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Entropy generation analysis of heat and mass transfer in mixed electrokinetically and pressure driven flow through a slit microchannel

Matin, Meisam Habibi; Khan, Waqar Ahmed - In: Energy 56 (2013) C, pp. 207-217

The entropy generation analysis of heat and mass transfer in a slit microchannel is performed in this study. The flow is assumed to be due to a combination of the electroosmotic body force and the pressure gradient. A fully developed flow with uniform flux at the surface is considered in the...

Persistent link: https://www.econbiz.de/10010810009

Radiation energy devaluation in diffusion combusting flows of natural gas

Makhanlall, Deodat; Munda, Josiah L.; Jiang, Peixue - In: Energy 61 (2013) C, pp. 657-663

CFD (Computational fluid dynamics) is used to evaluate the thermodynamic second-law effects of thermal radiation in turbulent diffusion natural gas flames. Radiative heat transfer processes in gas and at solid walls are identified as important causes of energy devaluation in the combusting...

Persistent link: https://www.econbiz.de/10010810972

Optimization principles for convective heat transfer

Chen, Qun; Wang, Moran; Pan, Ning; Guo, Zeng-Yuan - In: Energy 34 (2009) 9, pp. 1199-1206

Optimization for convective heat transfer plays a significant role in energy saving and high-efficiency utilizing. We … compared two optimization principles for convective heat transfer, the minimum entropy generation principle and the entransy … dissipation extremum principle, and analyzed their physical implications and applicability. We derived the optimization equation …

Persistent link: https://www.econbiz.de/10010811085

Performance of solar air heater ducts with different types of ribs on the absorber plate

Tanda, Giovanni - In: Energy 36 (2011) 11, pp. 6651-6660

Repeated ribs are considered an effective technique to enhance forced convection heat transfer in channels. In order to establish the performance of rib-roughened channels, both heat transfer and friction characteristics have to be accounted for. In the present paper, heat transfer coefficients...

Persistent link: https://www.econbiz.de/10010811247

Viscous dissipation effect on entropy generation in curved square microchannels

Guo, Jiangfeng; Xu, Mingtian; Cai, Jun; Huai, Xiulan - In: Energy 36 (2011) 8, pp. 5416-5423

The viscous dissipation effect on the thermodynamic performance of the curved square microchannels in laminar flow is numerically investigated. The classical Navier–Stokes equations are adopted; aniline and ethylene glycol are selected as the working fluids. The results show that the heat...

Persistent link: https://www.econbiz.de/10010811378

Optimization principles for two-stream heat exchangers and two-stream heat exchanger networks

Cheng, Xuetao; Liang, Xingang - In: Energy 46 (2012) 1, pp. 386-392

This paper presents the relationships for the heat transfer performance of two-stream heat exchangers (THEs) and two-stream heat exchanger networks (THENs) with the entropy generation, the entropy generation number, the revised entropy generation number, the entransy dissipation, the entransy...

Persistent link: https://www.econbiz.de/10010811519

Parametric analysis and optimization of entropy generation in unsteady MHD flow over a stretching rotating disk using artificial neural network and particle swarm optimization algo...

Rashidi, M.M.; Ali, M.; Freidoonimehr, N.; Nazari, F. - In: Energy 55 (2013) C, pp. 497-510

applies Artificial Neural Network (ANN) and Particle Swarm Optimization (PSO) algorithm in order to minimize the entropy …

Persistent link: https://www.econbiz.de/10010811658

Entropy resistance minimization: An alternative method for heat exchanger analyses

Cheng, XueTao - In: Energy 58 (2013) C, pp. 672-678

In this paper, the concept of entropy resistance is proposed based on the entropy generation analyses of heat transfer processes. It is shown that smaller entropy resistance leads to larger heat transfer rate with fixed thermodynamic force difference and smaller thermodynamic force difference...

Persistent link: https://www.econbiz.de/10010811963

Overview on fuel cells

Lucia, Umberto - In: Renewable and Sustainable Energy Reviews 30 (2014) C, pp. 164-169

Progress always requires energy. Up today, the energy needs have been provided by combustion of fossil fuels and this has increased the air pollution and the emission of greenhouse gasses. Consequently, the greenhouse emission problem could represents a concrete opportunity to promote the...

Persistent link: https://www.econbiz.de/10010729929

Entropy generation: Minimum inside and maximum outside

Lucia, Umberto - In: Physica A: Statistical Mechanics and its Applications 396 (2014) C, pp. 61-65

The extremum of entropy generation is evaluated for both maximum and minimum cases using a thermodynamic approach which is usually applied in engineering to design energy transduction systems. A new result in the thermodynamic analysis of the entropy generation extremum theorem is proved by the...

Persistent link: https://www.econbiz.de/10010730356