STEM Rocket 2 – How to design and build a rocket engine. HOW A ROCKET WORKS A rocket moves forward by ejecting gases backward, similar to a leaky balloon. But instead of air, a rocket ejects hot gases produced by burning a mixture of fuel and oxygen. WHAT’S INSIDE A ROCKET? VIDEO – How a rocket works HOW TO DESIGN AND BUILD A ROCKET ENGINE Components of a rocket engine To build a rocket engine, we need to determine the following dimensions:The throat diameter Dt.The nozzle exit diameter De.The combustion chamber diameter Dc.The combustion chamber length Lc.The combustion chamber wall thickness TwThe water flow gap.The diameter of the fuel injection holes (df).The diameter of the oxygen injection holes (do). The calculation formulas can be found in this document:How to design, build and test small liquid-fuel rocket engines FABRICATIONVIDEO – Building a Liquid rocket engine! – I built a bipropellant rocket engine as a student engineer!