Design changes

I've been offered to 3D print the engine in copper using a DMLS printer, so I will take this chance to design a regenerative cooling system. The original idea for this engine was to fit the thrust chamber inside a pipe and use water for cooling, but metal 3D printing will allow me to make small channels where the fuel will pass through and by doing this the combustion chamber will be cooled. The fuel, will be then injected into the combustion chamber to be burnt.

Figure 1.1 Rendered image of the engine

Figure 2.2 Top part of the engine where the cooling channels can be seen.