坑道壁面から通気への熱伝達率予測計算式の提案

抄録

In this paper, the formulae estimating the average heat transfer coefficient (α_m) from the airway surface to the air stream in a mine gallery are proposed. They are the results of the experimental model studies which are reported in this paper and in previous ones. One of the main points is that the formula most suitable to the surface condition of the gallery has to be used.
On the base of the similarity law of heat transfer, the validity of the proposed formulae was checked with the “in situ” data already published. The estimated values of the formulae and the data were in good agreement.
Also, a generalized formula (Eq.(9)) applicable to the airways of various surface conditions was obtained. From this formula, α_m can be estimated, when the mean diameter (Dm), the Reynolds number (Re) and the friction factor (f) of the gallery are known. In case of the uniformly granular type rough surface, Eq.(9) may give smaller values in the range of 45 percent. On the other hand, in case of the timbered gallery with steel or wooden timberings etc., Eq.(9) may give larger values in the range of 45 percent.