A rocket engine or simply "rocket" is a jet engine A jet engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets and pump-jets. In general, most jet engines are internal combustion engines but non-combusting forms also exist[1] that uses only propellant A propellant is a material that is used to move an object. This will often involve a chemical reaction. It may be a gas, liquid, plasma, or, before the chemical reaction, a solid mass for forming its high speed propulsive jet A jet is a coherent stream of fluid that is projected into a surrounding medium, usually from some kind of a nozzle or aperture. Jets can travel long distances without dissipating. In the Earth's atmosphere there exist jet streams that travel thousands of miles. Rocket engines are reaction engines A reaction engine is an engine which provides propulsion by expelling reaction mass, in accordance with Newton's third law of motion. This law of motion is most commonly paraphrased as: "For every action force there is an equal, but opposite, reaction force" and obtain thrust in accordance with Newton's third law Newton's laws of motion are three physical laws that form the basis for classical mechanics. They are:. Since they need no external material to form their jet, rocket A rocket or rocket vehicle is a missile, spacecraft, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of a jet of fast moving fluid exhaust from a rocket engine. Chemical rockets create their exhaust by the combustion of rocket propellant. The action of the exhaust against the inside of combustion engines can be used for spacecraft propulsion Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. However, most spacecraft today are propelled by exhausting a gas from the back/rear of the vehicle at very high speed as well as terrestrial uses, such as missiles A missile is a self-propelled projectile used as a weapon. Missiles are typically propelled by rockets or jet engines. Missiles generally have one or more explosive warheads, although other weapon types may also be used. Most rocket engines are internal combustion engines The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine the expansion of the high temperature and pressure gases, which are produced by the combustion, directly applies force to a movable component of the engine, such as the, although non combusting forms also exist.
Rocket motor is a synonymous term that usually refers to solid rocket engines. Chemical rockets are rockets powered by exothermic In thermodynamics, the term exothermic describes a process or reaction that releases energy usually in the form of heat, but also in the form of light (e.g. a spark, flame, or explosion), electricity (e.g. a battery), or sound. Its etymology stems from the Greek prefix ex- (meaning "outside") and the Greek word thermein (meaning "to chemical reactions of the propellant. Thermal rockets are rockets where the propellant is inert, but is heated by a power source such as solar or nuclear power.
Rocket engines as a group, have the highest exhaust velocities, are by far the lightest, and are the most energy efficient (at least at very high speed) of all types of jet engines. However, for the thrust they give, due to the high exhaust velocity and relatively low specific energy Specific energy is defined as the energy per unit mass. Common metric units are J/kg or, in basic SI units: m2/s2. It is an intensive property. Contrast this with energy, which is an extensive property. There are two main types of specific energy: field strength and strength of movement. Others are the gray and sievert, measures for the absorption of rocket propellant, they consume propellant very rapidly.
Contents |
unknown
Sun, 26 Jul 2009 03:07:48 GM
Russians Marketing Soviet-Era Lunar . Rocket Engine. to Americans: Russia Today has an interesting story about a possible joint US-Russian venture to produce new versions of the NK-33 . engine. , which was originally developed in the 1960 s ...
