Optimization of Rib Installation Conditions for Promoting Air Exhaust from Backward Step Part by Visualization Experiments of Water Flow

Abstract

  In order to investigate the flow of molten metal in the cavity of a die, experimental simulation was carried out using a water flow model. The experimental cavity has a backward step configuration at the test zone, where the flow behavior and air exhaust process were investigated. The rib material was installed at the step to study its effects on air exhaust for various Reynolds numbers (flow velocities) and rib installation conditions. The main results obtained are as follows. The flow behavior in the cavity with rib can be classified into two patterns. This classification is mainly influenced by the thickness of the rib, and hardly influenced by the Reynolds number (flow velocities) and rib position. The best conditions for the rib thickness and position achieved air exhaust in a short time with little air remaining inside. Increasing the Reynolds number (flow velocities) is effective for suppressing casting defects due to the entrainment of air.