ramjetswhere

The term “ramjetswhere” does not correspond to a recognized concept in aerospace engineering. If you meant ramjets, this article provides a concise overview of that propulsion type.

Ramjets are a form of air-breathing jet propulsion that relies on the forward speed of the vehicle to compress incoming air. Unlike turbojets, ramjets contain no rotating compressor or turbine; they need the vehicle to be already moving at substantial speed before thrust is generated. A ramjet's core consists of an inlet to decelerate and capture air, a combustion chamber where fuel is burned with the compressed air, and a nozzle that accelerates the exhaust for thrust.

Operation and performance: Ramjets are most efficient at high subsonic to hypersonic speeds, typically at speeds where the intake can provide substantial compression without heavy machinery. They cannot start from rest and require a booster or another propulsion system to reach operating speed. Fuel is usually hydrocarbon-based; combustion must be stabilized within the chamber. The absence of rotating parts makes ramjets simple and lightweight, but efficiency falls at low speeds and in thin air at high altitudes.

Applications and limitations: Ramjets have been used in missiles and experimental aircraft, and as boost stages for space launch systems. They deliver high thrust in their design speed range but offer limited performance outside that range, necessitating hybrid propulsion solutions. Precision inlet design and materials are critical due to high temperatures in the combustion process.

History: The concept was proposed in the early 20th century by René Lorin, who coined the term ramjet. Practical ramjets were pursued in the mid-20th century and continue to influence high-speed propulsion research, including related scramjet work.

If you intended a different term, please clarify.