quasi-turbine combustion engine
TRANSCRIPT
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Quasi-turbine
Document By
SANTOSH BHARADWAJ REDDY
Email: [email protected]
Engineeringpapers.blogspot.com
More Papers and Presentations available on above site
mailto:[email protected]:[email protected] -
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ABSTRACT
In this paper a rotary internal combustion engine, Quasi-turbine is discuss
this, rotary motion is generated through the combustion of the fuel, unlike the pist
converts reciprocating motion. It is a modified form of Wankel engine. This paper explains the
salient features of Quasi-turbine, its working, the combustion process involved, and the v
of applications in detail.
The peculiarity of Quasi-turbine is in possessing of four combustion chambers, all of which
participate in combustion in each revolution. That means in just two revolutions of the rotor, there are
32 strokes, out of which 8 are power strokes. It has its existence in two forms
(with carriages) and QT-SC (with out carriages). The volume of the combustion chamber depends
on the movement of the internal parts. This is the basis of the suction, compression, expansion and
exhaust processes.
The ordinary combustion processes like flame propagation, auto-ignition, HCCI cannot
burn the complete fuel because of the peculiar geometric shape of chamber. Hence
detonation, a consequence of detonation is utilized, in which radiated waves released from
detonation process will burn the fuel even at inaccessible parts. It eliminates the usage of anti-
detonating agents.
Quasi-turbine has a wide range of applications like pneumatic engines, steam e
compressors, pumps, chainsaws, air cars etc., It overcomes all the drawbacks of
engine. It overcomes the inertia of various parts like crank shaft, valves, and cams of a reciprocating
engine and improves the efficiency. It has various superiorities over Piston engine and Wankel
engine which are explained later in detail. Till now a variety of products like QT600SC, QT75SC, QT
chain saw, QT air car are manufactured and being tested.
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INTRODUCTION
At first the internal combustion engine found was a rotary combustion
namely Wankel engine. But till now the reciprocating piston engine has appeared to
operational than any other. But a rotary combustion engine developed by the improvement of Wankel
engine is now going to show better performance than the piston engine avoiding the limitations of the
original piston engine. It is Quasi-turbine.
The engine uses a four-sided articulated rotor that turns within a complex computer calculated
oval shape creating regions of increasing and decreasing volumes as the rotor turns. The Quasi-turbine
design can also be used as an air motor, steam engine, gas compressor or pump.
of burning fuel using photo-detonation, an optimal combustion mode of the future th
can not support...
HISTORY
At first the inventors found that when the turbine blades are attached one to an other in a
chain like configuration, the rotor acted as compressor for a quarter of a turn, and as engine the nextquarter of a turn... This is origin of the idea of Quasi-turbine. This was first invented by Saint-Hilaire
family and first patented in 1996.
Quasi-turbine Definition
The Quasi-turbine is a no cranksh aft rotary engine h
faces articulated rotor with a free and accessible center, rotating without vibration o
time, and producing a strong torque at low RPM under a variety of modes and fuels. The Quasi-
turbine design can also be used as an air motor, steam engine, gas compressor or pump. The Quasi-
turbine is also an optimization theory for extremely compact and efficient engine concepts.
BASIC PRINCIPLE
It is a rotary internal combustion engine having a deformable four
rotor which enables to create four different chambers inside the engine. The charge is
to enter through the inlet port into the combustion chamber. Then this charge is sub
Compression,
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Combustion and Expansion processes. Then the residual gases are sent through the exhaust port.
The same sequence of processes happens in the other three chambers. Thus we can get 8 power
strokes out of two revolutions. The power strokes in each combustion chamber will rotate the shaft
due to the peculiar geometry of the rotor.
ENGINEERING CONFIGURATION
CONSTRUCTION
It is a rotary internal combustion engine. It is either circular or el
It is constructed in two ways.
1. QT-AC (with carriages)
2. QT-SC (without carriages).
QT-AC (with carriages)
The rotor is made up of simple a mechanical linkag
deformable volumes. In this there will be four carriages. Each carriage is connected to the shaft
through a peculiar geometrical shape. The rotor turns on the inner periphery of the stator through thedumb-bell shaped linkages. It has a fixed inlet and exhaust ports. The compression and expansion
processes in the QT depend on the movement of the carriages. If the carriages move inwards the
charge is compressed and if the carriages move outwards the pressure decreases.
QT-SC (without carriages)
The rotor is made up of simple
oval shaped lobes. In this there will be four
lobes. Each lobe is interconnected to each other.
Whenever the rotor rotates on the inner periphery
of the stator the volumes of the chambers will be
changed. The stator is elliptical in shape. So that
depending on their geometry the compression and
the expansion occurs. The each combustion
chamber is sealed from the adjacent ones by
perfect ceramic coatings.
QT-AC (with carriages) & QT-SC (with out carriages)
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COMBUSTION PROCESS
PRINCIPLE
This combustion process uses detonation which is undesirable in
piston engines. Because of the detonation short pressure pulse is created. This creates a black
body type laser like radiation. Here the combustion is just like a paper burning under a focal lens
projected by sun light. The major thing here is the photons or black body waves released from the
process of detonation propagate through all the parts of combustion chamber and lead to complete
combustion and hence called Photo-detonation.
REQUIREMENTS
The combustion should be much faster in the sense that 8 combustion processes are to
be completed in two revolutions.
As the combustion chamber included b/n two carriages or lobes is peculiar, the combustion
process used should be able to burn the fuel even at inaccessible parts.
As there are 8 intake strokes per two revolutions the fuel required for combustion should bemuch less.
PROCESS
As the ordinary combustion processes like flame propagation, autoignition, H
cannot satisfy the above requirements there is a need to introduce a special process known as Photo-
detonation. This process can be easily understood as a paper burning under a focal lens projected by
sun light. This is so because the waves persisting of photons energy when focuse
high intensity at the tip and thereby the temp rises at that end. It can be easily understood as the
letter i. In general we will use anti-detonation additives to absorb the shock waves of detonation.
But these are UN necessary here because these waves are necessary for the photo-detonation mode of
combustion.
The sequence of process of photo-detonation proceeds as follows.
Ordinary wave front combustion (also called Deflagration)
Auto lit (hot spot triggering still deflagration)
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Thermo lit (a very irregular process where several little pocket of mixture lit spontaneously
,but here inter-region goes deflagration)
Photo-detonation (there the compression temperature is high enough to generate
high concentration of black body radiation increasing as the power 4 of the temperature).
ADVANTAGES
Detonation in the QT occurs rapidly at top dead center. In the diesel engine, ignition of the
injected fuel occurs somewhat after TDC, so it is progressiv
mechanically protect the piston. The QT's power stroke is therefore somewhat longer "with
early and late mechanical energy conversion" and the exhaust somewhat cooler, which also
implies a more efficient engine.
This combustion process eliminates the usage of anti-knocking additives.
The Quasi-turbine (unlike the diesel) is therefore a clean homogeneous combustion engine.
It has virtually no emissions other than the standard products of combustion, e.g., CO2 and
H2O.
WORKING
It is a rotary internal combustion engine having a deformable four faced rotor which
enables to create four different chambers inside the engine. In each combustion chamber the normal
four strokes happens.
In QT-AC (with carriages) the movement of the carriages inwards and outwards.Let us
observe the four strokes in a single combustion chamber which are shown with arrows in the
following figure.
Suction Compression
Suction:
the
The charge (fuel and air mixture) is allowed to enter the combustion chamber because of
Outward movement of the carriages leading to reduction of pressure than the atmospheric pressure.
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Compression:
The charge is compressed due to the inward movement of the carriages to a high pressure
and temperatures because of high compression ratios.
Expansion:
The high thermal energies released in the combustion chamber
into mechanical energies generating mechanical forces which pushes the carriages outw
there by rotating the rotor.
Exhaust:
Because of the inward motion of the carriages the exhaust is sent out through exhaust ports.
In QT-SC (with out carriages) the movement of the articulated lobed rotor in a vowel
shaped
stator creates varied volumes of the chamber.
Suction:
The charge (fuel and air mixture) is
allowed to enter the combustion chamber
because of the increased volume.
Compression:
The charge is compressed due to the
pressing of a lobe against the stator.
Expansion:
The high thermal energies released in the combustion chamber
into mechanical energies generating a mechanical force which pushes the lobes generatin
rotary torque.
Exhaust:Because of the pressing of a lobe against the stator, all the exhaust is se
through exhaust ports.
LIMITATIONS OF PISTON ENGINE COMPARED TO QUASI-TURBINE
1. The 4 stroke piston makes positive torque only 17% of the time and drag 83% of the time.
2. The duration of the piston rest time at top and bottom are unnecessarily too long which increases
the heat transfer to the engine block, thus reducing engine efficiency.
3. Some times during the negative valve overlap some fresh charge may escape with exhaust gases.
4. The need for a complex set of valves and camshaft uses substantial power.
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5. The valves inertia is a serious limitation to the engine revolution.
Quasi-turbine
IMPROVEMENTS OF QUASI-TURBINE OVER WANKLE ENGINE
The Wankel engine shaft turns at
The Quasi-turbine rotor and main shaft turns at the same speed.
The Wankel engine has a dead times. A complete rotor (not shaft) revolution is composed of three
relaxation strokes of 90 degrees each, separated by a 30 degre
The Quasi-turbine strokes are consecutive, with no dead time, allowing continuous combustion by
flame transfer.
The Wankel needs 2 sparkplugs because of the gas rolling effect and the
combustion chamber
shape. One sparkplug is sufficient in Quasi-turbine.
The Wankel engine is a "rotating piston engine" that is subject to a constan
vibration. The Quasi-turbine has a fixed center of gravity during rotation, and is a true zero
vibration engine
(like the turbine)
Due to its geometry, the Wankel exhaust and intake ports overlap extensively,
much before the expansion stroke is over, and closing much after the intake st
begun. The Quasi-turbine does not impose such a wide overlap detriment to efficiency.
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QUASI TURBINE APPLICATIONS
PNEUMATIC QUASITUBINE
Quasi-turbine can be effectively used as a
engine. Pneumatic systems have a big advantage: they are cheap a
impractically expensive battery maintenance. If we send compressed air into the QT it can generate
driving torque effectively. If we send compressed air into the reciprocating engine it can work but it
has several problems with the inertia of flywheel, crank shaft, valves and cams. But QT has no
such problems. Tests are being done on QT with Nitrogen, Hydrogen etc., It is also tested for
locomotives. A car using pneumatic QT is also found.
STEAM QUASI-TURBINE
At now steam engines are obsolete because of their inh
low efficiency and bulkiness. But the present QT can also be used to generate the torque with steam
with a theoretical efficiency of 50%. It is also proposed for locomotive engine
conventional steam turbines require very high pressure in order to generate the high flow speedpermitting the turbine to be
efficient. This is not the case with the QT which is very efficient at all pressures, all
load levels and all RPM, and can produce substantial power. The QT greatly reduce
station construction and operation cost, improves substantially the risk and safety level.
COMPRESSORS
The Quasi-turbine has 2 intakes and 2 exits related
distinct circuits. Each circuit can be used to compress gas. The Quasi-turbine is a
displacement compressor, and does not make use of aero- or h
consideration. Reciprocal compressor reverses the flow while they compress, which is a
inertia, turbulent and heat generation limitation for high rpm. Because the flow is
and nearly unidirectional, QT is much less sensitive to flow reversal, turbulence and heat generation,
which improves it efficiency.
PUMPS
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In the pump mode, a Quasi-turbine driven by an external motor has
2 intakes and 2 exits related to 2 quasi-distinct circuits. Each circuit can be used as vacuum or
pressure pump, for compressible or non-compressible fluids. The Quasi-turbine is a pos
displacement pump, and does not make use of aero- or hydro-dynamic flow consideration.
PRODUCTS OF QUASI TURBINE
Pneumatic Quasi-turbine
600 & 75 indicates
the combustion chamber
volume
QT600SC
QT75SC
Steam Quasi-turbine
QT50SC
Quasi turbine Chain Saw
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Air Car : Uses QT 600 SC engine
ADVANTAGES
Because it does not have internal accessories to drive, like the piston cam shaft and valve
train, additional energy is available to the end users.
Because the Quasi-turbine can be of large size, it is an efficient alternative to
for efficient energy conversion (steam) in electricity or from co-generation.
Because the Quasi-turbine (AC model with carriages) has the potential to r
detonation mode, it will not have the low power penalty of the Otto cycle,
provide a 50% energy saving in transportation application (much superior to hybr
concepts).
Fly wheel, eccentric are not required unlike Wankel engine.
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Atmospheric gas pollution - Having a reduced combustion confinement time, the NOx are are
produced in lower
concentration.
Noise pollution - Having
4 combustions per
rotation, and due to a
longer gas relaxation
chamber, noise is reduced
by a factor of 20 or more!
The Quasi-turbine is a
vibration free engine
Oil free engine -
Lubrication is source of
pollution. The Quasi
- turbine has potential to
be an oil free engine.
DISADVANTAGES
Photo-detonation is not compatible with gaseous fuels like Hydrogen, C NG etc,
Sealing of the combustion chambers is difficult.
Construction of Quasi turbine is a job with difficulty.
CONCLUSIONS
Quasi-turbine is a rotary internal combustion engine having four chambers whose
shape varies according to the movement of the internal parts
QT has two varieties QT-AC (with carriages), QT-SC (with out carriages)
The combustion process is Photo Detonation which is a consequence of detonation
There is no necessity for anti-detonation agents and lubricants
The inertia of crank shaft, valves, cams etc., is avoided because direct rotary
is generated
Quasi-turbine is multi-fuel compatible (gasoline, diesel, H2, CNG etc.,)
All the disadvantages of Wankel rotary engine are eliminated
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It has a wide range of applications such as Pneumatic Quasi-turbine, Steam Quasi-
turbine, compressors, pumps etc.,
It can generate higher torque even at low RPMs
REFERENCES
[1] http://web.mit.edu/newsoffice/tt/2003/mar05/hydrogen.html
[2] Scientific American of June 2002A Low-Pollution Engine Solution - New
sparkless- ignition automotive engines gear up to meet the challenge of cleaner combustion
[3] http://www.llnl.gov/str/Westbrook.html
[4] http://www.vok.lth.se/CE/research/HCCI/i_HCCI_uk.html
[5] www.qausiturbine.com
Document By
SANTOSH BHARADWAJ REDDY
Email: [email protected]
Engineeringpapers.blogspot.comMore Papers and Presentations available on above site
mailto:[email protected]:[email protected] -
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