The results of an experimental study and numerical simulation of the relaxa
tion of the composition of the flow of high-temperature combustion products
in cylindrical channels with cooled and uncooled walls are presented. Prim
ary attention is given to the effect of parameters such as the channel radi
us, the oxidizer excess coefficient in the initial mixture, and the wall te
mperature on the relaxation of carbon monoxide CO and on the level of its c
oncentration at the channel outlet.