scholarly journals Analysis of heat transfer in a heated tube with a different typed disc insertion

2012 ◽  
Vol 16 (1) ◽  
pp. 139-149
Author(s):  
Betül Turan ◽  
Hakan Öztop
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Finite Volume ◽  
Inclination Angle ◽  
Two Dimensional ◽  
Governing Equations ◽  
Heated Tube ◽  
Flat Side ◽  
Two Dimensional Flow

Heat transfer and fluid flow can be controlled in a tube by inserting different typed passive elements. The main objective of this study is to control heat transfer and fluid flow using cutting edged disc in pipe. Governing equations of laminar, two-dimensional flow is solved via finite volume technique. The disc is adiabatic and its thickness is 5mm. It is located into axial axis of the tube. Three cases were applied based on the type of the disc as inclination angle of the top side is 45? and 0?. Calculations were performed for different Reynolds number in the range of 335 < Re < 845. Three cases were tested based on types of discs. It is observed that each position exhibits different heat transfer ratio according to studied Reynolds number. The highest heat transfer is formed when inlet flow impinges to flat side of the cutting edged baffle.

Thermal Fluid Flow Transport Characteristics in Confined Channels With Two-Dimensional Dual Jet Impingement

2011 ◽  
Author(s):  
Caner Senkal ◽  
Shuichi Torii
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Rate ◽  
Inclination Angle ◽  
Transfer Rate ◽  
Velocity Ratio ◽  
Heated Wall ◽  
Outer Diameter ◽  
Stagnation Zone ◽  
Governing Equations

The flow and heat transfer characteristics of laminar dual circular jet impinging on a heating plate with inclined confinement surface has been investigated numerically. Governing equations in steady state are solved by a control volume based finite-difference method. The simulations have been carried out for Reynolds number (250≤Re≤418), the angle of inclination of the confined upper wall (0 ≤ θ ≤ 10), circular jet to annular jet velocity ratio (0≤VR≤2) and jet to target plate distances between 2D and 8D where D is the outer diameter of dual jet.SIMPLE algorithm was used to obtain velocity and temperature fields. Hybrid difference scheme is adopted for the discretized terms in the governing equations. The discretised equations are solved iteratively using the tridiagonal matrix algorithm line solver. Heat transfer performance along the heated wall is amplified with an increase in the velocity ratio and the Reynolds number. On the contrary, a substantial reduction in the heat transfer rate, for VR = 0.0, occurs in the stagnation zone, because the absence of the inner nozzle injection causes the recirculation in the corresponding region. The heat transfer rate in the stagnation zone is attenuated by increasing the jet nozzle to impinging plate distance. In particular, the effect of the inclination angle in the down-stream region, especially at the vicinity of outlet, is major then other effects Nusselt number distribution on the impingement plate is affected by inclined upper wall because inclination of the wall accelerates the exhaust flow. The streamwise reduction in the heat transfer rate for θ = 0° is suppressed by the presence of the inclined confinement surface and its value is intensified by the inclination angle.

scholarly journals The Influence of Different Types of Nanofluid on Thermal and Fluid Flow Performance of Liquid Cold Plate

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Pressure Drop ◽  
Volume Fraction ◽  
Cold Plate ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Different Types ◽  
Volume Method

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.

Effects of Heat Transfer During Peristaltic Transport in Nonuniform Channel With Permeable Walls

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Siddharth Shankar Bhatt ◽  
Amit Medhavi ◽  
R. S. Gupta ◽  
U. P. Singh
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Incompressible Fluid ◽  
Friction Force ◽  
Viscous Incompressible Fluid ◽  
Peristaltic Transport ◽  
Two Dimensional ◽  
Peristaltic Motion ◽  
Long Wavelength ◽  
Permeable Walls

In the present investigation, problem of heat transfer has been studied during peristaltic motion of a viscous incompressible fluid for two-dimensional nonuniform channel with permeable walls under long wavelength and low Reynolds number approximation. Expressions for pressure, friction force, and temperature are obtained. The effects of different parameters on pressure, friction force, and temperature have been discussed through graphs.

INVESTIGATION ON HEAT TRANSFER ENHANCEMENT IN A CORRUGATED FIN-AND-TUBE COMPACT HEAT EXCHANGER

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Ahmadali Gholami ◽  
Mazlan A. Wahid ◽  
Hussein A. Mohammed ◽  
A. Saat ◽  
M. Y. M. Fairus ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Pressure Loss ◽  
Boundary Layer Separation ◽  
Performance Criteria ◽  
Recirculation Region ◽  
Moderate Pressure ◽  
Compact Heat Exchangers ◽  
Heat Transfer Augmentation

Heat transfer augmentation and pressure loss penalty in the fin-and-tube compact heat exchangers (FTCHEs) with the corrugated shape as a special form of the fin are numerically investigated to improve heat transfer performance criteria in low Reynolds numbers. The corrugated fin as the newly design of fin pattern is presented in this study. The influence of applying corrugated design adjustments on the thermal and hydraulic characteristics of air flow are analyzed on the in-line tube arrangements. The performance of air-side heat transfer and fluid flow is investigated by numerical simulation for Reynolds number ranging from Re = 400 to 800 based on the tube collar diameter, with the corresponding frontal air velocity ranging from 0.35 to 0.72 m/s. The outcomes of simulation revealed that the corrugated fin could significantly improve the heat transfer augmentation of the FTCHEs with a moderate pressure loss penalty. The computational results indicated that some eddies were developed behind the fluted domain of corrugated finwhich produce some disruptions to fluid flow and enhance heat transfer compared with plain fin. The corrugated form of fins could enhance the thermal mixing of the fluid, delay the boundary layer separation, and reduce the size of the wake and the recirculation region behind tubes compared with the conventional form of the fin at the range of Reynolds number used in this study. In addition, the results showed that the average Nusselt number for the FTCHE with corrugated fin increased by 7.05–10.0% over the baseline case and the corresponding pressure loss decreased by 5.0–6.2%.

Combined Effects of Temperature and Velocity Jump on the Heat Transfer, Fluid Flow, and Entropy Generation Over a Single Rotating Disk

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
A. Arikoglu ◽  
G. Komurgoz ◽  
I. Ozkol ◽  
A. Y. Gunes
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Entropy Generation ◽  
Rotating Disk ◽  
Heat Transfer Fluid ◽  
Combined Effects ◽  
Jump Conditions ◽  
Governing Equations ◽  
Velocity Jump ◽  
Effects Of Temperature

The present work examines the effects of temperature and velocity jump conditions on heat transfer, fluid flow, and entropy generation. As the physical model, the axially symmetrical steady flow of a Newtonian ambient fluid over a single rotating disk is chosen. The related nonlinear governing equations for flow and thermal fields are reduced to ordinary differential equations by applying so-called classical approach, which was first introduced by von Karman. Instead of a numerical method, a recently developed popular semi numerical-analytical technique; differential transform method is employed to solve the reduced governing equations under the assumptions of velocity and thermal jump conditions on the disk surface. The combined effects of the velocity slip and temperature jump on the thermal and flow fields are investigated in great detail for different values of the nondimensional field parameters. In order to evaluate the efficiency of such rotating fluidic system, the entropy generation equation is derived and nondimensionalized. Additionally, special attention has been given to entropy generation, its characteristic and dependency on various parameters, i.e., group parameter, Kn and Re numbers, etc. It is observed that thermal and velocity jump strongly reduce the magnitude of entropy generation throughout the flow domain. As a result, the efficiency of the related physical system increases. A noticeable objective of this study is to give an open form solution of nonlinear field equations. The reduced recurative form of the governing equations presented gives the reader an opportunity to see the solution in open series form.

Numerical Study on Heat Transfer Characteristics From Parallel Plates With Cavities Swept by a Visco-Elastic Fluid

2010 ◽  
Author(s):  
Hiroshi Suzuki ◽  
Shinpei Maeda ◽  
Yoshiyuki Komoda
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Thermal Field ◽  
Numerical Study ◽  
Geometric Parameters ◽  
Two Dimensional ◽  
Parallel Plates ◽  
Heat Transfer Characteristics ◽  
Elastic Fluid ◽  
Heat Transfer Augmentation

Two-dimensional numerical computations have been performed in order to investigate the development characteristics of flow and thermal field in a flow between parallel plates swept by a visco-elastic fluid. In the present study, the effect of the cavity number in the domain and of Reynolds number was focused on when the geometric parameters were set constant. From the results, it is found that the flow penetration into the cavities effectively causes the heat transfer augmentation in the cavities in any cavity region compared with that of water case. It is also found that the development of thermal field in cases of the present visco-elastic fluid is quicker compared with that of water cases. The present heat transfer augmentation technique using Barus effect of a visco-elastic fluid is effective in the range of low Reynolds number.

Verification of Finite Volume Computations on Steady-State Fluid Flow and Heat Transfer

2001 ◽  
Vol 124 (1) ◽  
pp. 11-21 ◽  
Author(s):  
J. Cadafalch ◽  
C. D. Pe´rez-Segarra ◽  
R. Co`nsul ◽  
A. Oliva
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Finite Volume ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Independent Solution ◽  
Post Processing ◽  
Square Duct ◽  
Flow And Heat Transfer

This work presents a post-processing tool for the verification of steady-state fluid flow and heat transfer finite volume computations. It is based both on the generalized Richardson extrapolation and the Grid Convergence Index GCI. The observed order of accuracy and a error band where the grid independent solution is expected to be contained are estimated. The results corresponding to the following two and three-dimensional steady-state simulations are post-processed: a flow inside a cavity with moving top wall, an axisymmetric turbulent flow through a compressor valve, a premixed methane/air laminar flat flame on a perforated burner, and the heat transfer from an isothermal cylinder enclosed by a square duct. Discussion is carried out about the certainty of the estimators obtained with the post-processing procedure. They have been shown to be useful parameters in order to assess credibility and quality to the reported numerical solutions.

scholarly journals Transient free convection in an inclined square porous cavity filled with a nanofluid using LTNE and Buongiorno’s models

2018 ◽  
Vol 240 ◽  
pp. 03014
Author(s):  
Mikhail Sheremet ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Inclination Angle ◽  
Equilibrium Temperature ◽  
Brownian Diffusion ◽  
Governing Equations ◽  
Nanofluid Flow ◽  
Porous Cavity ◽  
Flow And Heat Transfer ◽  
The Finite Difference Method ◽  
Porous Enclosure

The combined effect of Brownian diffusion, thermophoresis and cavity inclination angle on natural convective heat transfer in an inclined porous enclosure has been studied numerically. Fluid containing nanoparticles of low concentration circulates inside the cavity under the effect of the buoyancy force. Governing equations with corresponding boundary conditions formulated using the non-dimensional stream function and vorticity variables have been solved by the finite difference method. An influence of the cavity inclination angle, Darcy and Nield numbers on nanofluid flow and heat transfer has been investigated. It has been found that high Nield numbers illustrate more equilibrium temperature distribution inside the porous cavity.

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