Artificial intelligence‐based correlation: Process side heat transfer coefficient for helical coils in stirred tank reactors

Heat Transfer ◽  
2021 ◽  
Author(s):  
Chaitanya D. Moholkar ◽  
Shivam V. Vala ◽  
Channamallikarjun S. Mathpati ◽  
Aniruddha J. Joshi ◽  
Vivek S. Vitankar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Artificial Intelligence ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Stirred Tank ◽  
Stirred Tank Reactors ◽  
Helical Coils ◽  
Correlation Process

Experimental and CFD Investigations of Heat Transfer in Helical Coils for the Development of Correlations for Newtonian and Non-Newtonian Fluids in Transient State-Space Conditions

2013 ◽  
Author(s):  
Sandipan S. Pawar ◽  
Vivek K. Sunnapwar ◽  
Vivek K. Yakkundi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Turbulent Flow ◽  
Transfer Coefficient ◽  
Flow Regimes ◽  
Newtonian Fluids ◽  
Water Mixture ◽  
Glycerol Water ◽  
Laminar And Turbulent Flow ◽  
Helical Coils

Experimental studies and CFD investigations were carried out under laminar and turbulent flow regimes in isothermal steady state and non-isothermal unsteady state conditions in helical coils for Newtonian and non-Newtonian fluids. Water and glycerol-water mixture (10 and 20 % glycerol) as Newtonian fluids and dilute aqueous polymer solutions of sodium carboxymethyl cellulose (SCMC), sodium alginate (SA) as non-Newtonian fluids were used in this study. The experiments were performed for three helical coils of coil curvature ratios as 0.0757, 0.064 and 0.055 in laminar and turbulent flow regimes. For the first time, two innovative correlations to calculate Nusselt number (Nu) in terms of new dimensionless ‘M’ number, Prandtl number and coil curvature ratio under different conditions for Newtonian fluids are proposed in this paper. Third correlation of Nu vs. Graetz number (Gz) including the effects of coil curvature on heat transfer coefficient which was not considered by earlier investigators is developed based on tests conducted in laminar flow for Newtonian fluids. All these three innovative correlations developed based on experimental data which were not found in the literature. These correlations were compared with the work of earlier investigators and were found to be in good agreement. The CFD analysis for laminar and turbulent flow was carried out using the CFD package FLUENT 12.0.16. The CFD calculation results (Nui, U) for laminar and turbulent flows were compared with the experimental results, and also the work of earlier investigators was found to be in excellent agreement. Further, the effect of helix diameter on heat transfer for Newtonian and Non-Newtonian fluids are also presented in this paper and it was observed that as helix diameter increases, overall heat transfer coefficient decreases.

Computational analysis for the effect of the taper angle and helical pitch on the heat transfer characteristics of the helical cone coils

2012 ◽  
Vol 59 (3) ◽  
pp. 361-375 ◽  
Author(s):  
Mohamed Abo Elazm ◽  
Ahmed Ragheb ◽  
Ahmed Elsafty ◽  
Mohamed Teamah
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Radius Of Curvature ◽  
Dean Number ◽  
Taper Angle ◽  
Dean Vortex ◽  
Helical Coils ◽  
The Heat Transfer Coefficient

This numerical research is devoted to introducing the concept of helical cone coils and comparing the performance of helical cone coils as heat exchangers to the ordinary helical coils. Helical and spiral coils are known to have better heat and mass transfer than straight tubes, which is attributed to the generation of a vortex at the helical coil. This vortex, known as the Dean Vortex, is a secondary flow superimposed on the primary flow. The Dean number, which is a dimensionless number used in describing the Dean Vortex, is a function of Reynolds Number and the square root of the curvature ratio, so varying the curvature ratio for the same coil would vary the Dean Number. Numerical investigation based on the commercial CFD software fluent is used to study the effect of changing the structural parameters (taper angle of the helical coil, pitch and the base radius of curvature changes while the height is kept constant) on the Nusselt Number, heat transfer coefficient and coil outlet temperature. Six main coils having pipe diameters of 10 and 12.5 mm and base radius of curvature of 70, 80 and 90 mm were used in the investigation. It was found that, as the taper angle increases, both Nusselt Number and the heat transfer coefficient increase, also the pitch at the various taper angles was found to have an influence on Nusselt Number and the heat transfer coefficient. A MATLAB code was built to calculate the Nusselt Number at each coil turn, then to calculate the average Nusselt number for all of the coil turns. The MATLAB code was based on empirical correlation of Manlapaz and Churchill for ordinary helical coils. The CFD simulation results were found acceptable when compared with the MATLAB results.

Correlations for heat transfer coefficient and pressure drop in the annulus of concentric helical coils

2013 ◽  
Vol 50 (4) ◽  
pp. 583-586 ◽  
Author(s):  
Abdalla Gomaa ◽  
Wael I. A. Aly ◽  
M. Omara ◽  
Mahmoud Abdelmagied
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Helical Coils

scholarly journals Numerical study of the effects of geometric parameters and nanofluid properties on heat transfer and pressure drop in helical tubes

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Reza Faridi-khouzestani ◽  
Ashkan Ghafouri ◽  
Mahmood Halalizade
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Base Fluid ◽  
Volume Fraction ◽  
Geometric Parameters ◽  
Nanoparticle Diameter ◽  
Helical Coils

AbstractIn this research the geometric parameters and nanofluid properties effects on heat transfer and pressure drop in helical tube, by using alumina-water nanofluid as cooling fluid, are numerically investigated. Friction factor and heat transfer coefficient are calculated by considering the effects of nanofluid properties, including nanoparticle diameter, nanofluid temperature, Reynolds number, and volume fraction, on the one hand, and the impact of geometric parameters, including tube diameter, coils diameter and coils pitch, on the other hand. Numerical analysis is performed in the Ansys Fluent 19.2 software using the SST k-ω turbulence model. By increasing the nanofluid volume fraction the heat transfer coefficient and pressure drop in helical coils increase, the same as the nanoparticle diameter reduction. The reduction of nanoparticle diameter causes an enhancement of heat transfer and friction factor, the best results happen in dp = 5 nm and φ = 4%, where the it was ~ 40.64% more efficient than base fluid. This amounts for φ = 3%, φ = 2% and φ = 1% are 31.80%, 18.02% and 8.83%, respectively. Finally, the performance evaluation criteria (PEC) is compared for different cases, the maximum value was happen on φ = 4% and dp = 5 nm, which it is 1.86 times higher than the base fluid. The results indicate that the thermal efficiency of the heat exchanger improve largely by using helical coils and nanofluids, rather than the base fluid, and direct tubes. In addition, increasing coil pitch and curvature ratio enhance heat transfer and reduce friction factor.

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