Sublimation Mass Transfer Through Compressible Boundary Layers on a Flat Plate

Abstract

Data are reported on rates of sublimation mass transfer from an adiabatic, sharp-edged flat plate exposed to air streams at Mach numbers of 0.43, 2.0, and 3.5. Thickness decrease of the subliming naphthalene coating, plate surface temperature, and flow conditions were measured. An analysis of friction and heat transfer in turbulent compressible flow has been extended to mass transfer at low rates. Agreement between theory and data is good over the entire range of Reynolds numbers from 3 × 104 to 9 × 106. The effect of compressibility on mass transfer is found to be slightly greater than on friction. The measurement of the sublimation rate of thin coatings of solids provides a powerful technique of obtaining local friction coefficients, being simpler and of a wider applicability than the method involving force measurements on small floating surface elements.