Influence of Surface Cooling on Extrudate Swell - a Numerical Study
نویسنده
چکیده
Influence of convective cooling at the extrudate’s free surfaces on its own swelling behaviour is examined numerically when viscous fluids of a Newtonian type are extruded. In circular die extrusion, increasing the surface heat transfer coefficient h increases extrudate’s thickness swell at low Nahme-Griffith number Na; at high Na, however, this trend tends to be reversed. With annular dies, a higher cooling rate also enhances thickness swell, but suppresses extrudate’s outward deflection. The influence of h on extrudate swells is stronger in extrusion situation with higher Péclet number.
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