This paper presents results of an analytical and experimental investigation aimed at describing the turbulent momentum transfer mechanism in the separated-flow region of a rectangular cavity facing an oncoming turbulent boundary layer. A flow model of the mixing region in the slot postulated on the basis of eddy diffusion in free jets gives values of velocities and drag in good agreement with the measurements. The results further point to the significant effects exerted by the oncoming boundary layer on transfer rates from the slot. Flow-visualization pictures show some interesting vortex patterns inside the cavity when height-to-width ratio is varied between values of 1 and 3.

An experimental and analytical study is presented in this paper describing heat transfer in the region of separated flow over a two-dimensional rectangular cavity (of variable depth-width ratios) facing an oncoming turbulent boundary layer of variable thickness. The analysis, based on a prescription of eddy diffusion in the mixing region, predicts a heat transfer correlation, in terms of the foregoing variables, resulting in good agreement with the data. Experiments were performed with conditions of uniform temperature and uniform heat flux at the cavity walls and revealed no substantial difference between the two methods on the final correlation.

An analytical study is presented which describes the laminar accelerating flow of a thin film falling along a vertical wall. The approximate mathematical solution is given with emphasis on the growth and decrease of the boundary layer and film thickness, respectively. These resultant solutions are given in closed form and are found dependent upon two-dimensionless variables: φ2=3U0νgh02 and ζ2=1+2gh0x¯U02.

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