Behavior of hot airflow heated by a fire in a tunnel with ventilation duct.

今年进行的实验结果如下：1.隧道火灾过程中模型风道内气流温度和运动的测量。通过增加模型风道中测量点的数量，进行了一系列隧道火灾实验，以测量精确的气流温度。常温和高温区域的气流通过烟管进行可视化。当风管倾角较小时，风道两侧有空气流入和流出，即风管上部有热气流出，下部有冷气流入。当倾角较大时，只在管道的下侧观察到空气的流入。在火灾的下风处，空气温度有不连续的现象，可视化也观察到了高度扰动的气流。斜井火灾实验是在九州煤矿研究中心国家资源环境研究所的斜井中进行的。在上风向和下风向条件下，观察了火灾加热的热气流行为。当初始风速大于1.7m/S时，即使在火灾过程中，气流仍继续向下流动。这一结果出乎意料，但如果再进行不同倾角的隧道火灾实验，将是非常有用的。用于模拟隧道火灾的计算机程序的开发该程序能够模拟气体扩散和排气通风系统。但是，它需要解决计算时间长、内存需求大的问题。

The results of experiments executed in this year are as follows.1. Measurement of airflow temperature and movement during a tunnel fire in a model duct.A series of tunnel fire experiments are executed to measure precise airflow temperatures by increased number of measuring points in a model duct. Airflow in a normal and hot temperature zone was visualized by a smoke tube. There were air inflow to and outflow from the duct at the both sides of the duct when the inclination of the duct was small, that is, heated air came out at the upper part of the duct and cold air flew in at the lower part of the duct. There observed only inflow of air at the lower side of the duct when the inclination was large. There ware discontinuity in the air temperature at the downwind of the fire and highly disturbed air flow was also observed by the visualization.2. Actual size fire experiments in an inclined shaft.Actual size fire experiments were executed in an inclined shaft at the National Institute of Resources and Environment, Kyushu Coal Mining Research Center. Behavior of hot airflow heated by a fire was observed during upwind and downwind conditions. The airflow continued to flow downward even during the fire when initial air velocity was more than 1.7m/s. This result was not expected one, however, it will be very useful if another tunnel fire experiments will be done using different inclination.3. Development of a computer program to simulate a fire in a tunnelThe program was developed to be able to simulate gas diffusion and exhaust ventilation system. However, it requires to resolve the long computation time and large memory requirement.