中文摘要：

以厨房天然气泄漏为例，以三维K—ε湍流模型为基础，以计算流体动力学（CFD）为分析手段，以室内各特定空间点和空间面为研究对象，对天然气泄漏后的体积分数进行模拟和分析。由于天然气密度小于空气密度，天然气泄漏后在竖直方向的扩散速度大于在水平方向的扩散速度，易在房间上部积聚。天然气泄漏达到爆炸极限的体积分数分布区域是一个有一定厚度的水平区域。

英文摘要：

Taking natural gas leakage in kitchen for example, the volume fraction of leaked natural gas at indoor given spatial points and surface is simulated and analyzed by CFD software based on the three-dimensional k-ε turbulence model. Since the density of natural gas is less than that of air, the diffusion rate of leaked natural gas in vertical direction is greater than that in horizontal direction, and it is easy to accumulate at upper part of chamber. The distribution area of leaked natural gas with the volume fraction reaching the explosion limit is a level area with certain thickness.