Computational Fluid Dynamic Modelling and Optimisation of Internal Twist-Drill Coolant Channel Flow

Due to the increasingly challenging thermal loads during drilling applications, coolant application is prevalent in twist-drill machining of metals. However, because the cutting zone is not directly observable, there is limited knowledge encompassing the distribution of coolant during the cutting process. This work looks to expand current knowledge of coolant delivery during the cutting process and inform future tool design through the application of numerical methods. This is implemented in the form of two numerical models: a through-tool model, which examines internal coolant flow and the second model which calculates coolant exit flow behaviour. The through-tool model employs a single phase model and is used to perform a parametric study which identifies the influence of each design parameter on the delivery of coolant. In addition to this metamodelling techniques are adopted to give a global overview of tool parameter effects on coolant delivery and to identify optimal channel configurations. The coolant exit flow model employs the Volume of Fluid method to simulate the multiphase exit flow of coolant and is validated against experimental data for a simplified case. This model was used to evaluate coolant exit flow for four different coolant channel configurations and study the influence of channel configuration parameters on domain flooding, surface wetting and flow field features.