Heat Transfer Simulation for the Welding of the T-Section

Boundary Conditions This model was run with a Gaussian heat flux distribution for the weld zone as used in other studies. The weld heat transfer model used is a combination of rapid heat flux followed with constant (melt) temperature imposed at the weld zone as verified by experiments.

Boundary Conditions (cont’d) The heat transfer coefficients on all surfaces were calculated using the vertical and horizontal plate correlations available in literature. Radiation boundary condition was applied where temperature was high.

T- Section: Stainless Steel Gap: Glass Cladding: Pure Copper Outer Insl: Kapton Inner Insl: Kapton+Glass Conductors: Pure Copper

All Dimensions are in inches. All temperatures are in Kelvin, except the graphical presentation of temperature with time where Celsius is used for easier comparison with other (experimental) results.

Gaussian heat flux imposed at the weld zone 0 < time < 0.01 secs

Addition of heat flux

Constant temperature imposed at the weld zone 0.01 < time < 1.5 secs

Constant Temperature

Natural Cooling with Convection and Radiation 1.5 < time < 60 secs

Natural Cooling

Next few slides show temperature profile at these specific locations 1-2Glass+Kapton 2-3Kapton 3-4Cu cladding 4-5Glass 6Highest temp point during welding

Conclusions The temperatures reached in this model are higher than in the two test cases because the thickness of steel sheet used here is 0.04” compared to the 0.06” used earlier. The temperature results here (2D) are higher (at least by 15% based on experiments) when compared with a 3D model. The maximum temperature at the edge of glass insulation observed here is 750 °C. The lower estimate for the melting of fiberglass is 820 °C.