scholarly journals Validation Study of Photovoltaic Thermal Nanofluid Based Coolant Using Computational Fluid Dynamics Approach

CFD letters ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 58-71
Author(s):  
Mohd Afzanizam Mohd Rosli ◽  
Yew Wai Loon ◽  
Muhammad Zaid Nawam ◽  
Suhaimi Misha ◽  
Aiman Roslizar ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Surface Temperature ◽  
Validation Study ◽  
Numerical Approach ◽  
Experimental Results ◽  
Thermal System ◽  
Outlet Temperature ◽  
Photovoltaic Thermal System ◽  
Simulation Results

In the study, the photovoltaic thermal system using nanofluid as coolant is validated using numerical approach by comparing the experimental results and simulation results. Due to high cost and difficulty in preparing nanofluid, it is more practical to perform the study using numerical approach which is convenient and saves plenty of time. The photovoltaic thermal system is investigated numerically through Computational Fluid Dynamics Approach using Ansys 19.0 Fluent Software. The numerical study is based on different solar irradiation at different hours. The coolant that is selected in the study is aluminum oxide () water nanofluid. The validation study between the experimental results and simulation results are achieved by examining the photovoltaic (PV) surface temperature and nanofluid outlet temperature. The maximum percentage of error between experimental and simulation results of PV surface temperature and nanofluid outlet temperature are 12.66% and 7.89%. Also, the mean average percentage error (MAPE) are computed for PV surface temperature and nanofluid outlet temperature. The results for PV surface temperature and nanofluid outlet temperature are 10.31% and 6.67%. Since the MAPE results are within 10% or error, it proved that there is good accuracy between the simulation and experimental results.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

scholarly journals CFD Study on Impeller Effect on Mixing in Miniature Stirred Tank Reactor

CFD letters ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 15-26
Author(s):  
Adnan Ghulam Mustafa ◽  
Mohd Fadhil Majnis ◽  
Nor Azyati Abdul Muttalib
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Experimental Results ◽  
Stirred Tank ◽  
Stirred Tank Reactor ◽  
Calcium Alginate Beads ◽  
Tank Reactor ◽  
Simulation Results

Mixing of fluid can happen in existence or absence of impeller which will affect the mixing performance. The hydrodynamics behavior of fluid has a strong effect on the mixing. The design of mixing systems and operation using the agitated tanks is complicated because it is difficult to obtain accurate information for turbulence’s impeller induced. Computational Fluid Dynamics can be used to provide a detailed comprehension of those systems. This paper describes the effect of various designs of impeller in miniature stirred tank reactor towards the mixing of the calcium alginate beads with the milk using Computational Fluid Dynamics (CFD) software, ANSYS Fluent 19.2. The four different type of impellers are edge beater, 5-turbine blade, t-shape, and paddle. The impeller was simulated at different speeds of 150 rpm, 250 rpm, and 300 rpm. K-epsilon turbulence model was employed to simulate the flow distribution pattern of calcium alginate beads and the Multiple Reference Frame approach was used for the impeller rotation’s simulation. The simulation results obtained have a good agreement with the experimental results in term of vortex formation. The simulation results obtained for contour plots were fitted well with the experimental results as well as with pattern of impeller flow which was also studied. As a result, an optimal design of the impeller that is able to produce good mixing can be achieved using CFD analysis. The results obtained after performing the simulation proved that edge beater blade outperformed the other impellers and took the least time to fully distribute the calcium alginate beads in the tank at 250 rpm compared to 150 and 300 rpm. It can also be concluded that the edge beater blade is the best for the mixing of two-phase fluid and also produces mixed pattern flow. The obtained results from CFD can also be used to scale up the mixing process in larger systems.

scholarly journals CFD and Experimental Analysis of a Falling Film outside Smooth and Helically Grooved Tubes

2014 ◽  
Vol 6 ◽  
pp. 915034 ◽  
Author(s):  
Cenk Onan ◽  
Derya Burcu Ozkan ◽  
Serkan Erdem
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Transfer Coefficient ◽  
Surface Temperature ◽  
Transfer Coefficient ◽  
Experimental Results ◽  
Smooth Tube ◽  
Falling Film ◽  
Grooved Tube

Simultaneous heat and mass transfer are investigated in a falling film outside grooved and smooth tubes. A numerical analysis of the helically trapezoidal-grooved and reference smooth tube was performed in the computational fluid dynamics program “Ansys Fluent 14.” The three-dimensional model drawings in the x, y, and z coordinates are used, and the effects of the falling film outside the helically grooved tube on the surface temperature and surface heat transfer coefficient are determined. The average surface temperature, heat transfer coefficient, and Nu values are determined experimentally for a constant heat flux. An uncertainty analysis and Nu correlation for the grooved tube are also provided in this study. The Reynolds number varied between 50 and 350 for the falling film and between 1500 and 3500 for air. Using a computational fluid dynamics (CFD) analysis for the reference smooth tube, the experimental results are validated within 2–12% difference. The experimental results are also within 6–13% of the grooved tubes.

scholarly journals A Comparison Among Different Parameters for the Design of a Photovoltaic/Thermal System Using Computational Fluid Dynamics

2016 ◽  
Vol 6 (5) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. Salami ◽  
Y. Ajabshirchi ◽  
S. Abdollahpoor ◽  
H. Behfar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamics Simulation ◽  
Thermal System ◽  
Computational Fluid Dynamics Simulation ◽  
Cell Temperature ◽  
Velocity Magnitude ◽  
Photovoltaic Thermal System ◽  
Fluent Software ◽  
Maximum Cell

The purpose of this paper is to compare several fins, duct height, and velocity magnitudes to acquire a PhotoVoltaic/Thermal system designed through Computational Fluid Dynamics. Simulation of different fins (rectangular, trapezoidal, curved, and pin) with different distances among fins is performed in Fluent software. The parameters such as duct height (4, 6, 8, and 10 centimeters) and velocity magnitudes (0.5, 1, 2, and 3 m/s) are also simulated. According to the results the highest cell temperature was 51°C at 0.5 m/s, while the best result was 33°C achieved with 4 cm duct height, rectangular fin and 3 m/s velocity magnitude. The findings suggest that the maximum cell temperature at the rate of 0.5 m/s is 51 °C, whereas temperature conducive to the best outputs is 33 °C. Differences among the cell temperatures through the various duct and the different fin types were significant at 1% level, also velocity magnitude would be cardinal at 1% level. A logarithmic regression model has been proposed to getting the cell temperature estimated by velocity magnitude.

Transient Computational Fluid Dynamics/Discrete Element Method Simulation of Gas–Solid Flow in a Spouted Bed and Its Validation by High-Speed Imaging Experiment

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Ling Zhou ◽  
Lingjie Zhang ◽  
Weidong Shi ◽  
Ramesh Agarwal ◽  
Wei Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Discrete Element Method ◽  
Fluidized Bed ◽  
High Speed ◽  
Discrete Element ◽  
Bubble Shape ◽  
High Speed Imaging ◽  
Bed Height ◽  
Simulation Results

A coupled computational fluid dynamics (CFD)/discrete element method (DEM) is used to simulate the gas–solid two-phase flow in a laboratory-scale spouted fluidized bed. Transient experimental results in the spouted fluidized bed are obtained in a special test rig using the high-speed imaging technique. The computational domain of the quasi-three-dimensional (3D) spouted fluidized bed is simulated using the commercial CFD flow solver ANSYS-fluent. Hydrodynamic flow field is computed by solving the incompressible continuity and Navier–Stokes equations, while the motion of the solid particles is modeled by the Newtonian equations of motion. Thus, an Eulerian–Lagrangian approach is used to couple the hydrodynamics with the particle dynamics. The bed height, bubble shape, and static pressure are compared between the simulation and the experiment. At the initial stage of fluidization, the simulation results are in a very good agreement with the experimental results; the bed height and the bubble shape are almost identical. However, the bubble diameter and the height of the bed are slightly smaller than in the experimental measurements near the stage of bubble breakup. The simulation results with their experimental validation demonstrate that the CFD/DEM coupled method can be successfully used to simulate the transient gas–solid flow behavior in a fluidized bed which is not possible to simulate accurately using the granular approach of purely Euler simulation. This work should help in gaining deeper insight into the spouted fluidized bed behavior to determine best practices for further modeling and design of the industrial scale fluidized beds.

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