Nusselt number correlation for a jacketed stirred tank using computational fluid dynamics

2018 ◽  
Vol 97 (2) ◽  
pp. 586-593 ◽  
Author(s):  
Silvia Araujo Daza ◽  
Ronald Jaimes Prada ◽  
José R. Nunhez ◽  
Guilherme J. Castilho
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nusselt Number ◽  
Stirred Tank ◽  
Nusselt Number Correlation

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.

Effect of impeller on sinking and floating behavior of suspending particle materials in stirred tank: A computational fluid dynamics and factorial design study

2017 ◽  
Vol 28 (4) ◽  
pp. 1159-1169 ◽  
Author(s):  
Yuan Zhang ◽  
Guangren Yu ◽  
Muhammad Abdul Hanan Siddhu ◽  
Abro Masroor ◽  
Muhammad Furqan Ali ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Factorial Design ◽  
Stirred Tank ◽  
Design Study ◽  
Sinking And Floating

Computational Fluid Dynamics Modeling of Impinging Gas-Jet Systems: I. Assessment of Eddy Viscosity Models

2005 ◽  
Vol 127 (4) ◽  
pp. 691-703 ◽  
Author(s):  
M. Coussirat ◽  
J. van Beeck ◽  
M. Mestres ◽  
E. Egusguiza ◽  
J.-M. Buchlin ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nusselt Number ◽  
Eddy Viscosity ◽  
Gas Jet ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Mean Values ◽  
Viscosity Models ◽  
Good Agreement

Computational fluid dynamics plays an important role in engineering design. To gain insight into solving problems involving complex industrial flows, such as impinging gas-jet systems (IJS), an evaluation of several eddy viscosity models, applied to these IJS has been made. Good agreement with experimental mean values for the field velocities and Nusselt number was obtained, but velocity fluctuations and local values of Nusselt number along the wall disagree with the experiments in some cases. Experiments show a clear relation between the nozzle-to-plate distance and the Nusselt number at the stagnation point. Those trends were only reproduced by some of the numerical experiments. The conclusions of this study are useful in the field of heat transfer predictions in industrial IJS devices, and therefore for its design.

Parametric numerical study and optimization of mass transfer and bubble size distribution in a gas-liquid stirred tank bioreactor equipped with Rushton turbine using computational fluid dynamics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sanaz Salehi ◽  
Amir Heydarinasab ◽  
Farshid Pajoum Shariati ◽  
Ali Taghvaie Nakhjiri ◽  
Kourosh Abdollahi
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Transfer Coefficient ◽  
Size Distribution ◽  
Bubble Size ◽  
Bubble Size Distribution ◽  
Stirred Tank ◽  
Operating Parameters ◽  
Stirred Tank Bioreactor

Abstract Designing and optimizing a bioreactor can be an especially challenging process. Computational modelling is an effective tool to investigate the effects of various operating parameters on bioreactor performance and identify the optimum ones. In this work, a computational fluid dynamics-population balance model (CFD-PBM) was developed to elucidate the effect of different geometrical and operating parameters on the hydrodynamics and mass transfer coefficient of a batch stirred tank bioreactor. The validated model was projected to predict the effect of different parameters including the gas flow rate, the impeller off-bottom clearance, the number of agitator blades, and rotational speed of the impeller on the velocity profiles, air volume fraction, bubble size distribution, and the local gas mass transfer coefficient (K l a) in the bioreactor. Air bubble breakup and coalescence phenomena were considered in all simulations. Factorial experimental design approach was employed to statistically investigate the impacts of the aforementioned operating and geometrical parameters on K l a and bubble size distribution in the bioreactor in order to determine the most significant parameters. This can give an essential insight into the most impactful factors when it comes to designing and scaling up a bioreactor.

scholarly journals Heat Transfer Enhancement and Flow Physics Behavior of Fluid in Circular Tube with Insert

2019 ◽  
Vol 8 (3) ◽  
pp. 1708-1715
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Flow Behavior ◽  
Vortex Generator ◽  
Leading Edge ◽  
Working Fluid ◽  
Literature Study

The paper presents computational fluid dynamics study of non-conventional insert vortex generator using Commercial software, to analyze the effect of vortex generator insert on heat transfer augmentation and fluid flow behavior. The study was done for Reynolds number 10000, 15000, 25000, 35000 and 45000 with working fluid as air flowing through a tube with a constant heat flux of 1000 w/m2. Current study validates the experimental results from the literature study. The heat transfer of these inserts with various geometrical arrangements viz. pitch to projected length ratio, angle of attack and height to inner diameter ratio are investigated here with the help of computational fluid dynamics software. The physical mechanism of formation and development of vortex flow from the leading edge to trailing edge of the insert is studied and it is observed that Nusselt number increases as an increment in Reynolds number. The ratio of augmented Nusselt number to smooth tube Nusselt number is found to be decreasing with increase in Reynolds number.

Sign in / Sign up

Export Citation Format

Share Document