NONEQUILIBRIUM BOUNDARY-LAYER OF POTASSIUM-SEEDED COMBUSTION PRODUCTS

Results are reported from numerical modeling and experimental study of a chemically reacting boundary layer, formed on a body inserted into a stream of potassium-seeded combustion products of gaseous hydrocarbo n fuels. The numerical model developed in previous work is modified to incorporate current data on potassium chemical kinetics. The temperat ure and potassium atom number density profiles are measured across the boundary layer formed on a cylindrical specimen of Al2O3 dense cerami cs by flow of combustion products of a propane-air mixture. The numeri cal results are compared with present experimental data as well as tho se available from the literature. The comparison is carried out for a broad range of experimental conditions including the postflame burned- gas region, and the boundary layers on a cylinder and on a flat plate. It provides verification of the proposed model, revision of the rate constants of some reactions of potassium-containing species, and suppo rts the value of potassium superoxide dissociation energy of 247 kJ/mo l.