Looking at the Big Picture

The objective of a rocket engine is to apply acceleration by expelling burned gas with high velocity and thereby move the rocket due to the conservation of momentum. When each section of a rocket designed independently, this big picture is lost. The latest successful rocket engines vaporize the liquid propellent using the heat exchange over the hot parts of the engine then burn it to run the turbopump that pushes the gaseous propellent to pre-burner which heats it up to auto ignition temperature by burning some of it. Finally, hot propellent is burned in the combustion chamber and exhausted from the rocket via the nozzle. Highly pressured burned gas if directly ejected would expend dramatically on reaching the low pressure outside. The gases moving horizontally wouldn’t contribute to the vertical momentum of the rocket. That’s why large bell-shaped nozzles are used to equalize the pressure and align the gasses movement with the rocket’s direction.

The single nozzle design I had proposed earlier is a radical design that may never work. But the idea behind is, to increase the heat exchange surface for the propellent to reach auto ignition temperature with the need for a pre burner. More importantly allow more time for the fuel to burn along the long thin combustion chamber. Current combustion chambers are spherical and require very high pressure to increase the burn efficiency because the fuel does not have much time to burn properly. On the other hand, long tubular combustion chamber would have much lower pressure on the upper combustion zone, but would be much longer and give the fuel more time to burn completely. This lower pressure but efficient burning design will reduce the size of the nozzle which gets very big for the vacuum.

I am trying to push with extreme ideas to inspire people to think outside of the box. We have ambition to go to Mars and beyond, yet we couldn’t come up with a radical design change for the rocket.