The predicted influence of turbulence in stationary gas tungsten arc welds
- Univ. of Waterloo, Ontario (Canada)
The effects of turbulence in stationary gas tungsten arc welds (GTAW) in AISI 304 stainless steel have been examined using a finite element thermofluids model of the process. It is capable of modelling either laminar or turbulent flow in the weld pool. The model includes buoyancy, Lorentz and Marangoni driven fluid flow, a large deformation model of the free surface, volumetric expansion and a {kappa}-{epsilon} turbulence model. To facilitate implementation of the wall function boundary conditions for the {kappa}-{epsilon} turbulence model, a dynamic numerical grid remapping technique was used to clearly separate elements in the liquid from those in the solid. The laminar and turbulent thermofluids models correctly predicted the qualitative influence of sulphur contents of AISI 304 stainless steels on Marangoni induced flow and weld pool dimensions previously observed in experiments; however, the laminar flow model consistently overpredicted the weld pool depths by more than 54%. Alternatively, all results predicted using the {kappa}-{epsilon} turbulence thermofluids model were found to be within the limits of experimental uncertainty reported for experimental measurements. This strongly suggests that the flow in these stationary GTA welds in AISI 304 stainless steel was turbulent and that accurate predictions of fluid flow patterns and weld pool shapes and dimensions in AISI 304 welds will only be possible if the effects of turbulence are modelled accurately.
- Sponsoring Organization:
- Natural Sciences and Engineering Research Council of Canada, Ottawa, ON (Canada)
- OSTI ID:
- 442964
- Report Number(s):
- CONF-950682--; ISBN 0-87170-567-2
- Country of Publication:
- United States
- Language:
- English
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