Numerical Simulations of Heat Transfer Performance of Taylor–Couette Flow in Slit Model

2021 ◽  
Author(s):  
Si-liang Sun ◽  
Dong Liu ◽  
Wei-Dong Shi ◽  
Ying-Ze Wang ◽  
Hyoung-Bum Kim
Keyword(s):  
Heat Transfer ◽  
Numerical Simulations ◽  
Couette Flow ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Taylor Couette ◽  
Taylor Couette Flow

Numerical Simulations of Heat Transfer in Taylor-Couette Flow

1998 ◽  
Vol 120 (1) ◽  
pp. 65-71 ◽  
Author(s):  
R. Kedia ◽  
M. L. Hunt ◽  
T. Colonius
Keyword(s):  
Heat Transfer ◽  
Numerical Simulations ◽  
Couette Flow ◽  
Stokes Equations ◽  
Taylor Vortex ◽  
Cylinder Surface ◽  
Stable States ◽  
Grashof Number ◽  
Taylor Couette ◽  
Taylor Couette Flow

Numerical simulations have been performed to study the effects of the gravitational and the centrifugal potentials on the stability of heated, incompressible Taylor-Couette flow. The flow is confined between two differentially heated, concentric cylinders, and the inner cylinder is allowed to rotate. The Navier-Stokes equations and the coupled energy equation are solved using a spectral method. To validate the code, comparisons are made with existing linear stability analysis and with experiments. The code is used to calculate the local and average heat transfer coefficients for a fixed Reynolds number (Re = 100) and a range of Grashof numbers. The investigation is primarily restricted to radius ratios 0.5 and 0.7 for fluids with Prandtl number of about 0.7. The variation of the local coefficients of heat transfer on the cylinder surface is investigated, and maps showing different stable states of the flow are presented. Results are also presented in terms of the equivalent conductivity, and show that heat transfer decreases with Grashof number in axisymmetric Taylor vortex flow regime, and increases with Grashof number after the flow becomes nonaxisymmetric.

Heat Transfer Enhancement in Axial Taylor-Couette Flow

2005 ◽  
Author(s):  
S. Gilchrist ◽  
C. Y. Ching ◽  
D. Ewing
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Couette Flow ◽  
Reynolds Numbers ◽  
Taylor Number ◽  
Number Range ◽  
Taylor Couette ◽  
Number Case ◽  
Taylor Couette Flow

An experimental investigation was performed to determine the effect that surface roughness has on the heat transfer in an axial Taylor-Couette flow. The experiments were performed using an inner rotating cylinder in a stationary water jacket for Taylor numbers of 106 to 5×107 and axial Reynolds numbers of 900 to 2100. Experiments were performed for a smooth inner cylinder, a cylinder with two-dimensional rib roughness and a cylinder with three-dimensional cubic protrusions. The heat transfer results for the smooth cylinder were in good agreement with existing experimental data. The change in the Nusselt number was relatively independent of the axial Reynolds number for the cylinder with rib roughness. This result was similar to the smooth wall case but the heat transfer was enhanced by 5% to 40% over the Taylor number range. The Nusselt number for the cylinder with cubic protrusions exhibited an axial Reynolds number dependence. For a low axial Reynolds number of 980, the Nusselt number increased with the Taylor number in a similar way to the other test cylinders. At higher axial Reynolds numbers, the heat transfer was initially independent of the Taylor number before increasing with Taylor number similar to the lower Reynolds number case. In this higher axial Reynolds number case the heat transfer was enhanced by up to 100% at the lowest Taylor number of 1×106 and by approximately 35% at the highest Taylor number of 5×107.

Heat Transfer in a Taylor-Couette Flow

2017 ◽  
Author(s):  
Vinicius Malatesta ◽  
Vinícius Hagemeyer Chiumento
Keyword(s):  
Heat Transfer ◽  
Couette Flow ◽  
Taylor Couette ◽  
Taylor Couette Flow

Bursting dynamics due to a homoclinic cascade in Taylor–Couette flow

2008 ◽  
Vol 613 ◽  
pp. 357-384 ◽  
Author(s):  
J. ABSHAGEN ◽  
J. M. LOPEZ ◽  
F. MARQUES ◽  
G. PFISTER
Keyword(s):  
Numerical Simulations ◽  
Couette Flow ◽  
Large Scale ◽  
Nonlinear Dynamical Systems ◽  
Low Frequency ◽  
Accumulation Point ◽  
Infinite Length ◽  
Phase Dynamics ◽  
Taylor Couette ◽  
Taylor Couette Flow

Transitions between regular oscillations and bursting oscillations that involve a bifurcational process which culminates in the creation of a relative periodic orbit of infinite period and infinite length are investigated both experimentally and numerically in a short-aspect-ratio Taylor–Couette flow. This bifurcational process is novel in that it is the accumulation point of a period-adding cascade at which the mid-height reflection symmetry is broken. It is very rich and complex, involving very-low-frequency states arising via homoclinic and heteroclinic dynamics, providing the required patching between states with very different dynamics in neighbouring regions of parameter space. The use of nonlinear dynamical systems theory together with symmetry considerations has been crucial in interpreting the laboratory experimental data as well as the results from the direct numerical simulations. The phenomenon corresponds to dynamics well beyond the first few bifurcations from the basic state and so is beyond the reach of traditional hydrodynamic stability analysis, but it is not fully developed turbulence where a statistical or asymptotic approach could be employed. It is a transitional phenomenon, where the phase dynamics of the large-scale structures (jets of angular momentum emanating from the boundary layer on the rotating inner cylinder) becomes complicated. Yet the complicated phase dynamics remains accessible to an analysis of its space–time characteristics and a comprehensive mechanical characterization emerges. The excellent agreement between the experiments and the numerical simulations demonstrates the robustness of this complex bifurcation phenomenon in a physically realized system with its inherent imperfections and noise. Movies are available with the online version of the paper.

scholarly journals Numerical study of heat flow characteristics of turbulent Taylor-Couette flow in slit wall mode

2021 ◽  
Vol 9 ◽  
Author(s):  
Dong Liu ◽  
◽  
Mohammed Mohammedsalih ◽  
Amponsah-Gyenin Nana Kofi ◽  
Shi-cheng Ding ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Couette Flow ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Industrial Applications ◽  
Small Scale ◽  
Taylor Couette ◽  
Taylor Couette Flow

Heat transfer enhancement is by far an important component in the design of numerous industrial applications of Taylor-Couette flow including electric motors and particularly rotating machinery. To optimize the performances of these machines, superior knowledge of the fluid flow is vital to better estimate the heat transfer distribution. This study will specifically consider the effect the slit number and width possess on the distribution of turbulent Taylor-Couette flow and the resulting heat transfer correlation in the annulus of two concentric cylinders under varying conditions. A numerical simulation method is intended for the study using varying slit structure parameters of widths (2.5 ≤ w ≤ 7.5) mm and fitted with 6, 9 and 12 number of slits. The slit effect is then investigated under both isotherm and non-isotherm conditions considering the interactions between fluid flow regions in the mainstream area and the annulus. The small-scale vortex that appears in the annulus region improves the heat transferability between the fluid in the annulus and the main region as well as the heat transfer performance of the model with a gradual increase in Reynolds number.

Studying the Effect of Porosity of Porous Layer Coating on the Performance of the Horizontal Tubular Falling Film Evaporator

2021 ◽  
Author(s):  
Alaa Adel Ibrahim ◽  
Hassan Elgamal ◽  
Ahmed M. Nagib Elmekawy
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Numerical Simulations ◽  
Thermal Performance ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Falling Film ◽  
Film Evaporator ◽  
Porosity Ratio ◽  
Layer Coating

Abstract Through the recent decades, many studies have focused on finding efficient methods to enhance the heat transfer performance in heat exchangers. Therefore, using porous media attracted many researchers, as it is such a simple, efficient, and low-cost technique in enlarging the surface contact area of heat transfer through the fluid pass. Nevertheless, there is little work associated with using porous media to enhance the thermal performance of falling film evaporators. The present study seeks to discuss numerically the liquid flow behaviour over falling film evaporator tubes in the case of bare tubes and tubes with porous layer coating. The two-dimensional multi-phase numerical simulations are also carried out in order to investigate the effect of the porosity ratio of the porous medium added to the tubes in the heat transfer performance. Furthermore, deducing the way to select a decent porosity ratio to be used to get the best thermal performance is demonstrated through the study. Time-averaged results gained from the numerical simulations have been compared to those of bare-tube falling film evaporator to observe much higher heat transfer performance represented in the average surface Nusselt number (Nu) which increased by 3 times.

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