基于 Level-Set 界面跟踪方法建立了激光熔覆过程的三维瞬态数值模型，研究了瞬态熔化和凝固过程中传热传质的演化规律。该模型使用 Level-Set 方法跟踪熔池气/液界面，采用焓－多孔度（enthalpy-porosity）方法得到了固/液界面之间的糊状区，并考虑了质量添加、材料熔化/凝固、热毛细效应（Marangoni效应）、浮力效应、活性元素质量传输等对熔池流动和界面的影响。通过该模型，具体分析了质量添加、力和界面平衡条件对熔池气/液界面的影响，以及由熔池温度/浓度分布引起的热毛细效应、金属材料的熔/凝过程和熔池流动形式对熔池固/液界面的影响。结果表明：熔池的气/液界面主要由力平衡条件决定，截面近似为圆弧型，其尺寸与单位时间的质量添加量相关。熔池的固/液形态由于熔池的表面温度梯度和表面活性元素含量共同引起的熔池流动方向和速度的变化，出现三种不同的类型，分别为下凹型（熔池内流） ...
On The Purification Of Waste Waters Using Multi-Bore Filters: Simulation Of A Long-Term Filtration Stage
Dipartimento di Matematica U. Dini, Universita' di Firenze, Italy
We present the progress of the simulation activity we are carrying out within the PURIFAST LIFE+ project. We first present the model we formulated to describe the macroscopic effects of the filtration process taking place in a multi-bore filter, focusing on the fouling phenomenon. In membrane-based filters the fouling phenomenon is the major reason of a decreasing filtration efficiency. ...
Eswaran M, P. Goyal, Anu Dutta, G.R. Reddy, R. K. Singh , K.K. Vaze
Bhabha Atomic Research Centre, Mumbai, India
A 2-D unsteady viscous flow around two cylinders is studied by numerical solutions of the unsteady Navier-Stokes equations with a finite element formulation using COMSOL Multiphysics®. The results of a numerical investigation of the Strouhal frequencies of two identical, stationary, parallel circular cylinders arranged in staggered configurations is presented in this paper. A simple two cylinder ...
MHD Electrolyte Flow within an Inter-electrode Gap Driven by a Sinusoidal Electric Field and Constant Magnetic Field
C. Bradley , J. Samuel ,
 Benét Laboratories, U.S. Army RDECOM-ARDEC, Watervliet, NY, USA
 Department of Mechanical Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA
PECM is a necessary extension to traditional ECM for some high-performance materials. Electrolyte flow in the inter-electrode gap (IEG) can be assisted using a magnetic field to allow higher currents, but this creates a magnetohydrodynamic flow. This paper presents a study of flow velocity in an IEG with a sinusoidal electric field within a magnetic field. EIS experiments use a 7075 aluminum ...
L. Graber, N.G. Suttell, D. Shah, D.G. Crook, C.H. Kim, J. Ordonez, S. Pamidi
Center for Advanced Power Systems, Florida State University, Tallahassee, FL, USA
Heat sinks for cryogenic applications using helium gas as the coolant are not readily available. They require to be designed specifically for the intended application. A finite element model was developed to study the feasibility and optimize the design. The FEM computing package COMSOL Multiphysics allowed to couple fluid flow and heat transfer as needed. An experiment was designed to validate ...
J. Martel, N. Elabbasi, D. Quinn, J. Bergstrom, M. Toner
BioMEMS Resource Center, Massachusetts General Hospital, Boston, MA, USA
Veryst Engineering, Needham, MA, USA
Inertial focusing is a promising microfluidic technique for separating and concentrating cells of interest, processes routinely utilized in many medical procedures. This phenomenon is characterized by suspended particles in a flow spontaneously migrating across streamlines to equilibrium positions within a channel cross-section. We developed CFD models in COMSOL Multiphysics® to predict the ...
E. Malcuit, A.L. Gille
CFG Services, Orléans, France
Within projects of geothermal energy, we need hydrodynamic and thermal modeling to forecast the impacts of geothermal deep wells on existing wells. In case of pumping and reinjection of the geothermal fluid in a deep groundwater reservoir, located in a sedimentary basin with lateral and vertical lithology variations and major faults, it is fundamental to understand the behaviour of the ...
K.Revathy, S. Agarwal, B. Muralidharan, G. Padmakumar, K. K. Rajan
Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
Electro refining is one of the important step in the Pyro processing nuclear spent fuel with molten salt. The electro refiner is a process vessel consists of anode ,cathodes and stirrers and ultra –high pure argon gas is provided at the top for inert atmosphere and at the bottom a cadmium layer is provided. The vapor pressure of the cadmium is high at the operating temperature, the cadmium vapor ...
V. S. P. Rajesh
St. Mary's Group of Institutions, Jawaharlal Nehru Technological University, Hyderabad, Telangana, India
Fluid and structure Interaction analysis can be applied to versatile fields of engineering applications, helps in understanding the affects of one material on other, thereby reducing the effect of physical parameters like nonlinear response, vibration in flow channel etc. Rapid development of technology led to the application of this Fluid-Structure Interaction (FSI) in Microfluidics based ...
S. Oukach, M. Elganaoui, B. Pateyron, and H. Hamdi
Laboratoire des Sciences des Procèdes Céramiques et de Traitements de Surface SPCTS, Limoges, France
Laboratoire de Mécanique des Fluides et Energétique LMFE, Marrakech, Morocco
The quality of coatings obtained by means of thermal spraying depends strongly on the mechanism of the interaction between the molten droplets and the surface to be covered. The aim of the present study is to simulate the impact of a droplet onto a substrate, in order to have a good understanding of the dynamics of droplets impact. In this study, the process of droplet spreading is described; ...