Lenoir cycle

Abstract: An analytical investigation was conducted of the idealized performance potential, from a thermodynamic cycle viewpoint, of airbreathing pulse-detonation engines (PDEs) primarily intended for air-vehicle propulsion The investigation was restricted to the static operation of PDEs The detonation-wave model used was of the classical Zel’dovich‐von Neumann‐Doering type, in which an initiating shock wave is followed by a Rayleigh-type combustion process in a duct, the detonation tube, of uniform cross-sectional area The results of the analysis indicated that the idealized PDEperformance wasonly slightly betterthan thatofa simple,easily analyzed,constant-volume combustion, Lenoir-type surrogate cycle The PDE also had the potential of being slightly more efe cient, under idealized e ight conditions, with induction ramming occurring, than the corresponding surrogate cycle The corresponding surrogate cycle will advance thermodynamically, due to intake ramming, from a relatively inefe cient Lenoir cycle to a more efe cient Humphrey, or Atkinson, cycle

Abstract: The multifuel combustion engine is a Lenoir cycle (constant volume), pulst combustion engine capable of operating on gasoline, diesel or kerosene based fuels. Although the preferred embodiment is described in terms of Lenoir cycle pulsejet engines, the present invention has application to combustion engines in general. The conventional Lenoir cycle engine has been modified to provide a direct, premixed fuel-air spray to the combustion chamber and means for igniting the fuel-air spray. Said fuel-air spray is separate and distinct from the fuel-air charge which is fed to the combustion chamber from the engine head. Additionally, means are provided for preheating the combustion chamber so that the same fuel-air ratio mixes can be fed to the combustion chamber for cold start or hot restart of the engine. A method of burning different fuels in combustion engines is also claimed. The present invention includes the application of the modified Lenoir cycle engines to smoke generator equipment.

Abstract: In the existing thermal engine concepts negative work transfer (usually needed to drive a compression process) is supplied by the work produced by the engine itself. The remaining difference (i.e., the net work transfer) becomes the useful work, since it is available for external consumption. The thermal efficiency is the parameter that compares this against the heat input into the system. It forms the main optimization parameter in any engine design. The objective of the present study is to show that for the case of the Lenoir cycle with regenerative preheating the entire positive work is available for external consumption, since the negative (i.e., the compression) work is supplied by the atmospheric air. Not only this, but, during the compression process and due to the pressure difference across the two sides of the moving piston, an additional (useful) work transfer may be generated. Thus, the proposed power plant may be considered as a combination of a thermal engine and a wind turbine. In the ideal cycle limit (at least), the total amount of useful work exceeds the heat entering the system. This leads to the definition of a new parameter for the efficiency (called the technical efficiency), which compares the combined positive work transfer (i.e., the useful one) against the heat entering the system and which may exceed the 100% level.

Abstract: This paper presents description and thermodynamic analysis of a new thermodynamic cycle. Realization of this new cycle is possible to achieve with valveless internal combustion engine with more complete expansion. The main purpose of this new IC engine is to increase engines’ thermal efficiency. The engine was designed so that the thermodynamic changes of the working fluid are different than in conventional engines. Specific differences are reflected in a more complete expansion of the working fluid (the expansion stroke is larger than compression stroke), valveless gas flowing and complete discharge of residual combustion products from the combustion chamber. In this concept, the movement of the piston is different than in conventional piston mechanisms. The results obtained herein include the efficiency characteristics of irreversible reciprocating new engine cycle which is very similar to Miller cycle. The results show that with this thermodynamic cycle engine has higher efficiency than with the standard Otto cycle. In this article, the patent application material under number 2008/607 at the Intellectual Property Office of the Republic of Serbia was used.