...Tapasvi Bhatt; Jainil Shah; Naman Jain; Suvanjan Bhattacharyya The present study primarily investigates the exergy and entropy generation in a heat exchanger influenced by the combined effects of mechanical vibrations and magnetic fields. A rectangular channel with dimensions 40 mm in length and 4...

..., pressure, and temperature. The present study aims to analyze entropy generation for convection in nanofluids. After solving u , v , and Θ , different entropy parameters can be written in nondimensional form based on the local thermodynamic equilibrium of linear transport theory [ 20 , 45...

...? entransy entropy exergy The science of thermodynamics as part of the physics nowadays is well established, based on four principle laws (numbered 0–3), and widely accepted as one of the fundamental sciences. Historically, there was some confusion with respect to “heat” as a thermodynamic...

... responsible for the difference in performance of Al 2 O 3 –water and Cu–water nanofluid as far as entropy generation is concerned. 1 Corresponding author. Contributed by the Heat Transfer Division of ASME for publication in the J OURNAL OF H EAT T RANSFER . Manuscript received October 13, 2011...

...Nobuhide Kasagi; Yosuke Hasegawa; Koji Fukagata; Kaoru Iwamoto Because of the importance of fundamental knowledge on turbulent heat transfer for further decreasing entropy production and improving efficiency in various thermofluid systems, we revisit a classical issue whether enhancing heat...

...Heinz Herwig Entropy generation in a velocity and temperature field is shown to be very significant in momentum and heat transfer problems. After the determination of this postprocessing quantity, many details about the physics of a problem are available. This second law analysis (SLA) is a tool...

... an implicit finite difference method under the similarity assumption and these results are used to compute the entropy generation rate N s , irreversibility ratio Φ , and the Bejan number Be for both Newtonian and non-Newtonian fluids. The effects of viscous frictional parameter G , Rayleigh number Ra...

.... The effects of inlet conditions of the working fluids on the heat transfer characteristics were correlated via entropy generation number and exergy loss. The variation of the effectiveness with the number of transfer unit of heat recovery unit was calculated and discussed in terms of literature. 08 03...

...Pouria Ahmadi; Hassan Hajabdollahi; Ibrahim Dincer In the present work, a thermal modeling is conducted for optimal design of compact heat exchangers in order to minimize cost and entropy generation. In this regard, an ε − NTU method is applied for estimation of the heat exchanger pressure drop...

...Jie Li; Clement Kleinstreuer Employing a validated computer simulation model, entropy generation is analyzed in trapezoidal microchannels for steady laminar flow of pure water and CuO-water nanofluids. Focusing on microchannel heat sink applications, local and volumetric entropy rates caused...

...Meghdad Saffaripour; Richard Culham A new nonintrusive and whole field method for the measurement of entropy generation in microscale thermal-fluid devices is presented. The rate of entropy generation is a measure of the thermodynamic losses or irreversibilities associated with viscous effects...

...Ahmad Fakheri This paper further explores the topic of an ideal heat exchanger, which is still an open question. It is shown that the minimization of entropy production or exergy destruction should not be an objective in heat exchanger design. It is further proven that heat exchanger effectiveness...

...A. Arikoglu; G. Komurgoz; I. Ozkol; A. Y. Gunes The present work examines the effects of temperature and velocity jump conditions on heat transfer, fluid flow, and entropy generation. As the physical model, the axially symmetrical steady flow of a Newtonian ambient fluid over a single rotating disk...

... of entropy are processes inherently associated with thermal energy transport, yet little has been done to analyze entropy generation in solids at length scales comparable with or smaller than the mean free path of heat carriers. This work extends the concept of radiation entropy in a participating medium...

... of energy are evaluated by the entropy generation number and exergy losses, the CH-STHX decreased the entropy generation number and exergy losses by 30% and 68% on average than the SG-STHX for the same Reynolds number. The analysis from nondimensional correlations for Nusselt number and friction factor also...

...Mohammad Shanbghazani; Vahid Heidarpoor; Marc A. Rosen; Iraj Mirzaee The entropy generation is investigated numerically in axisymmetric, steady-state, and incompressible laminar flow in a rotating single free disk. The finite-volume method is used for solving the momentum and energy equations...

... . Two performance measures are used to compare the different pin fin densities. The first measure is to maximize heat transfer capacity for a given pumping power compared with a plane channel. The second measure used is based on entropy generation minimization (EGM), where the objective is to reduce...

... medium system is considered. Key results from the application of this theory are used to develop a simplified entropy inequality, which is in turn used to guide the development of closure relations. The decomposition of exchange terms is considered, and closed models for internal energy are derived...

... geometry exergetically achieves the highest efficiencies. The difference between the two results is mainly through the accounting of entropy generation and exergy destroyed, and the largest mode of thermal exergy loss is found to be through entropy generation resulting from heat transfer accompanying phase...

... and porosity. The thermal performance was evaluated by the ratio of the Nusselt number with and without a high porous material and the entropy generation. It was recognized that the high porous material was effective in low Reynolds numbers and the Reynolds number, which minimized the entropy generation...