نتایج جستجو برای: entropy generation

تعداد نتایج: 418190  

2014
SOMPOP JARUNGTHAMMACHOTE

Analysis of entropy generation rate for transient heat conduction, taking place in homogeneous solid slab with fixed temperature boundary conditions, is presented. The initial condition is defined as a constant temperature. The exact solution is solved and used to analyze the local and total entropy generation rates. Two cases, heating and cooling processes, are considered in this study. It is ...

2003
O. M. Haddad M. K. Alkam M. T. Khasawneh

This study is focused on the entropy production due to laminar forced convection in the entrance region of a concentric cylindrical annulus. The present hydrodynamic and temperature fields are obtained numerically. Local entropy generation distributions are obtained based on the resulting velocity and temperature fields by solving the entropy generation equation. The effect of different flow pa...

Journal: :Entropy 2014
Hooman Yarmand Goodarz Ahmadi Samira Gharehkhani Salim N. Kazi Mohammad R. Safaei Maryam Sadat Alehashem Abu Bakar Mahat

The entropy generation based on the second law of thermodynamics is investigated for turbulent forced convection flow of ZrO2-water nanofluid through a square pipe with constant wall heat flux. Effects of different particle concentrations, inlet conditions and particle sizes on entropy generation of ZrO2-water nanofluid are studied. Contributions from frictional and thermal entropy generations ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم پایه 1391

bekenstein and hawking by introducing temperature and every black hole has entropy and using the first law of thermodynamic for black holes showed that this entropy changes with the event horizon surface. bekenstein and hawking entropy equation is valid for the black holes obeying einstein general relativity theory. however, from one side einstein relativity in some cases fails to explain expe...

Journal: :Entropy 2017
Yikun Wei Zhengdao Wang Yuehong Qian

Entropy generation in two-dimensional Rayleigh-Bénard convection at different Prandtl number (Pr) are investigated in the present paper by using the lattice Boltzmann Method. The major concern of the present paper is to explore the effects of Pr on the detailed information of local distributions of entropy generation in virtue of frictional and heat transfer irreversibility and the overall entr...

This paper presents a gas turbine cycle combined with a solid oxide fuel cell with hydrogen fuels is thermodynamically modeled. In this way all components of the system are separately modeled. Fuel cell model presented, as well as show its behavior in different condition performance. Then, the effects of various parameters on efficiency, power and entropy generation was evaluated and for acc...

Journal: :transport phenomena in nano and micro scales 2015
a. aghaei g.a. sheikhzadeh h.r. ehteram m. hajiahmadi

natural convection heat transfer has many applications in different fields of industry; such as cooling industries, electronic transformer devices and ventilation equipment; due to simple process, economic advantage, low noise and renewed retrieval. recently, heat transfer of nanofluids have been considered because of higher thermal conductivity coefficient compared with those of ordinary fluid...

2002
Dmitriy Genzel Eugene Charniak

We present a constancy rate principle governing language generation. We show that this principle implies that local measures of entropy (ignoring context) should increase with the sentence number. We demonstrate that this is indeed the case by measuring entropy in three different ways. We also show that this effect has both lexical (which words are used) and non-lexical (how the words are used)...

In the current work optimization of double pipe fin-pin heat exchanger has been studied. The effective parameters those are controlling the heat exchanger performance are divided in two categories; geometrical and operating conditions. Using the Brent’s optimization algorithm and handling the thermodynamically design concept, one can minimize entropy generation in different length of heat excha...

Journal: :Entropy 2016
Mohammad Nasiri Mohammad Mehdi Rashidi Giulio Lorenzini

In this study, convection flow in microchannel heat sink with offset fan-shaped reentrant cavities in sidewall filled with Fe3O4-water is numerically investigated. The effects of changing some parameters such as Reynolds number and magnetic field are considered. The nanofluid flow is laminar, steady and incompressible, while the thermo-physical properties of nanoparticles were assumed constant....

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید