Quasiturbine Future Engine

Quasiturbine is an engine, which could be widely used with in few years in many applications instead of reciprocating engines in automobiles.

In the basic single rotor Quasiturbine engine, an oval housing surrounds a four-sided articulated rotor which turns and moves within the housing. The sides of the rotor seal against the sides of the housing, and the corners of the rotor seal against the inner periphery, dividing it into four chambers. Contrary to the Wankel engine where the crankshaft moves the rotary piston face inward and outward, the Quasiturbine rotor face rocks back and forth in reference to the engine radius, but stays at a constant distance from the engine center at all time, producing only pure tangential rotational forces. Because the Quasiturbine has no crankshaft, the internal volume variations do not follow the usual sinusoidal engine movement, which provides very different characteristics from the piston or the Wankel engine.

As the rotor turns, its motion and the shape of the housing cause each side of the housing to get closer and farther from the rotor, compressing and expanding the chambers similarly to the "strokes" in a reciprocating engine. In the Quasiturbine engine, the four strokes of a typical cycle de Beau de Rochas (Otto cycle) are arranged sequentially around a near oval, unlike the reciprocating motion of a piston engine. However, whereas a four stroke cycle engine produces one combustion stroke per cylinder for every two revolutions, i.e. one half power stroke per revolution per cylinder, the four chambers of the Quasiturbine rotor generate four combustion "strokes" per rotor revolution; this is eight times more than a four-stroke piston engine.
A Family of Devices
Because the Quasiturbine is defined by a set of 7 geometric parameters (see the patents) which can be individually set to be positive, negative or null, an infinity of Quasiturbine configurations can be achieved. One of the most simple Quasiturbine geometry has no carriage (Model QT-SC) as follows:

This illustrates some details of a Quasiturbine without carriage (Model QT-SC).

Other more complex geometries involve carriages (Model QT-AC) as shown below.

QT-AC (With carriages) is intended for detonation mode,
where high surface-to-volume ratio
is a factor attenuating the violence of detonation.
Furthermore, the eccentricity is also an important geometric factor which dictates the shape of the stator as a more or less complex oval, to a very distorted shape still acceptable... The plurality of Quasiturbine designs produces different pressure and torque characteristics, often very different from the piston and the Wankel engine, which allows for operation mode not possible with the piston.
Each Quasiturbine device is at the crossroad of the 3 modern engines: Inspired by the turbine, it perfects the piston, and improves on the Wankel.
Quasiturbine SC - Without Carriage
The SC model has not internal parts - because the center is accessible, all engine components have a face accessible externally, including through the center. This property is quite precious in application related to thermal heat exchanges with the engine block.
When the eccentricity (here 0,578 for the model QT-SC, without carriage) is chosen such as to produce a straight side on the top and on the bottom, the Saint-Hilaire skating rink confinement profile is quite obvious:

Quasiturbine rotor confinement "Saint-Hilaire skating rink profile"
This configuration displaces its entire volume every revolution,
WHAT ABOUT A 3 LITERS DISPLACEMENT ENGINEINTO A 3 LITERS ENGINE VOLUME!Eccentricity can be still higher, but for current devices,
a less eccentric Quasiturbine is easier to built,
and well able to exceed piston engine performance.
Why does it Turn ?

This diagram show the force vector in a Quasiturbine when one or two opposed chambers are pressurized either by fuel combustion, or by external pressure fluids. Because the pressure vectors are off center, the Quasiturbine rotor experiences a net rotational force. It is that simple !

Click here for a 2000 pixels high resolution image
This diagram compares piston engine with steam and fuel combustion Quasiturbine.
Quasiturbine AC - With Carriages
More complex Quasiturbine designs can follow from the defining set of equations. Contrary to the piston or the Quasiturbine QT-SC (without carriage), which have volume characteristics near sinusoidal, the more complex Quasiturbine designs can shape the volume pulse almost at will by varying the parameter sets.

QT-AC (With carriages) is intended for detonation mode,
where high surface-to-volume ratio
is a factor attenuating the violence of detonation.

The parameters for the design below allow to shape the volume pressure pulse to have a tip 15 to 30 times shorter than the piston, which provide enhanced torque characteristics for pneumatic and steam Quasiturbine. But more important, this design is most suitable for detonation combustion engine mode, a superior mode the piston has failed to support for over 40 years !

                                        

Furthermore, in detonation mode, the high surface-to-volume ratio of this design
is an attenuation factor of the violence of the detonation.
Pneumatic - Steam
All of the Quasiturbine family designs can be used in pneumatic and steam mode.
Quasiturbine Uniflow Characteristic
In most reciprocating piston engines, the steam reverses its direction of flow at each stroke (counter-flow). By entering and exhausting the cylinder by the same port, the cylinder valve and walls are cooled by the passing exhaust steam, while the hotter incoming admission steam is wasting some of its energy in restoring the temperature. Some energy is further lost in reversing the motion momentum of the mass of steam within the piston. The aim of the piston uniflow is to remedy this defect by providing an exhaust port at the end of the stroke, making the steam flowing only in one direction, but has the inconvenience of recompressing some residual cylinder steam. Quasiturbine is a uniflow engine, with the further advantage of not recompressing any residual steam, resulting in superior energy efficiency.  Recompressing residual steam means some reversibility losses, and the pressure increases makes a substantial restriction to the initial steam flow into the chamber, not to ignore the truncated cycle near bottom dead center - None of this with the Quasiturbine.
Detonation Engine
Chemists know that the best way to burn fuel is with intense laser radiation. The photo-detonation (Auto Ignition) occurs at slightly higher pressure than the thermal ignition designated in the US as "Homogeneous-Charge Compression-Ignition" HCCI combustion, in Europe as "Controlled Auto Ignition" CAI combustion, and in Japan as "Active Thermo-Atmosphere" ATA combustion...
The efficiency at low load factor of the detonation engine is more than twice that of the conventional Beau de Rocha (Otto) cycle, and considering that the load factor of a car is in average about 10 to 15%, this is not a small difference... Even if the subject passionates the researchers, the thermic and photonic ignition control in the piston is still an unsolved problem, and possibly a dead-end ... that the Quasiturbine does overcome!

In combustion mode, the Quasiturbine QT-AC (With carriages)
is suitable for detonation mode,
where high surface-to-volume ratio is a factor attenuating the violence of detonation.
Source: http://quasiturbine.promci.qc.ca/ETheoryQTConcept.htm