工具。尽管在提高身体保真度方面取得了重大进展,但现有的建模工具并未充分利用新兴的编程范式和计算体系结构来实现高分辨率的野火模拟。通过解决这一差距,这项工作提出了一个新的野火模拟框架,该框架可以以负担得起的计算成本对燃烧的物理表示,使景观规模的野火模拟。这是通过在Tensorflow编程范式中开发耦合的火/气氛模型来实现的,该模型可以在张量处理单元(TPU)硬件体系结构上实现高效且可扩展的计算。为了验证该仿真框架并证明其效率,进行了开处方的火灾实验II(Clements等,2019)的模拟。通过考虑针对网格分辨率的参数研究,我们表明,诸如体积热量释放和燃烧速率之类的全局数量对0.5 m和2 m之间的水平网格分辨率不敏感,这足以预测与大气中的大气式湍流结构相关的火灾间歇性和动态火灾。
As the impact of wildfires has become increasingly more severe over the last decades, there is continued pressure for improvements in our ability to predict wildland fire behavior over a wide range of conditions. One approach towards this goal is through coupled fire/atmosphere modeling tools. While significant progress has been made on advancing their physical fidelity, existing modeling tools have not taken full advantage of emerging programming paradigms and computing architectures to enable high-resolution wildfire simulations. By addressing this gap, this work presents a new wildfire simulation framework that enables landscape-scale wildfire simulations with physical representation of the combustion at affordable computational cost. This is achieved by developing a coupled fire/atmosphere model in the TensorFlow programming paradigm, which enables highly efficient and scalable computations on Tensor Processing Unit (TPU) hardware architecture. To validate this simulation framework and demonstrate its efficiency, simulations of the prescribed fire experiment FireFlux II (Clements et al., 2019) are performed. By considering a parametric study on the mesh resolution, we show that the global quantities such as volumetric heat release and fire-spread rate are insensitive to the horizontal mesh resolution within a range between 0.5 m and 2 m, which is sufficient for predicting fire intermittency and dynamic fire properties associated with fine-scale turbulent structures in the atmospheric boundary layer.