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en:grundlagenhandbuch:aufschmelzberechnung:2d_disperses_aufschmelzen [2025/06/16 12:48] – deppe2en:grundlagenhandbuch:aufschmelzberechnung:2d_disperses_aufschmelzen [2026/01/28 21:21] (aktuell) – neelest
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 ====== 2D disperse melting model ====== ====== 2D disperse melting model ======
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-===== 2D disperse melting model ===== 
  
 Since SIGMA 11.1, a new melting model is available - the 2D disperse melting model. The naming is based on the two-dimensional particle temperature analysis - from the feeding zone through the solid-conveying-zone into the melting zone, the temperatures of the particles are calculated along the particle radius and along the screw length. Since SIGMA 11.1, a new melting model is available - the 2D disperse melting model. The naming is based on the two-dimensional particle temperature analysis - from the feeding zone through the solid-conveying-zone into the melting zone, the temperatures of the particles are calculated along the particle radius and along the screw length.
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 The energy input by deformation decreases, the higher the temperature of the material immediately before the deformation is. In addition, with increasing melt content and concomitant increase in the degree of filling, the heat conduction from the melt dominates the particle temperature development. It is no longer negligible. The melting of the spherical particles in the surrounding melt is well imaged by the modified disperse melting model. Therefore, this model is used when the energy input due to deformation becomes negligible. The energy input by deformation decreases, the higher the temperature of the material immediately before the deformation is. In addition, with increasing melt content and concomitant increase in the degree of filling, the heat conduction from the melt dominates the particle temperature development. It is no longer negligible. The melting of the spherical particles in the surrounding melt is well imaged by the modified disperse melting model. Therefore, this model is used when the energy input due to deformation becomes negligible.
  
-The filling degree of the components melt and solid is the decisive criterion for going on with the calculation according to the modified disperse melting model. In this model, the spherical particles in the screw channel after the "deformation zone" are almost closely spaced packed. It is model assumption the disperse melting starts when the voids between the spheres are filled with melt. The packing density of a densest packing is π/(3√2)~0,74048=74,048 %, which means that the free volume occupies 25.952 %. As soon as the degree of molten material exceeds the melt rate of 25.952 %, the subsequent melting is calculated by the modified disperse melting model. This modeling takes into account the melting by a successive reduction of the radius due to convective heating in a finite channel geometry.+The filling degree of the components melt and solid is the decisive criterion for going on with the calculation according to the modified disperse melting model. In this model, the spherical particles in the screw channel after the "deformation zone" are almost closely spaced packed. It is model assumption the disperse melting starts when the voids between the spheres are filled with melt. The packing density of a densest packing is  
 + 
 +$$\frac{\pi}{3\sqrt{2}} \sim 0,74048 = 74,048$$ 
 + 
 +which means that the free volume occupies 25.952 %. As soon as the degree of molten material exceeds the melt rate of 25.952 %, the subsequent melting is calculated by the modified disperse melting model. This modeling takes into account the melting by a successive reduction of the radius due to convective heating in a finite channel geometry.