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High-efficiency Hybrid Cycle
The high-efficiency hybrid cycle (HEHC) is a new 4-stroke thermodynamic cycle combining elements of the Otto cycle, Diesel cycle, Atkinson cycle and Rankine cycle. HEHC engines The 3rd generation design of the Liquidpiston The red line is a three lobe epitrochoid, which is the shape of the LiquidPiston's swept volume The X-engine is a type of pistonless rotary engine manufactured by LiquidPiston of Bloomfield, Connecticut. The X engine is a hybrid cycle rotar ... Engine currently in development is the only engine currently designed around the HEHC. It is a rotary combustion engine. References External links LiquidPiston Inc.– The company designing the first HEHC-based engine MIT News article: "Small engine packs a punch" (December 5, 2014) Thermodynamic cycles {{Thermodynamic cycles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-stroke
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed: #Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing a partial vacuum (negative pressure) in the cylinder through its downward motion. #Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are closed during this stage. #Combustion: Also known as power or ignition. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermodynamic Cycle
A thermodynamic cycle consists of linked sequences of thermodynamic processes that involve heat transfer, transfer of heat and work (physics), work into and out of the system, while varying pressure, temperature, and other state variables within the system, and that eventually returns the thermodynamic system, system to its initial state. In the process of passing through a cycle, the working fluid (system) may convert heat from a warm source into useful work, and dispose of the remaining heat to a cold sink, thereby acting as a heat engine. Conversely, the cycle may be reversed and use work to move heat from a cold source and transfer it to a warm sink thereby acting as a heat pump. If at every point in the cycle the system is in thermodynamic equilibrium, the cycle is reversible. Whether carried out reversible or irreversibly, the net entropy change of the system is zero, as entropy is a state function. During a closed cycle, the system returns to its original thermodynamic stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Cycle
An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines. The Otto cycle is a description of what happens to a gas as it is subjected to changes of pressure, temperature, volume, addition of heat, and removal of heat. The gas that is subjected to those changes is called the system. The system, in this case, is defined to be the fluid (gas) within the cylinder. Conversely, by describing the changes that take place within the system it also describes the system's effect on the environment. The purpose of the Otto cycle is to study the production of net work from the system that can propel a vehicle and its occupants in the environment. The Otto cycle is constructed from: :Top and bottom of the loop: a pair of quasi-parallel and isentropic processes (frictionless, adiabatic reversible). :Left and right sides of the loop: a pair of parallel i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Cycle
The Diesel cycle is a combustion process of a reciprocating internal combustion engine. In it, fuel is ignited by heat generated during the compression of air in the combustion chamber, into which fuel is then injected. This is in contrast to igniting the fuel-air mixture with a spark plug as in the Otto cycle (four-stroke/petrol) engine. Diesel engines are used in aircraft, automobiles, power generation, diesel–electric locomotives, and both surface ships and submarines. The Diesel cycle is assumed to have constant pressure during the initial part of the combustion phase (V_2 to V_3 in the diagram, below). This is an idealized mathematical model: real physical diesels do have an increase in pressure during this period, but it is less pronounced than in the Otto cycle. In contrast, the idealized Otto cycle of a gasoline engine approximates a constant volume process during that phase. Idealized Diesel cycle The image shows a p–V diagram for the ideal Diesel cycle; wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atkinson Cycle
The Atkinson-cycle engine is a type of internal combustion engine invented by James Atkinson (inventor), James Atkinson in 1882. The Atkinson cycle is designed to provide Energy conversion efficiency, efficiency at the expense of power density. A variation of this approach is used in some modern automobile engines. While originally seen exclusively in hybrid electric applications such as the earlier-generation Toyota Prius, later hybrids and some non-hybrid vehicles now feature engines with variable valve timing, which can run in the Atkinson cycle as a part-time operating regimen, giving good economy while running in Atkinson cycle, and conventional power density when running as a conventional, Otto cycle engine. Design Atkinson produced three different designs that had a short compression stroke and a longer expansion stroke. The first Atkinson-cycle engine, the ''differential engine'', used opposed pistons. The second and best-known design was the ''cycle engine'', which used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rankine Cycle
The Rankine cycle is an idealized thermodynamic cycle describing the process by which certain heat engines, such as steam turbines or reciprocating steam engines, allow mechanical work to be extracted from a fluid as it moves between a heat source and heat sink. The Rankine cycle is named after William John Macquorn Rankine, a Scottish polymath professor at Glasgow University. Heat energy is supplied to the system via a boiler where the working fluid (typically water) is converted to a high-pressure gaseous state (steam) in order to turn a turbine. After passing over the turbine the fluid is allowed to condense back into a liquid state as waste heat energy is rejected before being returned to boiler, completing the cycle. Friction losses throughout the system are often neglected for the purpose of simplifying calculations as such losses are usually much less significant than thermodynamic losses, especially in larger systems. Description The Rankine cycle closely describes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquidpiston
The red line is a three lobe epitrochoid, which is the shape of the LiquidPiston's swept volume The X-engine is a type of pistonless rotary engine manufactured by LiquidPiston of Bloomfield, Connecticut. The X engine is a hybrid cycle rotary engine. Design This is geometrically an inverted Wankel engine that operates on the high-efficiency hybrid cycle. In the Wankel, the only successful pistonless rotary engine to date, a figure-eight-like epitrochoid housing surrounds a curved sided triangular rotor. The rotor revolves around a fixed gear in a hula-hoop motion. The output shaft revolves at three times the speed of the rotor. One power pulse is delivered in one revolution of the output shaft. For comparison a single cylinder four-stroke piston engine delivers one power pulse for two rotations of the output shaft. The three operating chambers of the Wankel formed by the triangular rotor are separated by seals installed on the three apexes of the rotor. They require e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotary Combustion Engine
A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does. Designs vary widely but typically involve one or more rotors, sometimes called rotary pistons, as described in QT-Wankel: Two Concepts 100 Years Apart. Although many different designs have been constructed, only the Wankel engine has achieved widespread adoption. The term rotary combustion engine has been used as a name for these engines to distinguish them from early (generally up to the early 1920s) aircraft engines and motorcycle engines also known as ''rotary engines''. However, both continue to be called ''rotary engines'' and only the context determines which type is meant, whereas the "pistonless" prefix is less ambiguous. Pistonless rotary engines A pistonless rotary engine replaces the linear reciprocating motion of a piston with more complex compression/expansion motions with the objective of improving some aspect of the engine's operation, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
