Combined Energy and Exergy Analysis of a Nonisothermal Fin Array With Non-Boussinésq Variable Property Fluid

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Biplab Das ◽  
Asis Giri
Keyword(s):  
Nusselt Number ◽  
Entropy Production ◽  
Vertical Plate ◽  
Governing Equations ◽  
Energy And Exergy ◽  
Order Of Magnitude ◽  
Energy And Exergy Analysis ◽  
Conductance Parameter ◽  
Computational Fluid Dynamics Cfd ◽  
Fin Spacing

To transport the energy efficiently without much dissipation, first and second law analyses of mixed convection heat transport from an array of nonisothermal rectangular vertical plate-finned heat sink are made using purely computational fluid dynamics (CFD) analysis on the governing equations. Report provides the dependence of Nusselt number, entropy production, pumping power ratio (PPR), and flow bypass factor (BF) on the inlet velocity, fin conductance parameter, thermal Grashof number (Gr), dimensionless clearance (C*), and dimensionless fin spacing (S*). Total nondimensional entropy production is found to decrease continuously with clearances for all fin spacings, except at the lowest fin spacing involving lowest Gr (= 1.8 × 105). On the other hand, at higher inlet velocities, Nusselt number indicates an optimum value with clearances. Optimum Nusselt number is found to observe in a range of S* = 0.2–0.3 for all Gr. For smaller fin spacing, PPR is noticeably higher, but at the optimum value of fin spacing, PPR reduces roughly by an order of magnitude. Interestingly, flow bypass is remarkably lower at the optimum clearance. Finally, correlation of friction factor, PPR, and entropy generation is presented.

The Effects of Radiation on Free Convection Flow with Ramped Wall Temperature in Brinkman Type Fluid

2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Muhamad Najib Zakaria ◽  
Abid Hussanan ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Nusselt Number ◽  
Free Convection ◽  
Laplace Transform ◽  
Vertical Plate ◽  
Convection Flow ◽  
Physical Parameters ◽  
Governing Equations ◽  
Free Convection Flow ◽  
Laplace Transform Technique ◽  
Effects Of Radiation

The present paper is on study of the influence of radiation on unsteady free convection flow of Brinkman type fluid near a vertical plate containing a ramped temperature profile. Using the appropriate variables, the basic governing equations are reduced to nondimensional equations valid with the imposed initial and boundary conditions. The exact solutions are obtained by using Laplace transform technique. The influence of radiation near a ramped temperature plate is also compared with the flow near a plate with constant temperature. The numerical computations are carried out for various values of the physical parameters such as velocity, temperature, skin friction and Nusselt number and presented graphically.

A Review on Energy and Exergy Analysis of Two-Stage Vapour Compression Refrigeration System

2019 ◽  
Vol 27 (02) ◽  
pp. 1930001 ◽  
Author(s):  
Shounak Chowdhury ◽  
Ranendra Roy ◽  
Bijan Kumar Mandal
Keyword(s):  
Exergy Analysis ◽  
Refrigeration System ◽  
Alternative Refrigerants ◽  
Governing Equations ◽  
Two Stage ◽  
Numerical Investigations ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Exergetic Analysis ◽  
Vapour Compression

This paper presents a review on energy and exergy analysis of two-stage vapour compression refrigeration (VCR) system. The use of alternative refrigerants instead of conventional refrigerants has also been addressed. The governing equations for the energetic and exergetic analysis of two-stage VCR system have been identified and presented. Several experimental and numerical investigations and their findings on the performance of the two-stage VCR system available in the literature have been discussed in brief. Some of the results have also been reproduced as case studies.

scholarly journals An Exact Analysis of Heat and Mass Transfer Past a Vertical Plate with Newtonian Heating

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Abid Hussanan ◽  
Ilyas Khan ◽  
Sharidan Shafie
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Nusselt Number ◽  
Skin Friction ◽  
Heat And Mass Transfer ◽  
Vertical Plate ◽  
Newtonian Heating ◽  
Governing Equations ◽  
Exact Analysis ◽  
Temperature Distributions

An exact analysis of heat and mass transfer past an oscillating vertical plate with Newtonian heating is presented. Equations are modelled and solved for velocity, temperature, and concentration using Laplace transforms. The obtained solutions satisfy governing equations and conditions. Expressions of skin friction, Nusselt number, and Sherwood number are obtained and presented in tabular forms. The results show that increasing the Newtonian heating parameter leads to increase velocity and temperature distributions whereas skin friction decreases and rate of heat transfer increases.

Unsteady Hydromagnetic Natural Convection Flow of a Dusty Fluid Past an Impulsively Moving Vertical Plate With Ramped Temperature in the Presence of Thermal Radiation

2013 ◽  
Vol 80 (6) ◽  
Author(s):  
R. Nandkeolyar ◽  
G. S. Seth ◽  
O. D. Makinde ◽  
P. Sibanda ◽  
Md. S. Ansari
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Exact Solutions ◽  
Skin Friction ◽  
Vertical Plate ◽  
Governing Equations ◽  
Dusty Fluid ◽  
Flow Parameters ◽  
Particle Velocities

Unsteady hydromagnetic natural convection boundary layer flow of a viscous, incompressible, and electrically conducting dusty fluid past an impulsively moving vertical plate with ramped temperature in the presence of thermal radiation and transverse magnetic field is studied. Exact solutions of the governing equations for fluid and particle velocities and fluid and particle temperatures are obtained in closed form by Laplace transform technique. To compare the results obtained in this case with that of an isothermal plate, exact solutions of the governing equations are also obtained for an isothermal plate. The expressions for the skin friction and Nusselt number are also derived for both ramped temperature and isothermal plates. Numerical values of fluid and particle velocities and fluid and particle temperatures are displayed graphically for various values of pertinent flow parameters for both ramped temperature and isothermal plates, whereas numerical values of skin friction and Nusselt number for both ramped temperature and isothermal plates are presented in tabular form for pertinent flow parameters.

scholarly journals Performance analysis of a novel integrated photovoltaic–thermal system by top-surface forced circulation of water

Clean Energy ◽  
2020 ◽  
Author(s):  
Md Arman Arefin ◽  
Mohammad Towhidul Islam ◽  
Mohammad Zunaed ◽  
Khodadad Mostakim
Keyword(s):  
No Value ◽  
Forced Circulation ◽  
Pv Panel ◽  
Photovoltaic Thermal System ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Mass Flow Rates ◽  
Overall Efficiency ◽  
The Individual ◽  
Over The Top

Abstract Almost 80–90% of energy is wasted as heat (provides no value) in a photovoltaic (PV) panel. An integrated photovoltaic–thermal (PVT) system can utilize this energy and produce electricity simultaneously. In this research, through energy and exergy analysis, a novel design and methodology of a PVT system are studied and validated. Unlike the common methods, here the collector is located outside the PV panel and connected with pipes. Water passes over the top of the panel and then is forced to the collector by a pump. The effects of different water-mass flow rates on the PV panel and collector, individual and overall efficiency, mass loss, exergetic efficiency are examined experimentally. Results show that the overall efficiency of the system is around five times higher than the individual PV-panel efficiency. The forced circulation of water dropped the panel temperature and increased the panel efficiency by 0.8–1% and exergy by 0.6–1%, where the overall energy efficiency was ~81%.

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