Experimental and Computational Fluid Dynamics Study on Fluid Flow and Heat Transfer in Triangular Passage Solar Air Heater of Different Configurations

2017 ◽  
Vol 139 (4) ◽  
pp. 041013 ◽  
Author(s):  
Rajneesh Kumar ◽  
Varun ◽  
Anoop Kumar
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Solar Air Heater ◽  
Air Heater ◽  
Flow And Heat Transfer

Performance Investigation of a Triangular Solar Air Heater Duct Having Broken Inclined Roughness Using Computational Fluid Dynamics

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Sheetal Kumar Jain ◽  
Ghanshyam Das Agrawal ◽  
Rohit Misra ◽  
Prateek Verma ◽  
Sanjay Rathore ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Scale ◽  
Rectangular Cross Section ◽  
Heated Surface ◽  
Clean Energy ◽  
Solar Air Heater ◽  
Air Heater ◽  
Gap Width

Large-scale adaptation of solar air heating in industries and agro-processing will lead to clean energy processing as well as reducing the production cost for these industries. The solar air heater uses the principle of the greenhouse effect to heat air through the collected heat in the absorber. Among the various techniques employed by the researchers to augment heat transfer, the addition of artificial roughness elements/fins/corrugations on the heated surface is the promising one for heat transfer augmentation. In the present work, the effect of broken inclined ribs with rectangular cross-section on heat transfer and friction characteristics of the equilateral triangular passage duct has been analyzed using computational fluid dynamics. The effect of roughness parameters, viz., relative gap position and relative gap width, is being investigated for the Reynolds number (Re) ranging from 4000 to 18,000. The values of relative gap position (d/W) and relative gap width (g/e) are varied from 0.16 to 0.67 and 0.5 to 2, respectively, while a constant heat flux is supplied on the absorber side, other surfaces being insulated. The Nusselt number increased up to 2.16 times by using broken ribs than that of the smooth duct at d/W = 0.25 and g/e = 1.

A CFD (Computational Fluid Dynamics) Based Thermal Performance of Solar Air Heater With Rib-Roughened Channels

2016 ◽  
Author(s):  
Mumtaz Hussain Qureshi ◽  
M. Shakaib
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Flux ◽  
Computational Fluid Dynamics ◽  
Research Work ◽  
Solar Air Heater ◽  
Transfer Coefficients ◽  
Turbulent Fluid Flow ◽  
Transfer Rates ◽  
Air Heater

Computational Fluid Dynamics (CFD) study is conducted to determine turbulent fluid flow and temperature profiles in rectangular ribbed channels of solar air heater. The results show significant effect of Reynolds number and ribs height and pitch on turbulence and heat transfer rates. When heat flux is defined at the bottom wall, the temperature values increase rapidly near the ribs due to stagnant zones. The heat transfer coefficients are lower at these locations. When heat flux is specified at the top wall, the variation in heat transfer coefficient is relatively smooth. From the research work, the channel containing ribs of 3mm and pitch 40mm are determined suitable due to higher heat transfer rates.

Detailed Study of Fluid Flow and Heat Transfer in the Abrasive Grinding Contact Using Computational Fluid Dynamics Methods

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Stefan D. Mihić ◽  
Sorin Cioc ◽  
Ioan D. Marinescu ◽  
Michael C. Weismiller
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
3D Models ◽  
Liquid Volume ◽  
Fluid Composition ◽  
Grinding Process ◽  
Flow And Heat Transfer ◽  
Simulation Results

This paper introduces a set of research oriented computational fluid dynamics (CFD) 3D models used to simulate the fluid flow and heat transfer in a grinding process. The most important features of these models are described and some representative simulation results are presented, along with comparisons to published experimental data. Distributions of temperatures, pressures, velocities, and liquid volume fractions in and around the grinding region are obtained in great detail. Such results are essential in studying the influence of the fluid on the grinding process, as well as in determining the best fluid composition and supply parameters for a given application. The simulation results agree well with experimental global flow rates, temperature, and pressure values, showing the feasibility of CFD simulations in grinding applications.

Modeling of the Fluid Flow and Heat Transfer an a Pebble Bed Modular Reactor Core With a Computational Fluid Dynamics Code

2002 ◽  
Author(s):  
J. Bryce Taylor ◽  
Savas Yavuzkurt ◽  
Anthony J. Baratta
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Future Research ◽  
Empirical Correlations ◽  
Flow And Heat Transfer

The Pebble Bed Modular Reactor (PBMR), a promising Generation IV nuclear reactor design, raises many novel technological issues for which new experience and techniques must be developed. This brief study explores a few of these issues, utilizes a computational fluid dynamics code to model some simple phenomena, and points out deficiencies in current knowledge that should be addressed by future research and experimentation. A highly simplified representation of the PBMR core is analyzed with FLUENT, a commercial computational fluid dynamics code. The applied models examine laminar and turbulent flow in the vicinity of a single spherical fuel pebble near the center of the core, accounting for the effects of the immediately adjacent fuel pebbles. Several important fluid flow and heat transfer parameters are examined, including heat transfer coefficient, Nusselt number, and pressure drop, as well as the temperature, pressure, and velocity profiles near the fuel pebble. The results of these “unit cell” calculations are also compared to empirical correlations available in the literature. As FLUENT is especially sensitive to geometry during the generation of a computational mesh, the sensitivity of code results to pebble spacing is also examined. The results of this study show that while a PBMR presents a novel and complex geometry, a code such as FLUENT is suitable for calculation of both local and global flow characteristics, and can be a valuable tool for the thermal-hydraulic study of this new reactor design. FLUENT results for pressure drop deviate from the Darcy correlation by several orders of magnitude in all cases. When determining the heat transfer coefficient, FLUENT is again much lower than Robinson’s correlation. Results for Nusselt number show better agreement, with FLUENT predicting results that are 10 or 20 times as large as those from the Robinson and Lancashire correlations. These differences may arise because the empirical correlations concern mainly integral parameters, while the FLUENT model focuses on local flow behaviors. Local phenomena are significant in the case of local heat transfer characteristics, fine temperature distribution calculations to identify hot spots, and fission product transport phenomena. All of these are important to a safety analysis of the PBMR reactor during normal operation, as well as during transient circumstances, and should be the focus of future research efforts.

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