I Built the FIRST VENTURI ROCKET ENGINE

Quick Overview

The creator successfully built and tested a functional hybrid rocket engine nozzle using a 3D-printed aerospike design, proving that the design works effectively when fed with a proportional mix of liquid (isopropyl alcohol) and gaseous (propane) propellants, despite the challenges of the custom-machined injector being difficult to throttle.

Key Points: The creator successfully tested a custom-built hybrid rocket engine featuring a 3D-printed aerospike nozzle design. The propellants used were isopropyl alcohol (liquid fuel) and propane (gas oxidizer), mixed at a ratio intended to create a 'rocket fuel' that burns like rocket fuel. The initial test of the custom-machined injector resulted in poor combustion quality, leaving residue and a blast that looked like 'molten sugar' (05:16). The creator then switched to a 3D-printed nozzle design, which performed significantly better, although the final test with the new nozzle produced a purple flame, indicating an issue with the fuel-to-oxidizer ratio. The narrator admits to lying about the impossibility of controlling the thrust on hybrid rockets, noting that the design allows for throttling the fuel flow (03:04). The video heavily features the use of an Onshape CAD simulation to visualize the fluid dynamics (Venturi effect) within the injector, showing how the high-pressure air draws in the lower-pressure liquid fuel. The creator used a $10 stainless steel 3D-printed nozzle (purchased from JLCPCB) as a superior alternative to the initial, poorly performing machined injector.

Context: The video documents the process of designing, manufacturing, and testing a custom hybrid rocket engine injector, contrasting the performance of a traditional machined injector with a new 3D-printed aerospike design. The creator uses both physical tests (igniting small amounts of propellant) and CFD simulations in Onshape to validate the fluid dynamics principles, specifically the Venturi effect, which is crucial for properly atomizing and mixing the liquid fuel (isopropyl alcohol) and gaseous oxidizer (propane).