Pulse Ejector Thrust Augmentor
Encyclopedia
A Pulse Ejector Thrust Augmentor or PETA is a proprietary pulse jet engine
developed by Boeing
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The Boeing PETA design embeds the pulse jet inside a thrust augmenting duct which entrains
surrounding air into the exhaust stream. This entrained air improves thrust
and cools the pulse jet.
Pulse jet engine
A 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....
developed by Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
.
The Boeing PETA design embeds the pulse jet inside a thrust augmenting duct which entrains
Entrainment (hydrodynamics)
Entrainment is the movement of one fluid by another.One fluid moving in another can push or pull the other along with it. Eductors or eductor-jet pumps are an excellent example. They are used onboard many ships to pump flooded out compartments in the event of an accident. Seawater is pumped to...
surrounding air into the exhaust stream. This entrained air improves thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....
and cools the pulse jet.
Advantages
- A PETA engine would be advantageous in a vertical take-off and landingVTOLA vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...
(VTOL) aircraftAircraftAn aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, with the ability to provide upward thrust and thus decouple vertical and axial movement of the aircraft. - The designers claim PETA is insensitive to sand and small debris.
- The engine's thrust augmenters can be incorporated as load bearing structures in the aircraft's superstructureSuperstructureA superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships...
, thus reducing overall weight. - The design features no moving parts, which the creators claim increases reliability compared to conventional engines with moving partsMoving partsThe moving parts of a machine are those parts of it that move. Machines comprise both moving and fixed parts. The moving parts have controlled and constrained motions....
. - Multiple engines can be assembled into an arrayArrayIn computer science, an array data structure or simply array is a data structure consisting of a collection of elements , each identified by at least one index...
, allowing scalability to heavy-lifting applications. - Arranging the engines in an array allows for distributed, highly redundantRedundancy (engineering)In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe....
thrust, thus increasing reliability.