2.4 Physical Properties and Calculation Parameters
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Fig. 2.8 Temperature field numerical simulation grid for deep penetration laser welding process
Table 2.1 shows the basic parameters of the heat source model during simulation
of the keyhole and weld pool in the process of deep penetration laser welding.
2.5 Effect of Welding Speed on Keyhole Profile
2.5.1 Temperature Distribution in Deep Penetration Laser
Welding of Titanium Alloys
2.5.1.1 Computational Hypothesis
(1) The free surface of weld pool is flat.
(2) The weld pool fluid is incompressible Newtonian fluid.
(3) The flow pattern of molten metal is laminar flow.
(4) Buoyancy calculation is based on the Businesk hypothesis.
(5) The node above the material boiling point is regarded as the gasification equivalent point, and the region above the boiling point is regarded as the gasification
evaporation zone. The material gasified can be keyhole in the weld pools.
(6) Quasi-steady state condition is met.
(7) The influence of the upper and lower surface airflow on the temperature field
is not considered.