Es erkennt hier eine sprudelnde Quelle. Wir auch. - ULV Leoben ...
Es erkennt hier eine sprudelnde Quelle. Wir auch. - ULV Leoben ...
Es erkennt hier eine sprudelnde Quelle. Wir auch. - ULV Leoben ...
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32<br />
This two part casting presents a unique challenge in coupling fluid dynamics of<br />
a filling process with remelting of a pre-cast cylinder of a double-poured dual<br />
alloy casting.<br />
Fig. 1: Flow patterns during casting.<br />
Simulation of a Dual Alloy Casting<br />
The molten bulk material is poured into the the precast<br />
cylinder and the upper and lower molds, filling ends at<br />
120s. Due to the pouring stream impact during filling, a<br />
well-mixed zone exists to a depth approx 1 m below the<br />
molten metal surface and is characterized by velocities on<br />
the order of 0.1 to 1 m/s as shown in Fig. 1. Below the<br />
well-mixed zone the flow is quiescent with relatively low<br />
velocities less than 50 mm/s. Further analysis showing the<br />
evolution of melting (shell thickness), liquid velocity, temperature,<br />
and maximum effective thermal conductivity at<br />
three points are shown in Fig. 2. The correlation of these<br />
phenomena confirm the hypothesis that melting of the<br />
cylinder occurs only during contact with the the turbulent<br />
well-mixed zone of the bulk material.<br />
Autumn Fjeld<br />
Lehrstuhl für Modellierung und Simulation<br />
metallurgischer Prozesse<br />
an der MUL seit: 2006<br />
Email: autumn.fjeld@unileoben.ac.at<br />
www.smmp.at.hm<br />
Zur Person:<br />
Post Doctoral Research,<br />
seit 2006: am Lehrstuhl für Modellierung und Simulation<br />
metallurgischer Prozesse<br />
The objective of this module is the analysis of filling induced<br />
flow phenomena and prediction of melting in a two-part casting.<br />
The bulk material (cast iron) is poured from above into a moldcylinder<br />
assembly; the cylinder is a large precast tube of highly<br />
alloyed steel assembled between upper and lower molds. The<br />
durability of these castings is dependent upon optimum cylinder<br />
re-melting: sufficient melting must occur for good bulk-cylinder<br />
bonding, however an excess of melting results in contamination<br />
of the bulk material from the highly alloyed cylinder. The interaction<br />
of the turbulent bulk liquid and the melting of the cylinder<br />
material has not been well understood by the industry partner,<br />
providing an opportunity for the development of a numerical<br />
model to analyze flow and melting phenomena.<br />
Fig. 2: Evolution of cylinder melting during filling at three positions.<br />
Forschungsschwerpunkte:<br />
Casting Processes, Fluid Dynamics, Solidification and<br />
Melting