New experimental results on vapor deposition were presented in the presence of nonequilibrium condensation on a vertical flat plate.
In this experiment, the local deposition rates of $Na_2SO_4$ on the sufficiently cooled target surfaces were measured using flashing evaporation technique and the intensities of laser light scattering which were occured by condensate in laminar boundary layer were measured locally.
The deposion rates per unit concentration of $Na_2SO_4$ were decreased with the increase of free stream concentration and the distance from the edge, but not changed with varying wall temperature of which range was controllable range in this experiment. The decrements of deposition rates along the surface are dominant when free stream concentration was high.
This results shows that nonequilibriun, condensation was occured in boundary layer and the degree of nonequilibrium can be examined with the ratio of relaxation time( this is concerned with concentration ) and residence time( this is concerned with velosity and distance ).
Also this study shows that the ratio is closely related the degree of nonequilibrium in view of molecular dynamics.
