陽炎現象の研究

(1) 陽炎の中の乱流輸送現象

抄録

Recent developments by Monin-Obukhov (1954) and Priestley (1957) in the study of natural convective phenomena near a heated surface have been made use of to obtain the turbulent transport flux equation applicable to phenomena under the extremely weak wind conditions in the hot daytime, in which the ordinary aerodynamic method of estimating the turbulent transport flux can not be applied. The “-1/3 power law” for the vertical temperature distribution and the “-4/3 power law” for the vertical temperature gradient distribution have been examined with the observations made by us and by Ramdas (1953). These laws give an expression of the turbulent transfer coefficient K as follows:
K=H_C*(g/Θ₀)^1/2|dΘ/dZ|^1/2Z²,
where H_C* is the Priestley's (1957) constant of the value of about unity. The value of K can be calculated by observing the air temperature distribution and the transport flux is thus calculated as the product of K and the gradient of physical quantities concerned. Making use of the data given by Ramdas (1953) some estimations of K and q, the heat flux, have been carried out.