A. Javidi Shirvan, M. Sass-Tisovskaya, I. Choquet, University West, Trollhättan, Sweden
Heat transfer during arc welding can significantly affect the shape microstructure and the mechanical properties of a weld. A better knowledge of the heat transferred to the weld pool is thus an important issue, that can be partly addressed via arc simulation. Simulation results can then be used as input for weld pool modeling, optimization and calibration of arc parameters, or for demonstrating physical arc behavior.
This study aims evaluating and comparing the ability of two software to model a plasma arc: Fluent 6.2 (Lebanon, NH, USA) and OpenFOAM 1.4 (http://www.openfoam.org). The well documented Tungsten Inert Gas (TIG) welding test case of [1] was retained. The anode is a water cooled copper plate so that it does not melt, and a stationary axisymmetric arc can be established.
The Lorentz force is a driven force of this application. For axisymmetric arcs its calculation can be done using either the magnetic induction or the electric potential equation. Both have been tested in Fluent, and some difficulties were met since the imposed frame for adding transport equations does not fit the magnetic induction boundary conditions for instance.
Models for transport and thermal coefficients valid for an Argon plasma, also the Lorentz force and the resultant Joule heating, were implemented in OpenFOAM (characterized by a fully accessible source). The two approaches previously mentioned are also being tested using OpenFOAM.
The simulation results obtained with Fluent, OpenFOAM, and existing experimental data [2] will be compared. Advantages and drawbacks of these software will be discussed.
References
1. M.C. TsaiI, Sindo Kou, Heat transfer and fluid flow in welding arcs produced by sharpened and flat electrodes, Int. J. Heat Mass Transfer, Vol. 33, No. 10, pp 2089-2098, (1990).
2. G..N. Haddad, A.J.D Farmer, Temperature measurements in gas tungsten arcs, Welding Journal, Vol. 64, pp. 339-342s, (1985).
Summary: This study aims evaluating and comparing the ability of the two following software to model a plasma arc: Fluent 6.2 and OpenFOAM 1.4. The investigated test case is a well documented (both numerically and experimentally) Tungsten inert gas arc welding application where the arc can be assumed stationary and axisymmetric.
