The principle of a small rocket under pressure
Rocket propulsion theory is the foundation of space theory. Rocket engines are a type of propulsion tool that can provide powerful thrust to enable spacecraft to achieve the necessary cosmic velocity. Their operation is based on the principle of direct reaction motion, which is particularly advantageous for high-speed navigation.
So, what is direct reaction motion?
According to Newton's laws of motion, two interacting objects always have a force and an opposing force that exist simultaneously, are of equal magnitude, and have opposite directions. Therefore, any kind of movement, broadly speaking, can be considered as an action-reaction movement. For example: one is a ship, which advances due to the action of the ship's propeller on the water, and the opposing force of the water propels the ship forward; the other is a jet engine, which gains forward momentum due to the combustion of fuel in the engine, with the expanding gasses rapidly ejecting backward, thus the engine receives a thrust in the opposite direction of the gasses' ejection.
When studying the phenomenon of thrust generation from a general perspective, there is no difference between the two types of motion mentioned above; they are both moving under the influence of the reaction force. However, when looking at the characteristics of the reaction force, there are differences between the two: In one example, the engine itself cannot cause motion; it is merely a source of energy. If there is an engine on the boat without the propeller, no matter how powerful the engine is, the boat cannot move. Therefore, in addition to the engine (the energy source), there is an intermediate mechanism between the engine and some external object (such as the water in this case), which interacts with the external object and bears the reaction force generated by it. This intermediate mechanism, which is usually called the propeller (such as the propeller in this case); in the second example, there is no intermediate mechanism, and the thrust is generated by the reaction force on the engine itself from the combustion gas. We call the type of motion in the former case indirect reaction motion, and the type of motion in the latter case direct reaction motion. Of course, there are also mixed types that coexist with direct and indirect reaction motion, such as: Turboprop engines, where part of the engine's energy is transferred to the propeller (the propeller), while another part generates the direct reaction motion of the combustion gas flow.
Jet propulsion is a form of direct reaction motion. So, what is jet propulsion? The ejection of material from a propelling object in the form of gas jets is called jet propulsion.
The material ejected by a jet propulsion system is called the propellant; an engine that uses jet propulsion to generate thrust is called a jet engine. When in motion, the interacting objects are the engine itself and the high-speed airflow that is ejected from it. The reaction force generated by the high-speed airflow acts on the engine itself, with the direction being opposite to that of the airflow, which is what creates the thrust.
Jet engines are divided into two major categories:
One is the air-jet engine, which is an engine that uses the atmosphere to generate jet streams. For example: using oxygen in the atmosphere as an oxidizer, burning fuel to produce a jet of hot gas; or heating air in a nuclear heat exchanger and then discharging it through a nozzle;
The second is the rocket engine, which is a jet engine that carries all of its propellant on board. For example, it contains oxidizers and combustibles to produce a jet of hot gases.
The thrust and velocity achieved by rocket engines far exceed those of conventional propulsion methods. This engine does not depend on the surrounding medium conditions and can operate in space environments, which ensures that the thrust generated by the engine is constant regardless of the air's ability to absorb it. This feature makes the rocket engine's flight speed much higher than that of any other type of engine. Secondly, due to the direct reaction motion, there are no intermediate mechanisms, and there are no limiting working temperature mechanisms in the main jet channels. This determines that the rocket engine has a simple structure and generates a large thrust.。

Product Name: Little Rocket

Product code: FJ901 Rocket

Size: 19*5.5*11CM