無風時における帯状熱源からの上昇熱気流の温度流速分布 : 市街地大火における火災気流に関する基礎的研究

抄録

In order to clarify the preventive method of big fire in a built-up area of wooden houses, it is important to discuss the estimative method of temperature fields on the fire gas flow and the general behavior of the flame on big fire. This paper purposes to obtain a method of estimating the temperature distribution of fire gas on big fire. The author has considered fire spread and burning behavior on big fire, attempted to assume a belt-shaped heat source as the experimental model of burning area. The similarity theory in the case of the thermal convection from a belt-shaped heat source is derived by determining a few parameters appearing in this model. The experimental studies in the thermal convection from a line heat source was already performed by S. Yokoi. The author has first begun to try the approximate solution in the case of a line heat source, and attempted to compare the results with Yokoi's case (transverse excess temperature and velocity distributions). The results of calculation fitted better to the Yokoi's equation. A mathematical model on the turbulent diffusion flames from a belt-shaped heat source was derived by a few parameters based on similarity analysis considered in the case of the approximate solution. In order to examine the theory considered in this paper, measurements of temperature and velocity were performed in a tunnel placed a belt-shaped vessel for burning alcohol. The measured temperature and velocity distribution was satisfied with the validity of the theory considered in this paper.