scholarly journals Performance Assessment of a Three-Dimensional Printed Porous Media Produced by Selective Laser Melting Technology for the Optimization of Loop Heat Pipe Wicks

2019 ◽  
Vol 9 (14) ◽  
pp. 2905 ◽  
Author(s):  
Jesús Esarte ◽  
Jesús M. Blanco ◽  
Angela Bernardini ◽  
Ramón Sancibrián
Keyword(s):  
Heat Pipe ◽  
Selective Laser Melting ◽  
Three Dimensional ◽  
Loop Heat Pipe ◽  
High Permeability ◽  
Laser Melting ◽  
Powder Sintering ◽  
Sintered Copper ◽  
Wick Structure ◽  
Better Than

The primary wick in a loop heat pipe device is a key component that is central to the operation of the device. Both high permeability and capillary pumping capacity, two properties highly dependent on wick structure, are strongly desirable for a satisfactory thermal performance. In this paper, selective laser melting (SLM), a three-dimensional (3D) printing technology, is used to create a primary wick for an 80 W heat transfer application. The permeability and capillarity values of this wick, experimentally measured, are compared with those built with the most widely used technologies nowadays, such as powder sintering and meshes. In this study, the SLM scaffold is shown to satisfy the minimum values required by the application in terms of capillarity and permeability: 0.031 mm/s and 4 × 10−12 m2, respectively. Our comparative study revealed that the wick produced with the SLM technology presented higher values of permeability, by two orders of magnitude, and slightly higher capillary figures than those corresponding to powder sintering for such application. However, it had capillary values well below those of a stainless-steel mesh. The hydraulic behavior of the SLM wick was better than that of the sintered copper powder, because it not only met the above-mentioned specifications, but it also improved its performance.

Biporous Sintered Copper for Closed Loop Heat Pipe Evaporator

2005 ◽  
Author(s):  
Tadej Semenic ◽  
Ying-Yu Lin ◽  
Ivan Catton
Keyword(s):  
Heat Flux ◽  
Heat Pipe ◽  
Atmospheric Pressure ◽  
Closed Loop ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Copper Base ◽  
Sintered Copper ◽  
Wick Structure ◽  
Heat Loads

Parameters that determine a critical heat flux (CHF) inside a biporous evaporator (wick) for a closed loop heat pipe have been studied. In a present work, a biporous wick structure was sintered from copper powder 53–63μm diameter into clusters 500–710μm diameter; the clusters were then sintered into 20mm long and 3mm wide wicks with different wick thickness on copper bases with three different lengths (5mm, 7.5mm and 10mm). Total of six wicks were made and tested. Copper base(mm) to wick thickness(mm) ratios of the wicks tested are: 5/5, 7.5/5, 10/5, 5/3, 7.5/3 and 10/1.5. Narrow (3mm) wicks with different copper base lengths allowed sidewise observation of the boiling inside the wick at different heat loads. Best-performed 10/1.5 wick, second best was 5/3 and then following 7.5/3, 5/5, 7.5/5, 10/5. Tests were run at atmospheric pressure and absolute ethanol as working fluid.

Fabrication of three-dimensional connected W-Cu10Sn composites by selective laser melting

2020 ◽  
Vol 264 ◽  
pp. 127377 ◽  
Author(s):  
Zhenlu Zhou ◽  
Zhen Tan ◽  
Dingyong He ◽  
Zheng Zhou ◽  
Li Cui ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Three Dimensional ◽  
Laser Melting

Development and tests of loop heat pipe with multi-layer metal foams as wick structure

2016 ◽  
Vol 94 ◽  
pp. 324-330 ◽  
Author(s):  
Wei Zhou ◽  
Weisong Ling ◽  
Lian Duan ◽  
K.S. Hui ◽  
K.N. Hui
Keyword(s):  
Heat Pipe ◽  
Metal Foams ◽  
Loop Heat Pipe ◽  
Wick Structure

Novel Fluorescent Visualization Method to Characterize Transport Properties in Micro/Nano Heat Pipe Wick Structures

2009 ◽  
Author(s):  
Pramod Chamarthy ◽  
H. Peter J. de Bock ◽  
Boris Russ ◽  
Shakti Chauhan ◽  
Brian Rush ◽  
...  
Keyword(s):  
Heat Pipe ◽  
High Performance ◽  
Gravitational Force ◽  
Driving Forces ◽  
Electronics Cooling ◽  
Heat Pipes ◽  
High Permeability ◽  
Permeability Characteristics ◽  
Wick Structure ◽  
Initial Results

Heat pipes have been gaining a lot of popularity in electronics cooling applications due to their ease of operation, reliability, and high effective thermal conductivity. An important component of a heat pipe is the wick structure, which transports the condensate from condenser to evaporator. The design of wick structures is complicated by competing requirements to create high capillary driving forces and maintain high permeability. While generating large pore sizes will help achieve high permeability, it will significantly reduce the wick’s capillary performance. This study presents a novel experimental method to simultaneously measure capillary and permeability characteristics of the wick structures using fluorescent visualization. This technique will be used to study the effects of pore size and gravitational force on the flow-related properties of the wick structures. Initial results are presented on wick samples visually characterized from zero to nine g acceleration on a centrifuge. These results will provide a tool to understand the physics involved in transport through porous structures and help in the design of high performance heat pipes.

scholarly journals Fabrication Of Scaffolds From Ti6Al4V Powders Using The Computer Aided Laser Method

2015 ◽  
Vol 60 (2) ◽  
pp. 1065-1070 ◽  
Author(s):  
L.A. Dobrzański ◽  
A.D. Dobrzańska-Danikiewicz ◽  
P. Malara ◽  
T.G. Gaweł ◽  
L.B. Dobrzański ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
3D Model ◽  
Three Dimensional ◽  
Plaster Cast ◽  
Laser Melting ◽  
Laser Method ◽  
Porous Implant ◽  
Unit Cells ◽  
Dimensional Shape ◽  
3D Solid

AbstractThe aim of the research, the results of which are presented in the paper, is to fabricate, by Selective Laser Melting (SLM), a metallic scaffold with Ti6Al4V powder based on a virtual model corresponding to the actual loss of a patient’s craniofacial bone. A plaster cast was made for a patient with a palate recess, and the cast was then scanned with a 3D scanner to create a virtual 3D model of a palate recess, according to which a 3D model of a solid implant was created using specialist software. The virtual 3D solid implant model was converted into a 3D porous implant model after designing an individual shape of the unit cell conditioning the size and three-dimensional shape of the scaffold pores by multiplication of unit cells. The data concerning a virtual 3D porous implant model was transferred into a selective laser melting (SLM) device and a metallic scaffold was produced from Ti6Al4V powder with this machine, which was subjected to surface treatment by chemical etching. An object with certain initially adopted assumptions, i.e. shape and geometric dimensions, was finally achieved, which perfectly matches the patient bone recesses. The scaffold created was subjected to micro-and spectroscopic examinations.

Experimental Investigation of the Miniature Loop Heat Pipe With Flat Evaporator

2005 ◽  
Author(s):  
Randeep Singh ◽  
Aliakbar Akbarzadeh ◽  
Masataka Mochizuki ◽  
Thang Nguyen ◽  
Vijit Wuttijumnong
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Thermal Control ◽  
Capillary Forces ◽  
High Heat ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Wick Structure ◽  
Flat Evaporator ◽  
Heat Loads

Loop heat pipe (LHP) is a very versatile heat transfer device that uses capillary forces developed in the wick structure and latent heat of evaporation of the working fluid to carry high heat loads over considerable distances. Robust behaviour and temperature control capabilities of this device has enable it to score an edge over the traditional heat pipes. In the past, LHPs has been invariably assessed for electronic cooling at large scale. As the size of the thermal footprint and available space is going down drastically, miniature size of the LHP has to be developed. In this paper, results of the investigation on the miniature LHP (mLHP) for thermal control of electronic devices with heat dissipation capacity of up to 70 W have been discussed. Copper mLHP with disk-shaped flat evaporator 30 mm in diameter and 10 mm thickness was developed. Flat evaporators are easy to attach to the heat source without any need of cylinder-plane-reducer saddle that creates additional thermal resistance in the case of cylindrical evaporators. Wick structure made from sintered nickel powder with pore size of 3–5 μm was able to provide adequate capillary forces for the continuos circulation of the working fluid, and successfully transport heat load at the required distance of 60 mm. Heat was transferred using 3 mm ID copper tube with vapour and liquid lines of 60 mm and 200 mm length respectively. mLHP showed very reliable start up at different heat loads and was able to achieve steady state without any symptoms of wick dry-out. Tests were conducted on the mLHP with evaporator and condenser at the same level. Total thermal resistance, R total of the mLHP came out to be in the range of 1–4°C/W. It is concluded from the outcomes of the investigation that mLHP with flat evaporator can be effectively used for the thermal control of the electronic equipments with restricted space and high heat flux chipsets.

scholarly journals Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Patrik Nemec ◽  
Martin Smitka ◽  
Milan Malcho
Keyword(s):  
Grain Size ◽  
Heat Pipe ◽  
Nickel Powder ◽  
Heat Removal ◽  
Bipolar Transistor ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Porous Structures ◽  
Porous Wick ◽  
Wick Structure

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements’ influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made.

scholarly journals Fracture of three-dimensional lattices manufactured by selective laser melting

2019 ◽  
Vol 180-181 ◽  
pp. 147-159 ◽  
Author(s):  
Huaiyuan Gu ◽  
Sheng Li ◽  
Martyn Pavier ◽  
Moataz M. Attallah ◽  
Charilaos Paraskevoulakos ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Three Dimensional ◽  
Laser Melting
Sign in / Sign up

Export Citation Format

Share Document