A pulse jet engine (or pulsejet) is a very simple form of internal combustion engineThe internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure, which are permitted to expand. The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement of solid parts of the engine, by acting on pistons, rotors, or even by pressing on and moving the entire ...internal combustion engine wherein the combustion occurs in pulsesIn medicine, a person's pulse is the throbbing of their arteries as an effect of the heart beat. It can be felt at the neck (carotid artery), at the wrist (radial artery), behind the knee (Popliteal artery), on the inside of the elbow (Brachial artery), near the ankle joint (Posterior Tibial artery), and a few other places. Pressure waves move through the blood vessels, which are pliable; these waves are not caused by the forward movement of the blood. When the heart contracts, blood is ejected into the aorta and ...pulses and the propulsive effort is a jet; a reaction to the rearwardRear may be used as a noun and a verb and has several meanings: *Rear (military) - the area of a battlefield behind the front line *For its meaning in agriculture, see breeding. *Rearing is when a horse stands up on his hind legs. *Rear end is the buttocks.rearward flowFlow may refer to: *Flow, another name for "flux" in physics, which is the rate at which something travels through a given cross section **In fluid mechanics, the word flow is often used to mean a complete description of the motion of a fluid. See also volumetric flow rate * flow chemistry, ...flow of hot gases.

A typical pulsejet comprises an air intake fitted with a one-way valveA check valve is a mechanical device, a valve, that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, many check valves are very small, simple, and/or cheap. ...one-way valve, a combustion chamberA combustion chamber is the part of an engine in which fuel is burned.combustion chamber, and an acoustically resonantIn physics, resonance is the tendency of a system to oscillate at maximum amplitude at a certain frequency. This frequency is known as the system's resonance frequency. When damping is small, the resonance frequency is approximately equal to the natural frequency of the system, which is the frequency of free vibrations.resonant exhaust pipe. The valving is accomplished though the use of reed valvesReed valves consist of thin flexible metal or fiberglass strips fixed on one end that open and close upon changing pressures across opposite sides of the valve much like heart valves do. They are intended to restrict flow to a single direction.reed valves or, in a valveless pulse jetA Valveless pulse jet (or pulsejet) is one of the simplest jet propulsion devices ever designed, and is the simplest form of jet engine that does not require forward motion to run continuously. Valveless pulsejets are low in cost, light weight, powerful and easy to operate. They have all the advantages (and most of the disadvantages) of conventional valved pulsejets, but without the troublesome reed valves that need frequent replacement - a valveless pulsejet can ...valveless pulse jet engine, through aerodynamicsAerodynamics (shaping of objects that affect the flow of air, liquid or gas) is a branch of fluid dynamics concerned with the study of forces generated on a body in a flow. The solution of an aerodynamic problem normally involves calculating for various properties of the flow, such as velocity, pressure, density, and temperature, as a ...aerodynamics. Fuel in the form of a gas or liquid aerosol is either mixed with the air in the intake or injected into the combustion chamber. Once the engine is running it requires only an input of fuel, but it usually requires forced air and an ignition method for the fuel-air mix. Once running, the engine is self-sustaining.