Enclosed Rocket Nozzle

Rocket engines generate enormous thrust. They overcome the gravity on hundreds of tons of weight. Most of the lifting force is generated at the nozzle. Imagine the amount of stress on them. Additionally, the nozzles are subjected to huge thermal stress. The cooling hollow mesh of a small rocket nozzle is seen on the picture. The circulating propellent cools the nozzle from overheating.

I have a radical design change for the rockets. I know that it may not be ideal. I propose the nozzle to be enclosed by the rocket casing. At the moment only the narrow part of the nozzle is connected to the rocket. In order to reduce the stress at that point, I propose the rocket casing to continue till the end of the nozzle to support it on its edges. Additionally, I propose the liquid fuel, RP1, tank to extend down to the nozzle. As a result, inner surface of the nozzle will be in contact with the fuel. The objective of this design change is to improve the regenerative cooling effect by increasing the surface area. This huge thermal contact would increase the temperature of the fuel and its tank pressure without the need for helium gas. I propose one more design change. That is to feed some of the exhaust gas from the turbopumps to the LOX tank in order maintain tank pressure without helium. 

The benefits of these design changes:

- The rocket nozzle would be supported from multiple points to reduce its mechanical stress.

- The rocket would be cooled by the liquid fuel from a much larger surface. Creating cooling channels on big nozzles is not easy. Advanced 3d designs can only be printed for small nozzles. Therefore, the nozzle design would be simplified in my design.

- No helium tank needed to pressurize the tanks.

- Rocket stage separation section covers the second stage nozzle which is much taller than the first stage. The extended enclosure negates the need for such cover and increases the fuel capacity slightly as well.

- The rockets can land directly on their bottoms which would be much stronger and has more surface area.

One major down side is. The engines would not have gimbled nozzles. At least three such rockets should be strapped together to allow directional thrust by varying the thrust of each rocket individually.

Hope to see more people experimenting with radical changes to rocket designs.