Rayleigh 수가 큰 경우（5×10⁷<Ra<1.5×10¹¹） 격막을 통하여 물질전달이 일어날 때 격막주위에서 발생되는 계면대류의 영향을 정량적으로 고찰하였다. 가시화를 통해 관찰된 유동양상과 전달량을 바탕으로 경계층을 단순확산층과 에디발생에 의해 교체되는 대류층으로 구분하는 전달기구모델을 제시하였다. 또한 대류층의 유동상태는 실험에서 측정된 에디발생주기를 Rayleigh 수의 관계로 표현하고, 이를 전달기구모델에 적용시키는 새로운 접근방법에 의해, Rayleigh 효과에 의한 자연대류시 Rayleigh 수, 유체층의 두께, 확산층 두께로 표시되는 Sherwood 수의 상관관계식을 얻었다. 본 실험범위에서 확산층의 두께는 거의 일정한 값을 나타냈으며 실험치는 아래식에 의한 결과와 잘 일치하였다.
Sh=0.29Ra^0.25-0.0671（δs/L） Ra^0.51-exp[3.86(L/δ_s)Ra^-0.25]² erfc[3.86(L/δ_s)Ra^-0.25]

The effects of interfacial convection were quantitatively investigated at high Rayleigh numbers （5×10⁷ < Ra < 1.5×10¹¹）, when a solute was transferred through membrane. A theoretical model for mass transfer was suggested on the basis of the flow patterns which had been observed by shadowgraph. It was assumed that turbulent mass transfer in the present system was controlled by two mechanisms:(1) steady state molecular diffusion in a thin layer and (2) unsteady convection of buoyant elements in its adjacent layer. The generation periods of buoyant eddies were correlated by the Rayleigh number. By relating these results with the model, a correlation for the Sherwood number was obtained as a function of the Rayleigh number, the thickness of a whole fluid layer and the thickness of a diffusion layer. The thickness of a diffusion layer was found to be almost constant. The present experimental results were well represented by the following correlation.
Sh=0.29Ra^0.25-0.0671（δ_s/L） Ra^0.51-exp[3.86(L/δ_s)Ra^-0.25]² erfc[3.86(L/δ_s)Ra^-0.25]