... generation biogas SI engines knocking entropy exergy Nicolaus Otto built the first spark ignition (SI) engine in 1876, operating with the four-stroke cycles: Intake, compression, power, and exhaust [ 1 ]. SI engines are governed by the Otto cycle, where the ideal cycle assumes that all the heat...

...M. Mansour; N. Chokani; A. I. Kalfas; R. S. Abhari The time-dependent relative entropy field at the impeller exit of a centrifugal compressor is measured. This study is part of a broader effort to develop comprehensive measurement techniques that can be applied in the harsh environment...

.... Furthermore, combustion with the use of oxygen (in place of air) is also analyzed. The results showed that a system, which utilizes oxygen as an oxidizer, results in higher first and second law efficiencies as compared to the case with air as the oxidizer. The entropy generation for an adiabatic combustion...

...” irreversibility associated with film cooling is higher than the other irreversibilities at large fractional coolant flow. 05 07 2006 09 08 2006 11 01 2008 coolants cooling entropy flow gas turbines irreversible thermodynamics In an earlier paper ( 1 ), various ways for defining...

...Friedrich Bake; Nancy Kings; Ingo Roehle Entropy noise caused by combustors increases rapidly with rising Mach number in the nozzle downstream of the combustion chamber. This is experimentally shown with a dedicated test facility, in which entropy waves are generated in a controlled way by unsteady...

... and entropy ( p , s ) are required in the critical and supercritical regions (region 3 of IAPWS-IF97). With IAPWS-IF97, these calculations require cumbersome two-dimensional iteration of temperature T and specific volume v from ( p , h ) or ( p , s ) . While these calculations in region 3 are not frequently...

... deviation in flow channel sizes, caused by manufacturing tolerances in a rotary regenerative exchanger, is increased compared to the average flow channel diameter the effective number of transfer units decreases. Depending on the operating conditions, the entropy generation number either increases...

... in a wave and phase-change diagram. The thermodynamic process is shown in pressure–enthalpy and temperature–entropy diagrams. A computer program based on a thermodynamic model was generated to evaluate the performance of R718 baseline and wave-rotor-enhanced cycles. The effect of some key parameters...

... interpretation of approximate temperature-entropy diagrams and is qualitative only. In addition to identifying the cycles offering the greatest efficiency potential, the compromise between thermal efficiency and mean effective pressure is addressed. Contributed by the Internal Combustion Engine Division...

...H.-J. Kretzschmar; J. R. Cooper; A. Dittmann; D. G. Friend; J. S. Gallagher; K. Knobloch; R. Mareš; K. Miyagawa; I. Stöcker; J. Trübenbach; W. Wagner; Th. Willkommen In modeling steam power cycles, thermodynamic properties as functions of the variables enthalpy and entropy are required...

...J. Eckstein; E. Freitag; C. Hirsch; T. Sattelmayer “Rumble” is a self-excited combustion instability, usually occurring at the start-up of aero-engines with fuel-spray atomizers at sub-idle and idle conditions, and exhibiting low limit frequencies in the range of 50 Hz to 150 Hz . Entropy waves...

.... Nelson. 01 July 2000 01 Feb 2001 steam water thermodynamic properties enthalpy pressure specific heat entropy The advantage of the tabular Taylor series (TTSE) method is that it enables rapid calculation of thermodynamic properties without any necessary sacrifice...

... that, instead of using an expression for efficiency as one of the governing equations, performance can be accounted for directly, with entropy production. It is shown that: (1) the modeling is more straightforward, using fewer relations, and (2) that compressor performance (e.g., maps) can be represented...