*LENS
r1, r2, [r3]
r1: r*8: sphere radius. Default 0.d0
r2: r*8: local convection. Default 0.d0
r3: r*8: time gas is turned off. Default 1.d50
This card applies an additional component to the applied convection specified by *CONV in thermal analyses. This is used to simulate the forced convection due to the forced gas flows in the LENS® process or similar Laser-based Directed Energy Deposition machines.
Reference: JC Heigel, P Michaleris, and EW Reutzel. "Thermo-mechanical model development and validation of directed energy deposition additive manufacturing of ti-6al-4v." Additive Manufacturing, 2014.
*LENS models the region of forced convection as a sphere whose center is co-located with the center of the simulated heat source as controlled by *LSRF, of a radius r1 in mm, of a value r2 in W/mm2, which is cut off at time r3 in seconds.
A custom distribution of the forced convection can be programmed through the lensconvS subroutine in the user.f file.