APPARATUS FOR INCREASING THE HEAT TRANSFER TO THE APPARATUS FOR INCREASING THE HEAT TRANSFER TO THE COOLANT ON THE INSIDE OF A NOZZLE WALL OF EXPANDERCOOLANT ON THE INSIDE OF A NOZZLE WALL OF EXPANDER CYCLE ROCKET ENGINES CYCLE ROCKET ENGINES

摘要

The invention relates to an apparatus for increasing the heat transfer to the coolant on 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 boundarylayer at the nozzle wall and thereby increasing the beat transfer, the inside of the nozzle wall feeing 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.