Numerical analysis of heat transfer enhancement of fluid past an oscillating circular cylinder in laminar flow regime

2021 ◽  
Vol 139 ◽  
pp. 103853
Author(s):  
Xiangyu Luo ◽  
Weichen Zhang ◽  
Haitao Dong ◽  
Amrit Kumar Thakur ◽  
Bing Yang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Laminar Flow ◽  
Circular Cylinder ◽  
Heat Transfer Enhancement ◽  
Flow Regime ◽  
Transfer Enhancement ◽  
Laminar Flow Regime

Design of a Microfin Array Heat Sink Using Flow-Induced Vibration to Enhance the Heat Transfer Rate in the Laminar Flow Regime

2001 ◽  
Author(s):  
Jeung Sang Go ◽  
Geunbae Lim ◽  
Hayong Yun ◽  
Sung Jin Kim ◽  
Inseob Song
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Heat Transfer Enhancement ◽  
Flow Regime ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Transfer Enhancement ◽  
Air Velocity ◽  
Flow Induced Vibration

Abstract This paper presented design guideline of the microfin array heat sink using flow-induced vibration to increase the heat transfer rate in the laminar flow regime. Effect of the flow-induced vibration of a microfin array on heat transfer enhancement was investigated experimentally by comparing the thermal resistances of the microfin array heat sink and those of a plain-wall heat sink. At the air velocities of 4.4m/s and 5.5 m/s, an increase of 5.5% and 11.5% in the heat transfer rate was obtained, respectively. The microfin flow sensor also characterized the flow-induced vibration of the microfin. It was determined that the microfin vibrates with the fundamental natural frequency regardless of the air velocity. It was also shown that the vibrating displacement of the microfin is increased with increasing air velocity and then saturated over a certain value of air velocity. Based on the numerical analysis of the temperature distribution resulted from microfin vibration and experimental results, a simple heat transfer model (heat pumping model) was proposed to understand the heat transfer mechanism of a microfin array heat sink. Under the geometric and structural constraints, the maximum heat transfer enhancement was obtained at the intersection of the minimum thickness of the microfin and constraint of the bending angle.

Numerical Analysis of Convective Heat Transfer of Nanofluids for Laminar Flow in a Circular Tube

2012 ◽  
Author(s):  
Oguz Kirez ◽  
Almila Yazicioglu ◽  
Sadik Kakac
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Laminar Flow ◽  
Boundary Conditions ◽  
Heat Transfer Enhancement ◽  
Viscous Dissipation ◽  
Particle Diameter ◽  
Transfer Enhancement ◽  
Circular Duct ◽  
Axial Conduction

In this study, a numerical analysis of heat transfer enhancement of Alumina/water nanofluid in a steady-state, single-phase, laminar flow in a circular duct is presented for the case of constant wall heat flux and constant wall temperature boundary conditions. The analysis is performed with a newly suggested model (Corcione) for effective thermal conductivity and viscosity, which show the effects of temperature and nanoparticle diameter. The results for Nusselt number and heat transfer enhancement are presented in graphical and tabular forms, for a given Peclet number, nanoparticle volumetric fraction, and particle diameter in the thermal entrance region. The results are compared with the experimental results available in the literature under the same conditions and a good agreement is found. The two boundary conditions are compared and slightly differing results are discussed. Finally, the effect of the axial conduction and viscous dissipation are investigated. The axial conduction effect is found to be negligible for practical cases while the viscous dissipation effect is found to be significantly important depending on the boundary conditions and the pipe diameter.

Experimental and Numerical Analysis of Convective Heat Transfer of Alumina Nanofluids Under Laminar Flow Regime

2013 ◽  
Vol 10 (10) ◽  
pp. 2305-2311 ◽  
Author(s):  
Hafizur Rehman ◽  
Md. J. Nine ◽  
Handry Afrianto ◽  
J. H. Kim ◽  
Hanshik Chung ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Laminar Flow ◽  
Convective Heat Transfer ◽  
Flow Regime ◽  
Convective Heat ◽  
Laminar Flow Regime

Heat transfer enhancement using second mode self-oscillating structures

2019 ◽  
Vol 30 (7) ◽  
pp. 3827-3842
Author(s):  
Samer Ali ◽  
Zein Alabidin Shami ◽  
Ali Badran ◽  
Charbel Habchi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Laminar Flow ◽  
Flow Regime ◽  
Vortex Generator ◽  
Reynolds Numbers ◽  
Content Type ◽  
Laminar Flow Regime ◽  
Second Mode

Purpose In this paper, self-sustained second mode oscillations of flexible vortex generator (FVG) are produced to enhance the heat transfer in two-dimensional laminar flow regime. The purpose of this study is to determine the critical Reynolds number at which FVG becomes more efficient than rigid vortex generators (RVGs). Design/methodology/approach Ten cases were studied with different Reynolds numbers varying from 200 to 2,000. The Nusselt number and friction coefficients of the FVG cases are compared to those of RVG and empty channel at the same Reynolds numbers. Findings For Reynolds numbers higher than 800, the FVG oscillates in the second mode causing a significant increase in the velocity gradients generating unsteady coherent flow structures. The highest performance was obtained at the maximum Reynolds number for which the global Nusselt number is improved by 35.3 and 41.4 per cent with respect to empty channel and rigid configuration, respectively. Moreover, the thermal enhancement factor corresponding to FVG is 72 per cent higher than that of RVG. Practical implications The results obtained here can help in the design of novel multifunctional heat exchangers/reactors by using flexible tabs and inserts instead of rigid ones. Originality/value The originality of this paper is the use of second mode oscillations of FVG to enhance heat transfer in laminar flow regime.

Heat Transfer in Internal Flows of Non-Linear Fluids: A Review

2006 ◽  
Author(s):  
Dennis A. Siginer ◽  
Mario F. Letelier
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Heat Transfer Enhancement ◽  
Polymer Solutions ◽  
Single Mode ◽  
Secondary Flows ◽  
Transfer Enhancement ◽  
Experimental Heat ◽  
Aqueous Polymer ◽  
Non Linear

A survey of the developments in heat transfer studies of non-linear inelastic as well as elastic fluids in tubes is given. Experimental findings concerning heat transfer enhancement characteristics of viscoelastic aqueous polymer solutions are very significant. Specifically, it is reported that heat transfer results for viscoelastic aqueous polymer solutions are drastically higher than those found for water in laminar flow in rectangular ducts. A number of investigators suggested that the high experimental heat transfer values were due to secondary flows resulting from the elasticity of the fluids. In this context recent results concerning the fully developed thermal field in constant pressure gradient driven laminar flow of a class of viscoelastic fluids characterized by single mode, non-affine constitutive equations in straight pipes of arbitrary contour ∂D is reviewed. Heat transfer enhancement due to shear-thinning is identified together with the enhancement due to the inherent elasticity of the fluid. The latter is the result of secondary flows in the cross-section. Increasingly large enhancements are computed with increasing elasticity of the fluid as compared to its Newtonian counterpart. Large enhancements are possible even with dilute fluids. Isotherms for the temperature field are presented and discussed for several non-circular contours such as the ellipse and the equilateral triangle together with heat transfer behavior in terms of the Nusselt number Nu.

scholarly journals NUMERICAL ANALYSIS OF HEAT TRANSFER ENHANCEMENT IN CONICAL-NOZZLE TURBULATORS INSERTED TUBE

2018 ◽  
Vol 13 (1) ◽  
pp. 7-17
Author(s):  
Sibel Güneş ◽  
Toygun Dağdevir ◽  
Orhan Keklikcioğlu ◽  
Veysel Özceyhan
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Heat Transfer Enhancement ◽  
Conical Nozzle ◽  
Transfer Enhancement
Sign in / Sign up

Export Citation Format

Share Document