Rocket engines are undeniably cool. Experiencing the roar, seeing the fire, and watching the rocket blast off into the sky… what else can you ask for? Well, for [NightHawkInLight], a transparent rocket body is the answer.
Based on previous work by [Applied Science], he uses an acrylic rod as the rocket body and as the fuel. Bring a flame into the acrylic, apply oxygen from a canister at the other end of the body and voilà! The rocket engine starts nicely, and even better, the intensity of the burn can be controlled via the amount of oxygen provided.
The construction is straightforward, just drill a hole in the acrylic rod, tap a thread at one end, and attach a brake line that goes to the oxygen canister. As he explains, in solid rocket engines the fuel and oxidizer are mixed together. A typical recipe in amateur rocketry, known as rocket candy, is a mixture of sugar (as the fuel) and potassium nitrate (as the oxidizer). In a hybrid rocket engine like this, the fuel and the oxidizer are separated from each other and they only mix in the combustion chamber. In this case, the combustion chamber is the fuel itself!
While this rocket engine may not very efficient nor produce a large thrust, it is definitely a great attention-getter. [NightHawkInLight] did a great job with this video as it has great educational value for those interested in rocketry. Other ways of building rocket engines at home include this PVC pipe version, or even a 3D printed one.