Press Forging Forming of the Round-Fin on Heat Sink

2013 ◽  
Vol 706-708 ◽  
pp. 448-451
Author(s):  
Chong Chao Lin ◽  
Ke Sheng Wang ◽  
Yu Han ◽  
Li Han Zhang
Keyword(s):  
Friction Coefficient ◽  
Friction Factor ◽  
Heat Sink ◽  
Material Flow ◽  
Extrusion Process ◽  
Metal Sheets ◽  
Flow Through ◽  
Good For

Press forging forming is a combined extrusion process for forming round-fin on heat sink on thick metal sheets. A series of simulations on the round-fin forming using the program DEFORM were carried out. The blank thickness and friction coefficient on the formation of round-fin were studied. The results show that the blank thickness is very good for the round-fin formation, and the thicker the blank is, the better the round-fin can be formed; and also when both the punch-blank interface and the die-blank interface have the same value of friction factor, the larger value of friction factor is in favor of round-fin forming, the further investigation reveals that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin.

Parallel Extrusion of Aluminum Alloy Heat Sink with Round-Fin

2013 ◽  
Vol 739 ◽  
pp. 131-135
Author(s):  
Li Han Zhang ◽  
Ke Sheng Wang ◽  
Yu Han ◽  
Jia Yu Ying
Keyword(s):  
Heat Sink ◽  
Material Flow ◽  
Extrusion Process ◽  
Element Analysis ◽  
Automotive Lighting ◽  
Metal Sheets ◽  
The Finite Element Analysis ◽  
Alloy Heat ◽  
Flow Through ◽  
Good Agreement

Parallel extrusion is a combined extrusion process for forming round-fin heat sink on thick metal sheets. In this paper, the parallel extrusion has been applied to manufacture the round-fin heat sink in the automotive lighting. Numerical simulations on the round-fin heat sink forming using the software DEFORM were carried out. The tooling structure with counterpressure on the heat sink formation was investigated. The results show that the tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, it is shown that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin, and the simulation results are in good agreement with the experimental data.

scholarly journals Optimization of the Die Topology in Extrusion Processes

2008 ◽  
Vol 43 ◽  
pp. 81-88 ◽  
Author(s):  
Thomas Kloppenborg ◽  
Marco Schikorra ◽  
Jan P. Rottberg ◽  
A. Erman Tekkaya
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Material Flow ◽  
Extrusion Process ◽  
Two Dimensional ◽  
Extrusion Dies ◽  
Porthole Die ◽  
Extrusion Die ◽  
Flow Through ◽  
The Difference

This paper presents the results of investigations on topology optimizations in extrusion dies. The change of material viscosity of finite elements in the numerical model is utilized to allow or to block the material flow through the finite elements in simplified two-dimensional extrusion models. Two different optimization procedures are presented. In the first part of the paper dead zones in a flat and in a porthole die were improved by enhance the streamlining of the extrusion die. In the second part an evolutionary optimization algorithm has been used to optimize the extrusion die topology in order to reduce the difference between the strand exit velocities in a multi extrusion process. Finally, both methods were sequentially combined.

scholarly journals Effect of lubrication and friction coefficient on temperature distribution for combined backward forward extrusion process for alloy steel

2018 ◽  
Vol 1 (1) ◽  
pp. 352-357
Author(s):  
Ban Alamer ◽  
Çetin Karataş ◽  
Faruk Mert ◽  
Haitham Aljawad
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Distribution ◽  
Numerical Analysis ◽  
Friction Coefficient ◽  
Friction Factor ◽  
Metal Forming ◽  
Extrusion Process ◽  
Forward Extrusion ◽  
Friction Factors

During extrusion process ,the effects of friction between die and workpiece are important and it is one of the most serious problems in metal forming. Friction factor has different effects depending on the size of workpiece. In this study the effect of friction factor and lubrication effects on temperature distribution , power , and load for combined backward forward extrusion process was demonstrated . A numerical analysis based on finite element method by using Q form program was used to study the effect of friction factor through two type of condition , first for lubrication three values for friction factor were used ( 0.1, 0.2 ,0.3 ) .The second condition was un lubrication , the friction factors values were (0.25 , 0.5 ,0.75) . The material of specimen was steel C45.The parts to be manufactured was wrench socket and the lubrication was done by using water and graphite .The results showed that for lubricated and un lubricated conditions , the temperatures power and load were increased when the friction factor increased .

scholarly journals Possible Chromatographie Effect of Liquid-Crystalline Permeation

1973 ◽  
Vol 28 (12) ◽  
pp. 1967-1968 ◽  
Author(s):  
W. Helfrich
Keyword(s):  
Material Flow ◽  
Liquid Crystalline ◽  
Permeation Rate ◽  
Flow Through

Permeation, i. e. material flow through cholesteric and smectic layers, may vary in speed for the components of a mixture. We derive qualitative formulas for the permeation rate of solute molecules in cholesterics as a function of their size. The possibility of a new kind of chromatography based on permeation in cholesterics or smectics is discussed.

Turbulent Heat and Momentum Transports in an Infinite Rod Array

1987 ◽  
Vol 109 (3) ◽  
pp. 599-605 ◽  
Author(s):  
An-Shik Yang ◽  
Ching-Chang Chieng
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Equation Model ◽  
Temperature Fields ◽  
Turbulent Heat ◽  
Fluid Temperature ◽  
Transfer Coefficients ◽  
Anisotropic Factor ◽  
Flow Through ◽  
Rod Array

An anisotropic factor is carefully selected from eleven distributions and adopted to the k–ε two-equation model of turbulence to obtain detailed velocity and temperature fields for steady-state, fully developed turbulent flow through infinite triangular/square rod array. The present study covers the ranges of pitch-to-diameter ratio from 1.123 to 1.5, and Reynolds number from 2.4 × 104 to 106. Velocity and wall shear stress are calculated and compared to experimental data. Normalized fluid temperature, friction factor, and heat transfer coefficient are also computed. The correlations of friction factor and heat transfer coefficients for flow inside circular pipe and flow through finite rod arrays are compared with the results for flow through infinite rod arrays.

scholarly journals Study of Mini Channel Heat Sink with Different Internal Configuration

2020 ◽  
Vol 319 ◽  
pp. 02004
Author(s):  
Muhammad Akif Rahman ◽  
Md Badrath Tamam ◽  
Md Sadman Faruque ◽  
A.K.M. Monjur Morshed
Keyword(s):  
Nusselt Number ◽  
Thermal Performance ◽  
Heat Sink ◽  
Rectangular Channel ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Rectangular Channels ◽  
Flow Through ◽  
Internal Configuration

In this paper a numerical analysis of three-dimensional laminar flow through rectangular channel heat sinks of different geometric configuration is presented and a comparison of thermal performance among the heat sinks is discussed. Liquid water was used as coolant in the aluminum made heat sink with a glass cover above it. The aspect ratio (section height to width) of rectangular channels of the mini-channel heat sink was 0.33. A heat flux of 20 W/cm2 was continuously applied at the bottom of the channel with different inlet velocity for Reynold’s number ranging from 150 to 1044. Interconnectors and obstacles at different positions and numbers inside the channel were introduced in order to enhance the thermal performance. These modifications cause secondary flow between the parallel channels and the obstacles disrupt the boundary layer formation of the flow inside the channel which leads to the increase in heat transfer rate. Finally, Nusselt number, overall thermal resistance and maximum temperature of the heat sink were calculated to compare the performances of the modified heat sinks with the conventional mini channel heat sink and it was observed that the heat sink with both interconnectors and obstacles enhanced the thermal performance more significantly than other configurations. A maximum of 36% increase in Nusselt number was observed (for Re =1044).

Influence of Heating Models on Necking Deformation during Tube Extrusion Process

2011 ◽  
Vol 189-193 ◽  
pp. 1778-1781 ◽  
Author(s):  
Gui Hua Liu ◽  
Yong Qiang Guo ◽  
Zhi Jiang
Keyword(s):  
Temperature Gradient ◽  
Material Flow ◽  
Extrusion Process ◽  
Work Piece ◽  
Tube Extrusion ◽  
Deformation Parameters ◽  
Flow Features ◽  
Extrusion Forming ◽  
3D Software ◽  
Deform 3D

By using Deform-3D software, the necking extrusion forming processes of integer trailer axle with two different heating means which are Uniform Heating (UH) method and Partly Heating (PH) method with temperature gradient are simulated. The influence of deformation parameters such as friction factor, necking coefficient, different temperature distribution of work-piece on the material flow features, stress and strain field, loading force and deformation process are analyzed in detail. According to the numerical simulation results, using PH method with temperature gradient can improve necking deformation during tube extrusion process.

scholarly journals Unsteady mixed convection flow through a permeable stretching flat surface with partial slip effects through MHD nanofluid using spectral relaxation method

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 323-334 ◽  
Author(s):  
Sami M. Ahamed ◽  
Sabyasachi Mondal ◽  
Precious Sibanda
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Flat Surface ◽  
Internal Heat ◽  
Relaxation Method ◽  
Skin Friction Coefficient ◽  
Partial Slip ◽  
Spectral Relaxation Method ◽  
Flow Through ◽  
Spectral Relaxation

AbstractAn unsteady, laminar, mixed convective stagnation point nanofluid flow through a permeable stretching flat surface using internal heat source or sink and partial slip is investigated. The effects of thermophoresis and Brownian motion parameters are revised on the traditional model of nanofluid for which nanofluid particle volume fraction is passively controlled on the boundary. Spectral relaxation method is applied here to solve the non-dimensional conservation equations. The results show the illustration of the impact of skin friction coefficient, different physical parameters, and the heat transfer rate. The nanofluid motion is enhanced with increase in the value of the internal heat sink or source. On the other hand, the rate of heat transfer on the stretching sheet and the skin friction coefficient are reduced by an increase in internal heat generation. This study further shows that the velocity slip increases with decrease in the rate of heat transfer. The outcome results are benchmarked with previously published results.

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