Simulation Test Of Gundrill Structure Optimization Based On CFD

In advanced production fields such as the aerospace industry,nickel-based superalloy materials are mainly used to manufacture key components such as turbine disks,blades and combustion chambers.However,the poor machinability and thermal conductivity of nickelbased superalloy materials make it difficult to ensure the machining quality of deep small holes because of the high cutting temperature and difficult chip evacuation during the machining process,so it is very important to improve the quality of deep small holes machined on nickelbased superalloy materials.Firstly,this paper analyzes the structure of gundrill for the problems of high cutting temperature and difficult chip evacuation when machining on nickel-based superalloy materials,establishes a mathematical model of the drill,carries out different theoretical analyses on the basis of computational fluid dynamics,and establishes a heat transfer model during machining and an energy loss model during the flow of cutting fluid.Secondly,based on the four factors of the coolant hole position and diameter,the shoulder dub-off angle and the cutting fluid supply rate of the small diameter deep-hole gundrilling bit,the three-dimensional models of many different structures of drill bits and fluid domains were established,and multi-variate orthogonal simulation experiment were designed with CFD simulation software to study the cooling and chip evacuation effect of cutting fluid during the drilling process.Numerical simulation is used to quantify the cooling and chip removal of the cutting fluid,and then the temperature distribution law of the inner and outer edge and the change of the pressure and velocity of the cutting fluid in the bottom space of the conveying channel are analyzed.Finally,the structural parameters and technological parameters of the gundrill for processing small diameter deep holes are optimized according to the test results,and the shoulder dub-off angle and cutting fluid supply pressure are selected as variable factors for machining experiments according to the actual machining conditions.The inner wall quality of the processed holes is used as a reference to analyze and verify the results of some simulation experiments.According to the analysis of the simulation test results,it can be seen that the structure configuration of the coolant hole and the cutting fluid supply rate have a greater impact on the cooling and chip removal effect in the machining.Within the parameter range,the optimal horizontal scheme with 38° hole location,large diameter coolant hole combined with 5°shoulder dub-off angle and 19m/s inlet speed is selected,which has better cooling and chip removal effect.In the actual machining experiment,within a certain parameter range,smaller shoulder dub-off angle and higher cutting fluid input pressure can get better machining effect,more conducive to improving the machining quality of the hole.