D.H. Lammlein PhD Dissertation - Vanderbilt University

Figure 162: A closeup view of mesh refinement on the tool face. The featured shoulder
and threaded probe can be seen. The mesh was finest at the interface.
The implicit formulation was used in Fluent with the laminar viscosity setting.
The Presto pressure solver for highly rotating flows was selected due to the relatively
high rotation rate with respect to traverse rate. The weld material viscosity function was
set by user-defined function and defined using the Carreau viscosity model:
1 exp
where µ ∞ is the infinite shear viscosity, µ 0 is the zero shear viscosity, is the local shear
strain-rate, λ is the time constant, T 0 is the reference temperature, T is the local
temperature, and n is the power law index. In the weld zone (see Figure 161), Carreau
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