Pronunciation: [pˈʌlsɪd͡ʒˌɛt] (IPA) 
The word "pulsejet" is spelled with a silent "e" at the end, despite the fact that the "u" in "pulse" is pronounced like "uh" rather than "oo." This is because the "e" at the end indicates a "soft" "s" sound, as opposed to a "hard" "s" sound like in the word "pulseless." In IPA phonetic transcription, the word can be written as /pʌlsdʒɛt/. Pulsejets are a type of combustion engine often used in model airplanes and drones.
A pulsejet is a type of combustion engine that utilizes intermittent combustion to produce thrust. It is a simple, yet powerful, jet engine design often used in unmanned aerial vehicles, model airplanes, or as auxiliary engines in certain applications. The term "pulsejet" is derived from the principle that it operates by producing series of pulsating combustion cycles.
The operation of a pulsejet engine involves a cyclical process. It starts with an intake phase where air is drawn into the combustion chamber. This is followed by fuel injection, typically in the form of a fuel valve. Once the fuel and air mixture is ignited, it rapidly combusts, creating a high-pressure wave that ejects exhaust gases from the rearward nozzle, generating thrust. Following the exhaust phase, the engine experiences a short rest period before the next intake phase begins.
Pulsejets are known for their simplicity and lack of moving parts compared to other jet engines. This makes them relatively inexpensive and easy to manufacture. However, their simplicity comes with certain limitations, including inefficient fuel consumption and high noise levels due to the repeated explosion cycles.
While pulsejets are not widely used in modern aviation due to their drawbacks, their straightforward design and low cost make them popular in various applications. Additionally, they have been studied and experimented with for their potential use in hypersonic aircraft and space exploration vehicles, where their simplicity and ruggedness can be advantageous.
The word "pulsejet" is derived from two components: "pulse" and "jet".
1. Pulse: The term "pulse" refers to a brief, intermittent burst, impulse, or vibration. It comes from the Latin word "pulsus", which means a beating or pulse. In the context of engines, "pulse" is often used to describe the cyclic operation, alternating between combustion and exhaust phases.
2. Jet: The term "jet" refers to a high-velocity stream of fluid or gas ejected forcefully in one direction. It comes from the Old French word "jeter", meaning "to throw" or "to cast". In the case of engines, "jet" typically represents the exhaust gases expelled at high speed to generate propulsive thrust.
Combining both components, "pulsejet" describes an engine that operates by producing intermittent bursts of combustion and exhaust, creating a pulsating jet of gases.
