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EPITROTURBINE ENGINE (Epitrochoid turbine engine). Concept of a new engine. The engine consists out of two moving parts. It can run on almost everything that can burn, provided that the burner is right for that fuel, and the waste gases don't hamper the function of the turbine. The concept: Air is compressed by a compression turbine, fuel is burned with that air, and an expansion turbine uses the energy of the expansion to power the compression turbine, just like a conventional gas turbine engine (the Brayton cycle). But for both turbines an epitrochoid progressive cavity turbine is used. (for more about the epitrochoid turbine click here). 
What is the advantage of using two epitrochoid progressive cavity turbines? These turbines have the special quality that they compress and expand gas at the same rate, independent of the speed of rotation (just like a conventional cylinder with piston engine). A conventional gas turbine engine is still not offen used in stead of the piston engines in cars because they do not work efficiently on a wide range of speeds, although they work very efficient on the specific speed they are designed for. This engine combines the advantage of both the piston and the turbine engine, high efficiency on a wide range of speeds. Although there are a lot of ways to construct an engine with this concept, I want to present here a design that uses the special characteristics of two epitrochoid turbines.  Click here for the animation of a rotation of the epitrochoid rotor. As the compressor I want to use a epitrochoid helix cone rotor and an eight-shaped helix cone housing, or an epitrochoid helix cone housing with a helix cone rotor that has the form that u can see here.The rotor is twisted to form a spiral, and the rotor housing also (like in a Moineau pump). As expansion turbine I want to use the same shape. ROTOR IN EPITROCHOID HOUSING 
Click here for the animation of a rotor in an epitrochoid house.
Those rotors can be made in one piece as one rotor. When the crank goes from one end to the other trough the rotating axis of the crankshaft, then both motions fit together. So the engine exist out of only two moving parts: the rotor and the crankshaft. At the spot between the compression and the compression part of the rotor I want to make a sealing in the shape of a hollow ball through which the crank leads from one end to the other. 
Click here for the animation of a rotor in an epitrochoid house.
There can be a gap between the rotor ball part and the rotor housing, in which case the air flowing through this small gap is used to cool the rotor and the combustion chamber wall (the expansion because of the pressure drop caused by the shortcut cools the air that flows through the gap). It is also possible to seal the gap with an annular ring or spring, but it seems to me better not to seal here because of the problems of friction at high temperature. Cooling: Cooling air can flow through the rotor, forced by fixed turbine blades inside the rotor. Advantages of an epitrochoid turbine engine: 1. It uses the highly efficient Brayton cycle Gases passing through an ideal gas turbine undergo three thermodynamic processes. These are isentropic compression, isobaric (constant pressure) combustion and isentropic expansion. Together, these make up the Brayton cycle. 2. High power density (i.e. the ratio of power to weight, or power to volume). This is because of their ability to operate at very high speeds with a continuous process. 3. Less vibration than a reciprocating engine. This is because the two moving parts can both be fully balanced, and the combustion is a continuous process. 4. Only two moving parts. 5. Ball bearings or needle bearings can be used on spots with a low temperature to let the two moving parts move with very low friction. 6. Can run on a wide variety of fuels. 7. Very low toxic emissions of CO and HC due to excess air, complete combustion and no "quench" of the flame on cold surfaces. |
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The four images in the row below is the cross section at every time 90 degrees rotation of the crankshaft. The crankshaft is represented by the red dot you see on the white circle. Imagine the top row as the cross section of the rotor and the rotor housing on the other end. The crank goes through the middle of the diabolo shaped rotor to the opposite side. Note that the red dot, representing the crank is on the other side of the circle when you compare two images in a column. Now in the row below you see the rotor rotated around the crank 45 degrees to the right with every 90 degrees rotation of the crankshaft. In the top row the same happens. This is the evidence that the rotor will rotate in the way it should. Why is this important? It means that the compressor turbine and the expansion turbine can be made in one piece. The gear mechanisme to drive the rotor in the rotor housing does not have to be repeated on the other side. The force to drive the compressor goes from the expansion turbine straight through the rotor to the compressor turbine, bypassing gear and bearings. The engine only needs two moving parts. For two mechanisms to drive the rotor along the right path through the epitrochoid shaped housing, click here. Author: Harrie van der Haghen For questions or remarks, email to: hvd@haghen.nl |
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