Local Mass Transfer Coefficients at Walls Impinged by Unsubmerged Multijets Issued from Very Porous Distributors

The paper deals with the experimental determination of the spatial distribution of local mass transfer coefficients at a solid surface receiving unsubmerged liquid multijets issued from several categories of distributors. The experimental technique uses microelectrodes imbedded in the solid surface and allows the local mass transfer coefficients and the local shear stress to be determined at the same places. Very porous distributors lead to distributions much more uniform than those obtained with poorly porous distributors. A special interest is given to distributors made of metallic foam. The experimental mass transfer coefficients measured at the stagnation point are compared with correlations from the literature.