Rocket fuel: varieties and composition

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Solid rocket fuel is a solid substance (a mixture of substances) that can burn without air and at the same time release a lot of gaseous compounds heated to a high temperature. Such compositions are used to create jet thrust in rocket engines.

Rocket fuel is used as an energy source for rocket engines. In addition to solid fuel, there are also gel-like, liquid and hybrid counterparts. Each type of fuel has its advantages and disadvantages. Liquid fuels are single-component and two-component (fuel + oxidizer). Gelled fuels are compositions thickened to a gel state with the help of organic acids. Hybrid fuels are systems that include a solid fuel and a liquid oxidizer.

The first varieties of rocket fuel were precisely solid. As a working substance, gunpowder and its analogues were used, which were used in military affairs and to createfireworks. Now these compounds are used only for the manufacture of small model rockets, as rocket fuel. The composition allows you to launch small (up to 0.5 m) rockets several hundred meters in height. The engine is a small cylinder. It is filled with a solid combustible mixture, which is ignited by a red-hot wire and burns for only a few seconds.

Solid-type rocket fuel most often consists of an oxidizer, a fuel, and a catalyst to maintain stable combustion after the composition has ignited. In the initial state, these materials are powdery. To make rocket fuel out of them, it is necessary to create a dense and homogeneous mixture that will burn for a long time, evenly and continuously. Solid rocket engines use: potassium nitrate as an oxidizer, charcoal (carbon) as a fuel, and sulfur as a catalyst. This is the composition of black powder. The second combination of materials that are used as propellants are Berthollet s alt, aluminum or magnesium powder, and sodium chlorate. This composition is also called white powder. Solid combustible fillers for military missiles are divided into ballistic (nitroglycerin compressed gunpowder) and mixed, which are used in the form of channel blocks.

Solid rocket engine works as follows. After ignition, the fuel begins to burn at a predetermined rate, ejecting a hot gaseous substance through a nozzle, which provides thrust. Fuel in the engineburns until it's gone. Therefore, it is impossible to stop the process and turn off the engine until the filler burns out to the end. This is one of the serious disadvantages of solid fuel engines compared to other analogues. However, in real space ballistic launch vehicles, solid propellant materials are used only at the initial stage of flight. In the following stages, other types of rocket fuel are used, so the shortcomings of solid propellant compositions do not pose a significant problem.