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Pulsejets, or pulse jets are a unique type of engine that can be made with zero moving parts.
Beck Technologies is constantly striving to advance the state of the art of pulsed combustion and
pulse jet propulsion, as well as correcting the past 50 years of misinformation, and out right military
contractor propaganda, that has made its way into the educational circle, and become trapped in a
self perpetuating cycle.
Chances are if someone has heard of a pulsejet before, 90% of what they know is wrong. The 10% of
information they do know is also applied as broad over generalizations, which does not hold true for
all designs.
First developed in the early 1900's, pulsejets did not see any real use until WW2 when they were
used to propel German cruise missiles. Other countries tried to adapt the technology, but pulsejets
were quickly pushed aside by the turbojet, and fell into obscurity before any significant advances
were made.
Since the 1950's relatively little research has been done with pulsejets compared to their turbine
engine counterparts, and a lot of myths and plain misinformation have developed, and has even
been perpetuated by college engineering text books. Most have completely false information, and
everyone keeps spreading it.
The mechanical simplicity makes them very well suited for a number of applications, with virtually
no maintenance costs. Since pulsejets cost many times less than factory made turbojets, and are
much easier to make than building a jet out of a turbocharger, they are increasing in popularity as a
low cost way to get into hobby jet propulsion. They have been used to propel everything from
go-carts to bikes to boats, not to mention RC planes.
They are not only mechanically very simple, but they also have an extremely large throttle range,
high thermal energy release, and naturally low harmful emissions. Pulsejets are one of the most
efficient ways of converting fuel into heat, with some of the lowest releases of harmful emissions of
any type of engine or combustion device.
They can be designed and optimised for propulsion, thermal output, and a wide number of other
applications such as acoustic output or thermal insecticide foggers.
Pulsejets can also be made to run on fuels and material that most people don't even consider fuel.
They can run on everything from coal dust, saw dust powder, used cooking oil, to more traditional
fuels like gasoline or diesel. As we like to say, if it burns, you can probably run a pulsejet on it.
Just because pulsejets glow orange hot does not mean they are extremely inefficient. Pulsejets
have no internal moving parts, and their core gas temperature is not limited by the melting point of
high RPM turbine blades. Metals like stainless and Inconel are very good at holding in heat, and while
they may glow orange hot, only a small part of the heat is radiated away.
Turbines can only burn a fraction of the air they are able to take in and compress, if they tried to burn
all the air in the combustion chamber, the turbine blades would melt no matter how much coolant
was pumped through them. This is why military fighter jet engines have afterburner systems, the
afterburner injects additional fuel into a duct that is past the temperature sensitive turbine blades,
using up the oxygen left over in the exhaust. An afterburner system is not as efficient as combustion
in the engines combustion chamber section, and results in extremely high fuel consumption.
Although there are a number of designs such as the classical 'Lockwood' which burn through fuel
like there is no tomorrow, the design is one of the worse examples of pulsejet fuel consumption.
Even just tweaking the classical Lockwood design slightly results in much better efficiency.
Beck Technologies is constantly striving to advance the state of the art of pulsed combustion and
pulse jet propulsion, as well as correcting the past 50 years of misinformation, and out right military
contractor propaganda, that has made its way into the educational circle, and become trapped in a
self perpetuating cycle.
Chances are if someone has heard of a pulsejet before, 90% of what they know is wrong. The 10% of
information they do know is also applied as broad over generalizations, which does not hold true for
all designs.
First developed in the early 1900's, pulsejets did not see any real use until WW2 when they were
used to propel German cruise missiles. Other countries tried to adapt the technology, but pulsejets
were quickly pushed aside by the turbojet, and fell into obscurity before any significant advances
were made.
Since the 1950's relatively little research has been done with pulsejets compared to their turbine
engine counterparts, and a lot of myths and plain misinformation have developed, and has even
been perpetuated by college engineering text books. Most have completely false information, and
everyone keeps spreading it.
The mechanical simplicity makes them very well suited for a number of applications, with virtually
no maintenance costs. Since pulsejets cost many times less than factory made turbojets, and are
much easier to make than building a jet out of a turbocharger, they are increasing in popularity as a
low cost way to get into hobby jet propulsion. They have been used to propel everything from
go-carts to bikes to boats, not to mention RC planes.
They are not only mechanically very simple, but they also have an extremely large throttle range,
high thermal energy release, and naturally low harmful emissions. Pulsejets are one of the most
efficient ways of converting fuel into heat, with some of the lowest releases of harmful emissions of
any type of engine or combustion device.
They can be designed and optimised for propulsion, thermal output, and a wide number of other
applications such as acoustic output or thermal insecticide foggers.
Pulsejets can also be made to run on fuels and material that most people don't even consider fuel.
They can run on everything from coal dust, saw dust powder, used cooking oil, to more traditional
fuels like gasoline or diesel. As we like to say, if it burns, you can probably run a pulsejet on it.
Just because pulsejets glow orange hot does not mean they are extremely inefficient. Pulsejets
have no internal moving parts, and their core gas temperature is not limited by the melting point of
high RPM turbine blades. Metals like stainless and Inconel are very good at holding in heat, and while
they may glow orange hot, only a small part of the heat is radiated away.
Turbines can only burn a fraction of the air they are able to take in and compress, if they tried to burn
all the air in the combustion chamber, the turbine blades would melt no matter how much coolant
was pumped through them. This is why military fighter jet engines have afterburner systems, the
afterburner injects additional fuel into a duct that is past the temperature sensitive turbine blades,
using up the oxygen left over in the exhaust. An afterburner system is not as efficient as combustion
in the engines combustion chamber section, and results in extremely high fuel consumption.
Although there are a number of designs such as the classical 'Lockwood' which burn through fuel
like there is no tomorrow, the design is one of the worse examples of pulsejet fuel consumption.
Even just tweaking the classical Lockwood design slightly results in much better efficiency.
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A good valveless pulsejet for example, has the same, or better fuel consumption as hobby turbines,
and in some cases the more advanced valveless engines actually have lower fuel consumption than
the large, very advanced hobby turbines, and even a lot of commercial and military propulsion
turbojets.
and in some cases the more advanced valveless engines actually have lower fuel consumption than
the large, very advanced hobby turbines, and even a lot of commercial and military propulsion
turbojets.
Pulsejets also are able to be 'augmented' by placing a simple shaped duct behind the engine that
harnesses various forces in the exhaust flow, to generate more thrust with no additional fuel
consumption. In practical propulsion applications thrust augmentation typically doesn't exceed an
85% increase in thrust, but that is able to put an advanced pulsejet into the fuel efficiency range of a
turbofan jet, with no moving parts!
The short explanation of how a thrust augmenter works, is that it acts as an annular wing, generating
forward 'lift', as well as having an expansion section where cool air can mix with high temperature
exhaust gas that is still burning, to create additional expansion, and more thrust.
Even NASA has become stricken by the entrenched misinformation, as fewer and fewer people from
WWII are still alive, which was the golden age of pulsejet research and development. Today, few
people world wide have real hands on experience with more than one or two pulsejet designs. NASA
has recently taken up doing research on pulsejets and pulsed flow augmentation, and how it relates
to pulse detonation engine augmentation.
NACA the predecessor agency to NASA, made significant advances over the standard V-1 engine
design from WWII, but it all seems to have been forgotten and filed away, as they now use standard
hobby Dynajet valved engines, the same as from the 1940's, to conduct rather extensive in depth
tests.
To sum up the Dynajet's level of development, simply adding 4 holes to the fuel injector
design increases the performance by 12%. Using the same tailpipe with a different valve head of a
more advanced design can increase the thrust output 75%.
Why they use inferior engines for experiments and programs where the man hours of labor add up to
many tens of thousands of dollars is beyond me.
harnesses various forces in the exhaust flow, to generate more thrust with no additional fuel
consumption. In practical propulsion applications thrust augmentation typically doesn't exceed an
85% increase in thrust, but that is able to put an advanced pulsejet into the fuel efficiency range of a
turbofan jet, with no moving parts!
The short explanation of how a thrust augmenter works, is that it acts as an annular wing, generating
forward 'lift', as well as having an expansion section where cool air can mix with high temperature
exhaust gas that is still burning, to create additional expansion, and more thrust.
Even NASA has become stricken by the entrenched misinformation, as fewer and fewer people from
WWII are still alive, which was the golden age of pulsejet research and development. Today, few
people world wide have real hands on experience with more than one or two pulsejet designs. NASA
has recently taken up doing research on pulsejets and pulsed flow augmentation, and how it relates
to pulse detonation engine augmentation.
NACA the predecessor agency to NASA, made significant advances over the standard V-1 engine
design from WWII, but it all seems to have been forgotten and filed away, as they now use standard
hobby Dynajet valved engines, the same as from the 1940's, to conduct rather extensive in depth
tests.
To sum up the Dynajet's level of development, simply adding 4 holes to the fuel injector
design increases the performance by 12%. Using the same tailpipe with a different valve head of a
more advanced design can increase the thrust output 75%.
Why they use inferior engines for experiments and programs where the man hours of labor add up to
many tens of thousands of dollars is beyond me.
