Determinaton of the thermal boundary conditions during aluminum DC casting from experimental data using inverse modeling

摘要

Thermal boundary conditions applicable to the stationary part of DC casting have been determined using a laboratory set-up and 2D inverse modeling techniques.The influence of (non casting) parameters on the accuracy of the results is clarified,and the influence of casting related parameters,such as casting speed,water flow rate,temperature,surface structure and type of waterfilm generator on the thermal boundary condition has been examined.This investigation shows that the classical description of a heat transfer coefficient or heat flux as a function of surface temperature alone does not accurately describe the thermal boundary condition typical for DC casting.To account for the effect of impingement and re-heating of the surface in thedownstream area,the heat flux as a function of the distance from the impingement point should also be considered.The results show that the effect of the casting speed is mainly expressed in the pre-impingement and impingemnet zone,whereas the effect of cooling water flow rate is principally expressed in the downstream area.