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en:grundlagenhandbuch:aufschmelzberechnung:modifiziertes_disperses_aufschmelzen [2026/02/05 11:05] – [Modified Disperse Melting Model] pkaen:grundlagenhandbuch:aufschmelzberechnung:modifiziertes_disperses_aufschmelzen [2026/02/05 11:10] (aktuell) – [Particles' Influence on the Flow] pka
Zeile 15: Zeile 15:
 The correction factor is valid in the range 0,2 < d/h <0,9 and is based on an approximation of the dimensionless temperature field. It shows a good match with the CFD results, and compares the middle temperature gradient at the particle surface with finite channel height to the middle temperature gradient with infinite expansion. The correction factor is valid in the range 0,2 < d/h <0,9 and is based on an approximation of the dimensionless temperature field. It shows a good match with the CFD results, and compares the middle temperature gradient at the particle surface with finite channel height to the middle temperature gradient with infinite expansion.
  
-An analytical solution of the energetic differential equation is in this case hard to derive [Pape06].+An analytical solution of the energetic differential equation is in this case hard to derive [[en:grundlagenhandbuch:aufschmelzberechnung:literatur|[Pape06]]].
  
 The factor $f_{lh}$ does not include a consideration of the expansion in channel width direction. In this case numerics are also used because an analytical derivation does not seem possible. The simulations show that the influence of the channel width only occurs with low pitch-screw diameter-ratios. But these are rarely used in practice. A correction for the heat flow with reference to the finite channel width is therefore neglected. The factor $f_{lh}$ does not include a consideration of the expansion in channel width direction. In this case numerics are also used because an analytical derivation does not seem possible. The simulations show that the influence of the channel width only occurs with low pitch-screw diameter-ratios. But these are rarely used in practice. A correction for the heat flow with reference to the finite channel width is therefore neglected.
Zeile 47: Zeile 47:
 The melting process can not be considered without taking into account the whole process. Interactions between single particles as well as the particle dimension have an influence on the viscosity of the melt-solid mixture. The melting process can not be considered without taking into account the whole process. Interactions between single particles as well as the particle dimension have an influence on the viscosity of the melt-solid mixture.
  
-According to Potente and Melisch [Meli98, Pote96] the interactions are considered by using an effective channel height and width which is dependent on the amount of solid. As shown in the illustration below the melt-solid mixture is considered independent of each component. In this way the flow can be modelled through the melt above the solid layer.+According to Potente and Melisch [[en:grundlagenhandbuch:aufschmelzberechnung:literatur|[Meli98, Pote96]]] the interactions are considered by using an effective channel height and width which is dependent on the amount of solid. As shown in the illustration below the melt-solid mixture is considered independent of each component. In this way the flow can be modelled through the melt above the solid layer.
  
 {{ :en:grundlagenhandbuch:aufschmelzberechnung:en_sigma150_dlg_grundlagenhandbuch_aufschmelzberechnung_012.svg?700%nolink |}} {{ :en:grundlagenhandbuch:aufschmelzberechnung:en_sigma150_dlg_grundlagenhandbuch_aufschmelzberechnung_012.svg?700%nolink |}}
  
-**Figure:** Consideration of the solid particle amount in the original disperse melting model [Thüm08]+**Figure:** Consideration of the solid particle amount in the original disperse melting model [[en:grundlagenhandbuch:aufschmelzberechnung:literatur|[Thüm08]]]
  
 In the modified melting model the flow in the melt-solid mixture is formed with the help of an adjustment of the viscosity. For this purpose the correction of the power law consistency with the factor $f_Φ$ is in introduced. In the modified melting model the flow in the melt-solid mixture is formed with the help of an adjustment of the viscosity. For this purpose the correction of the power law consistency with the factor $f_Φ$ is in introduced.
Zeile 67: Zeile 67:
 $$f_\phi = 1 + \frac{5}{2}\left(\frac{\phi_{M,s}}{\phi_{M,s} + \frac{\rho_s}{\rho_m}(1 - \phi_{M,s})}\right)\phi_{V,s} + \frac{141}{10}\left(\frac{\phi_{M,s}}{\phi_{M,s} + \frac{\rho_s}{\rho_m}(1 - \phi_{M,s})}\right)^2$$ $$f_\phi = 1 + \frac{5}{2}\left(\frac{\phi_{M,s}}{\phi_{M,s} + \frac{\rho_s}{\rho_m}(1 - \phi_{M,s})}\right)\phi_{V,s} + \frac{141}{10}\left(\frac{\phi_{M,s}}{\phi_{M,s} + \frac{\rho_s}{\rho_m}(1 - \phi_{M,s})}\right)^2$$
  
-If the $d_p/h$-ratio approaches 1 the particle diameter considered corresponds approximately to the channel height, and the influence of the particle size on the flow has to be considered. Following Pape [Pap06] another correction of the power law consistency is introduced.+If the $d_p/h$-ratio approaches 1 the particle diameter considered corresponds approximately to the channel height, and the influence of the particle size on the flow has to be considered. Following Pape [[en:grundlagenhandbuch:aufschmelzberechnung:literatur|[Pape06]]] another correction of the power law consistency is introduced.
  
 $$K_{sm} = K \cdot f_\phi \cdot f_{dh}$$ $$K_{sm} = K \cdot f_\phi \cdot f_{dh}$$