Pulsed rocket motors
Encyclopedia
A pulsed rocket motor is typically defined as a multiple pulse
solid propellant
rocket motor. This design
overcomes the limitation of solid propellant motors that they cannot be easily stopped and reignited. The pulse rocket motor allows the motor to be burned in segments (or pulses) that burn until completion of that segment. The next segment (or pulse) can be ignited on command by either an onboard algorithm
or in pre-planned phase. All of the segments are contained in a single rocket motor case as opposed to staged rocket motors.
The pulsed rocket motor is made by pouring each segment of propellant separately. Between each segment is a barrier that prevents the other segments from burning until ignited. At ignition
of a second pulse the burning of the propellant generally destroys the barrier.
The benefit of the pulse rocket motor is that by the command ignition of the subsequent pulses, near optimal energy management
of the propellant burn can be accomplished. Each pulse can have different thrust level, burn time, and achieved specific impulse depending on the type of propellant used, its burn rate, its grain design, and the current nozzle throat diameter.
The Chinese People's Liberation Army Air Force
has begun deployment of the PL-12 two-pulse air-to-air missile..
Pulse
In medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...
solid propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
rocket motor. This design
Design
Design as a noun informally refers to a plan or convention for the construction of an object or a system while “to design” refers to making this plan...
overcomes the limitation of solid propellant motors that they cannot be easily stopped and reignited. The pulse rocket motor allows the motor to be burned in segments (or pulses) that burn until completion of that segment. The next segment (or pulse) can be ignited on command by either an onboard algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
or in pre-planned phase. All of the segments are contained in a single rocket motor case as opposed to staged rocket motors.
The pulsed rocket motor is made by pouring each segment of propellant separately. Between each segment is a barrier that prevents the other segments from burning until ignited. At ignition
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
of a second pulse the burning of the propellant generally destroys the barrier.
The benefit of the pulse rocket motor is that by the command ignition of the subsequent pulses, near optimal energy management
Energy management
Energy Management is a degree offered by the University of Oklahoma's Michael F. Price College of Business. The OU degree program was the first of its kind, emerging in 1958 as the Petroleum Land Management program before becoming the Energy Management program in 1999.It is business-specific, with...
of the propellant burn can be accomplished. Each pulse can have different thrust level, burn time, and achieved specific impulse depending on the type of propellant used, its burn rate, its grain design, and the current nozzle throat diameter.
The Chinese People's Liberation Army Air Force
People's Liberation Army Air Force
The People's Liberation Army Air Force is the aviation branch of the People's Liberation Army, the military of the People's Republic of China...
has begun deployment of the PL-12 two-pulse air-to-air missile..
See also
- Pulse jet enginePulse jet engineA pulse jet engine is a type of jet engine in which combustion occurs in pulses. Pulsejet engines can be made with few or no moving parts, and are capable of running statically....
, a very simple jet engineJet engineA jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
which used ignited "pulses" of gasGasGas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
or atomized fuel for propulsion. - Nuclear pulse propulsionNuclear pulse propulsionNuclear pulse propulsion is a proposed method of spacecraft propulsion that uses nuclear explosions for thrust. It was first developed as Project Orion by DARPA, after a suggestion by Stanislaw Ulam in 1947...