水モデルダイカスト実験と数値解析の比較による気泡追跡

抄録

  Casting CAE is used practically to predict casting defects and in the casting design of the ingate system. However, the prediction accuracy of defects caused by flow dynamics such as air and gas entrainments, miss run, oxide film, etc. is not sufficient. So, it is important to analyze the mechanism of air entrainment and gas generation and accurately predict how the gas moves.

  In the present study, we observed air bubbles moving during the mold filling of die casting using a water model experimental apparatus and tried to simulate the bubble behavior using the marker function of the casting CAE software. The results using the marker function could not estimate the experimental ones accurately. For this reason, bubble tracking experiments using a circulating water tank was conducted and the governing equation for air movement with the virtual mass term was established. The results of calculating air movement using the modified air movement equation were almost the same as the experimental ones during mold filling in die casting experiments using the water model, providing some information on the forces acting on the bubbles moving in the fluid.