The correct spelling of the word "pulse jets" is /pʌls dʒɛts/. The first part of the word, "pulse," is spelled with a 'u' as it represents the short /ʌ/ sound. The second part, "jets," is spelled with a 'j' as it represents the /dʒ/ sound. The pulse jet is an engine that works by emitting a series of combustions, and it is commonly used in model aircraft and fireworks. However, pulse jet engines are also being tested for use in larger aircraft as well.
Pulse jets refer to a type of jet engine in which propulsion is achieved by the alternating compression and expansion of air or other gases within a combustion chamber, which creates intermittent bursts or pulses of engine thrust.
Within a pulse jet, the operating principle relies on the rapid combustion of fuel to produce high-pressure gases that are expelled from the exhaust, generating a propulsive force. This is accomplished through a series of cycles where an intake valve opens to allow the entrance of air, followed by the injection of fuel and its ignition, causing a rapid increase in pressure. This high-pressure air is then expelled from the engine, creating a period of thrust. Subsequently, the valve closes, and the process repeats, resulting in subsequent pulses or bursts of propulsion.
Pulse jets are notable for their simplicity and lack of moving parts compared to traditional jet engines. This simplicity leads to reduced manufacturing and maintenance costs. However, their efficiency may be lower than other types of jet engines, and they tend to have limited overall power output.
These engines have been applied in various settings, including military applications, such as small drones or target drones, and experimental aircraft. They are also found in heating and cooling systems, as well as industrial processes that require high-temperature air or gas flows.
The word "pulse jets" has an interesting etymology that can be traced back to its Latin roots.
The term "pulse" comes from the Latin word "pulsare", which means "to drive, strike, or beat". It later evolved to "pulsus", meaning "a beating or rhythmical motion".
On the other hand, "jets" originates from the Latin word "jactare", which means "to throw or hurl". This term evolved to "jactus", meaning "a throw or a casting".
Combining these Latin roots, the term "pulse jets" essentially captures the essence of the technology behind this type of propulsion. "Pulse" refers to the intermittent combustion occurring in these engines, producing a series of pulses or rapid beats. Meanwhile, "jets" signifies the forceful expulsion of gases that propels the engine forward.