Quasiturbine
Encyclopedia
Pistonless rotary engine
A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons...
using a rhomboidal rotor whose sides are hinged at the vertices. The volume enclosed between the sides of the rotor and the rotor casing provide compression and expansion in a fashion similar to the more familiar Wankel engine
Wankel engine
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
, but the hinging at the edges allows the volume ratio to increase. Unlike vane pumps, which vane extension is generally important and against which the pressure acts to generate the rotation, the Quasiturbine contour seals have a minimal extension and the rotation does not result from pressure against these seals.
Patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
s for the Quasiturbine (in the most general AC concept with carriages) are held by the Saint-Hilaire family of Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
. As well as an internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
, the Quasiturbine has been proposed as a possible pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
design, and a possible Stirling engine
Stirling engine
A Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work....
. It has been demonstrated as a pneumatic engine using stored compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
, and as a steam engine
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
.
There are at least four proposed designs:
- Two-port with carriages, suitable for use as an internal combustion engineInternal combustion engineThe internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
. - Four-port without carriages, suitable for use as a pneumatic or hydraulicHydraulic machineryHydraulic machines are machinery and tools that use liquid fluid power to do simple work. Heavy equipment is a common example.In this type of machine, hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders and which becomes pressurised according to...
engine, steam engineSteam engineA steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
or pumpPumpA pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
. - Two-port without carriages, a conceptual design which is hoped to combine some of the advantages of the existing two- and four-port prototypes.
- Another conceptual design using a fixed charge of gas, with no ports and without carriages, as a Stirling engineStirling engineA Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work....
. (But not yet referring Malone engineMalone engineThe Malone engine is a liquid-based engine invented by J.F.J Malone of Newcastle, England. The engine used high temperature water as its working fluid, and was therefore also referred to as the Hot Water Engine. Malone's first 50 hp prototype was completed in 1925, and used coal to heat high...
in spite of similar function to Stirling engine)
The main problems with this design are
- it has far more 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....
than the Wankel engineWankel engineThe Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that... - it has never been shown to work as an internal combustion engine
- for all other possible uses there are many other designs that are more reliable and function more efficiently
Two-port with carriages
The earliest Quasiturbine design used a three-wheeled carriage (FrenchFrench language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
chariot, hence avec chariots or AC for with carriages) to support each vertex of the rotor. The wheels of these four carriages, making twelve wheels in total, ran around the periphery of the engine chamber.
A prototype of an internal combustion engine to this design was constructed, and enthusiastically reviewed in European Automotive Design
European Automotive Design
European Automotive Design is a magazine targeting as its readership those involved in the final design of automobiles manufactured in Europe....
magazine September, 1999. The prototype was turned by an external engine for 40 hours.
However, ignition with fuel was never achieved. If it was attempted no results were ever released, and development work on this design was suspended.
Advantages
- Cylinder ports in place of valves reduce the number of moving parts, in common with the Wankel engineWankel engineThe Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
and some two stroke engines. - The carriages keep the seals almost perpendicular to the cylinder walls, in contrast to the Wankel engine where the angle varies plus and minus 60°.
- The rotor can be designed so its centre of gravity remains stationary or nearly so, minimising vibration.
- Sixteen strokes per revolution of the rotor, as opposed to twelve for a single-rotor Wankel engine and two for a revolution of the crankshaft of a single-cylinder single-acting piston engine.
Photo-detonation
The two-port design with carriages was proposed to make possible a new and superior mode of combustion, termed photo-detonation by the Quasiturbine inventors. This resembles detonationDetonation
Detonation involves a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations are observed in both conventional solid and liquid explosives, as well as in reactive gases...
, as used in the Bourke engine
Bourke engine
The Bourke Engine was designed by Russell Bourke in the 1920s, as an improved two-stroke engine. Despite finishing his design and building several working engines, the onset of World War II, lack of test results, and the poor health of his wife compounded to prevent his engine from ever coming...
, akin to knocking and pinging undesirable in common internal combustion engines. , no research has been published supporting this claim. A related idea that flame transfer would be possible through special ports is similarly unsupported.
Four-port without carriages
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
. This is also the design proposed for use as a pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
, and particularly as a supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
.
This design uses redesigned blades, longer than those for a similar sized housing of the first type owing to the absence of the carriages, and lacking the distinctive crown contour. Only the basic rotor geometry is common with the earlier design.
A pneumatic engine of this design was demonstrated powering a go-kart in November 2004, and another powering a small car in September 2005, both vehicles using stored compressed air to power the engine. a pneumatic chain saw driven by an air hose from a conventional external compressor is under development.
With a suitably redesigned housing to allow for thermal expansion, the same rotor design has been demonstrated as a steam engine.
Another potential variation of this design uses the two sets of ports independently, one as an engine and the other as a pump, thus potentially integrating the functions of a pump and its driving motor in one shaftless unit. One restriction of this usage is that the two fluids must be similar; It would not be possible for example to drive an integrated air pump with hydraulic fluid, as the rotor design is significantly different. no prototype of this variation has been demonstrated.
Advantages
- Fewer moving parts than most engines (including of course the Quasiturbine design with carriages).
- Absence of valve gearValve gearThe valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle...
required by many other forms of steam and pneumatic engines.
- Absence of valve gear
- Little vibration.
- High power-to-weight ratioPower-to-weight ratioPower-to-weight ratio is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement of actual performance of any engine or power sources...
. - Possibility of integrated turbo-pump and turbo-expander configurations.
Two-port without carriages
This third design combines aspects of the first two. this design is conceptual only. It has not been built, but is used for purposes of illustration. If built it would not support photo-detonation.Many other designs are possible within the patented Quasiturbine model, with or without carriages and with differing numbers of ports. , which design will be used for further work on the internal combustion version has not been announced.
History
The Quasiturbine was conceived by a group of 4 researchers, led by Dr. Gilles Saint-Hilaire, a thermonuclear physicistPhysicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, and consisting of members of his immediate family. The original objective was to make a turbo-shaft turbine
Turbine
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...
engine where the compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
portion and the power portion would be in the same plane
Plane (mathematics)
In mathematics, a plane is a flat, two-dimensional surface. A plane is the two dimensional analogue of a point , a line and a space...
. In order to achieve this, they had to disconnect the blades from the main shaft, and chain them around in such a way that a single rotor acts as a compressor for a quarter turn, and as an engine the following quarter of a turn.
The general concept of the Quasiturbine was first patented in 1996. Small pneumatic and steam units are available from the patent holders for sale or hire for research, academic training and industrial demonstration, as is a book (largely in French) describing the concepts and development of the design. Demonstrations have been done on an Air Gokart in 2004, on « APUQ Air Car » in 2005, on the University of Connecticut « Brash Steam Car » in 2010, and other products (Chainsaw and generator).
The patent holders have announced that they intend to make similar internal combustion prototypes available for demonstration.
See also
- Compressed air engine
- Compressed air vehicle
- Pistonless rotary enginePistonless rotary engineA pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons...
, which discusses general advantages of rotary engines and comparisons between Quasiturbine, Wankel and orbital (Sarich) engines.
External links
- Quasiturbine official site.
- How Quasiturbine Engines Work from HowStuffWorksHowStuffWorksHowStuffWorks is a commercial edutainment website that was founded by Marshall Brain with the goal of giving its target audience an insight into the way in which many things work. The site uses various media in its effort to explain complex concepts, terminology and mechanisms, including...
. - University of Connecticut « Brash Steam Car » Video.
- Quasiturbine entry on INISINISINIS may refer to:*International Nuclear Information System*Iraqi National Intelligence Service*iNiS*Institut national de l'image et du son*Irish Naturalisation and Immigration Service...
at International Atomic Energy AgencyInternational Atomic Energy AgencyThe International Atomic Energy Agency is an international organization that seeks to promote the peaceful use of nuclear energy, and to inhibit its use for any military purpose, including nuclear weapons. The IAEA was established as an autonomous organization on 29 July 1957...
. - 2006 Pneumatic Demo Quasiturbine Chainsaw.
- 2011 Oregon Steam-up Demo Quasiturbine Steam.