Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- en:berechnungen:leistung_und_schubspannungen [2024/07/21 14:41] – neelest
+++ en:berechnungen:leistung_und_schubspannungen [2026/09/17 12:46] (aktuell) – gelöscht - Externe Bearbeitung (Unbekanntes Datum) 127.0.0.1
@@ Zeile 1: / Zeile 1: @@
-======Power and wall shear stress======
-FIXME
-===== Power and wall shear stress =====
-The same conditions have to be filled for the calculation of the power and wall shear
-stress as for the calculation of the melting profile.
-**Realization of the theoretical principles**
-In the power calculation a distinction is drawn between the incipient fusing and the
-melting section. In the incipient fusing section, i. e. from the start of the first heating
-section through to the point of melt pool formation, the power can be established via
-an average melt layer thickness, assuming a pure drag flow in the melt film. The
-power conversion in the pure solids section between the hopper and the first heating
-section is neglected, since no pressure has built up till then and the frictional forces of
-the solids at the barrel wall are negligibly small compared to the frictional forces of
-the melt film.
-The calculation for the other sections results in an addition of the wall shear stresses
-at the barrel. Similar to the calculation of the pressure throughput approximation
-equations are used, which are based on numeric examinations. A distinction is drawn
-between the melting section, where high wall shear stresses in the melt film occur
-and the pure melt conveying.
-The overall drive power required (without transmission losses) and the overall torque
-is calculated from the local power requirement.
-The heating/cooling power consists of components from the melt film and the melt
-pool. The temperature gradient at the barrel wall is established for both sections and
-from this the necessary heating/cooling power is determined via a temperature
-balance. The power at each single calculation point is added up for the heating
-section in question. The heating/cooling power calculation only allows for the heating
-flow between the band heater and the melt, but not for any heat losses (of any type)
-towards the outside.