Numerical Simulation of Transient Multiphase Field During Hybrid Plasma-Laser Deposition Manufacturing

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Fanrong Kong ◽  
Haiou Zhang ◽  
Guilan Wang

The hybrid plasma-laser deposition manufacturing (PLDM) process is developed based on the plasma deposition manufacturing (PDM) technology. PLDM belongs to the three-dimensional (3D) welding technology and involves the laser power as an augmented heat resource. Compared to PDM technology, the PLDM process has many advantages such as a higher power density, higher processing precision, refined microstructure, and improved mechanical performance of forming components. There exist complicated physical and metallurgical interaction mechanisms due to the combination of PLDM along with the rapid melting and solidification process. Moreover, the interaction between the laser and plasma arc also directly influences the forming quality and precision of the 3D metal components. Therefore, the proposed work is a preliminary attempt to study the transport phenomena in the PLDM process, in which the heat transfer, fluid flow, and molten powder depositing processes have been investigated in detail. The numerical study is performed by using a pressure-based finite volume difference technique after making appropriate modifications of the algorithm. The associated solid/liquid phase transformation process is involved by using an enthalpy-porosity method, and the level-set approach is introduced to track the evolution of weld surface of the deposition layer with powder feeding. An experimentally based hybrid heat input model is developed to involve the influence of the interaction of laser and arc plasma on the redistributed energy absorption by the material. Corresponding experiments of the PLDM process are performed using the same parameters as in the computations, showing a good qualitative agreement.

2010 ◽  
Vol 97-101 ◽  
pp. 3828-3831 ◽  
Author(s):  
Ying Ping Qian ◽  
Ju Hua Huang ◽  
Hai Ou Zhang

The present study is a continuation of the previous research on direct metal part fabrication with hybrid plasma-laser deposition manufacturing (PLDM). It is remarkably important for manufacturing high accurate part to investigate the factors influencing the precision of deposited layer and obtain the influence rules. Many factors perhaps affect the layer precision, such as average power of laser, repetition frequency, pulse width, hybrid angle between laser beam and plasma beam, speed of powder feed, deposition speed, and amount of feed along Z direction and so on. In this paper, the factors except laser parameters published in other paper were researched experimentally. The results were concluded as follows: (1) The width of the layer increases and the thickness decreases with the increasing of hybrid angle. (2) The depth of layer increases with the increasing of the amount of powder feed but the width of layer is nearly unchanged. (3) The width and thickness of layer reduces with the increasing of deposition speed. (4) The deviation between the amount of feed along Z direction and the depth of depositing layer makes the part precision decrease.


Author(s):  
Ramesh Narayanaswamy ◽  
Tilak T. Chandratilleke ◽  
Andrew J. L. Foong

Efficient cooling techniques are one of the critical design requirements for maintaining reliable operational characteristics of modern, miniaturised high performance electronic components. Microchannel heat sinks form an integral part of most devices used for thermal management in electronic equipment cooling. A microchannel of square cross section, having internal longitudinal fins is considered for analysis. A numerical study is carried out to investigate the fluid flow and heat transfer characteristics. Three-dimensional numerical simulations are performed on the microchannel in the presence of a hydrodynamically developed, thermally developing laminar flow. Further on, a thermodynamic analysis is carried out, for a range of fin heights and thermophysical parameters, in order to obtain the irreversibilities due to heat transfer and fluid flow within the microchannel. An optimum fin height, corresponding to the thermodynamically optimum conditions that minimize the entropy generation rates has been obtained. The effect of the presence of internal fins on the entropy generated due to heat transfer, fluid friction, and the total entropy generation is also provided.


Author(s):  
Alexander P. Skuratov ◽  
Alexander V. Ivlev ◽  
Artem A. Pianykh

A three-dimensional mathematical model of the solidification process of a liquid metal is considered, taking into account the mobility of the boundaries at which the phase transition is carried out (Stefan boundary value problem). The algorithm of calculation is improved, allowing due to the use of the Dirac δ-function in determining the effective heat capacity to take into account the nonlinearity of the equation of unsteady thermal conductivity and the heat of the phase transition. A numerical study of heat transfer during solidification of lead-containing aluminum melt droplets in air and water is carried out. The influence of droplet size and melt overheating on the solidification dynamics of granules has been studied. An approximate ratio based on the square root law is proposed, taking into account the amount of overheating of the liquid phase and linking the thickness of the formed solid phase with the duration of the granulation process


Author(s):  
Byung-Jae Kim ◽  
Hyeon-Seok Seo ◽  
Won-Ho Lee ◽  
Jong-Hyun Ahn ◽  
Youn-Jea Kim

Author(s):  
C. Abegg ◽  
Graham de Vahl Davis ◽  
W.J. Hiller ◽  
St. Koch ◽  
Tomasz A. Kowalewski ◽  
...  

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.


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