Learning Forum

[Jian Liu]

I'M SIMULATING LASER MELTING IN FLUENT USING SOLIDIFICATION/MELTING AND VOF. There is an inert gas atmosphere above the solid matrix. Now, the laser energy is a Gaussian energy surface heat source, which I have converted to a volumetric heat source.The following problems occur during laser action:

1.The density, thermal conductivity and specific heat capacity parameters of the set material are set to fixed values (divided into two types: before and after the melting temperature, and the paste zone is a piecewise-linear curve), and the melting point is set to 1690K, but why does the velocity vector appear at 1580K? As shown in the figure below, the volume fraction equivalent surface of the solid phase is selected as 0.5.

Any help is much appreciated.Thank you very much!

 

[Rob]

What is stopping the liquid phase moving before it's reached the melting temperature? Is the gas phase moving?

[Jian Liu]

Thank you very much for visiting!

1.To be precise, the air domain is mobile. Above is the gas action area, below is the molten matrix, and the laser acts between the two phases.

2.VOF and melt solidification models were used in the simulation.The density, thermal conductivity and specific heat capacity parameters of the set material are set to fixed values (divided into two types: before and after the melting temperature, and the paste zone is a piecewise-linear curve)，and the base material only sets the viscosity of the melted fluid.

Is it possible to stop the liquid phase moving by setting the melting point value and the viscosity of the melted fluid?

Thank you very much for your help！

[Rob]

How are you modelling the gas density? The motion could be a numerical effect, how is the convergence looking, and does the density change at all in the glass as it reaches those temperatures?

[Jian Liu]

Thank you very much!

 1.In this way, the density of the gas phase is set to a fixed value.

 2.I put the convergence curve of all aspects below, thank you!

[Rob]

Momentum isn't looking great, but hard to tell from the plot. If you replot with node values off how does it look?