Comparison of flow behaviour in pressurized gating systems using water models and numerical simulation

Purpose The purpose of this work is to visualize the flow behaviour in critical sections of a pressurized gating system. Design/methodology/approach The investigation was carried out using water models of gating system that were designed, invoking the principles of similitude. Water was used as the filling medium, and the manner of flow through various sections of the gating system and the cavity was recorded with a high-speed camera capable of capturing images up to 10,000 frames per second. This was followed by an analysis of the results obtained from each phase. Finally, computer simulations of flow were carried out using commercial software. The manner of filling as observed during experiments and that during simulation were compared so as to draw some useful conclusions on the utility of flow visualization using water models and the capability of software to predict the filling pattern during casting process. It was understood that water models are powerful aids for understanding the intricacies of flow through critical sections of the gating systems. Findings It was observed that water models are a reliable indicator of the mould-filling process. Further, substantial differences in the filling pattern were observed between water model experiments and filling simulation using commercial software. Research limitations/implications The findings are limited to horizontal plate-type castings. Also, the influence of surface roughness in the flow through the runner is not considered. Originality/value This work facilitates understanding of the importance of flow visualization on the quality and reliability of castings.