APPARATUS FOR CONTROLLING THE HEAT TRANSFER TO THE NOZZLE WALL OF EXPANDER CYCLE ROCKET ENGINES

摘要

The invention relates to an apparatus for increasing the heat transfer to the coolant at the inside of a nozzle wall provided with coolant channels of expander cycle rocket engines. To achieve this the invention proposes that, to disturb the boundary layer at the nozzle wall and thereby increasing the heat transfer, the inside of the nozzle wall facing the flame has a particularly chosen increased surface roughness of such a magnitude that it penetrates the viscous sub-layer of the boundary layer at the nozzle wall.