Study On The Variation Characteristics Of Coolant Temperature Field During High Speed Cutting

In the modern high-precision machinery manufacturing,the position accuracy and fit accuracy of Mechanical Elements are affected by the temperature change,thus the reliability of the product was reduced greatly in the unstable temperature.The thermal error is mainly caused by the high temperature rise of the tool parts.The temperature of cutting tool exceeding the normal standard will make hot deformation to mechanical parts,so that the thermal deformation has a great influence on the mechanical precision.Especially in precision machining and large processing,the error caused by thermal deformation has a large proportion in the cutting process.For example,in the manufacturing process of the aero engine's whole turbine disk,the control for high-speed cutting tool temperature has a more stringent requirement.The cutting tool temperature was rose with the cutting process and the work piece surface was denatured at high cutting temperature.This phenomenon has serious influence on the performance of turbine disks.Therefore,in order to improve the cutting efficiency as well as the accuracy of the work piece and extend the tool life,it is necessary to reduce the friction during the cutting process and take away the heat produced by the deformation of the cutting area in time.The application of coolant is an effective means to reduce the cutting temperature.At the same time,applying coolant can reduce the work piece surface roughness and extend the tool life.By consulting a large amount of data and literature,the choice of coolant type and the choice of dosage for high-speed cutting are usually based on experience.The theory of heat transfer and heat transfer of cooling liquid in high speed cutting process is deficient.This situation will cause waste of resources,while increasing the environmental load.Thus,the study of high-speed cutting tool heat transfer model has far-reaching significance.In the current study,scholars mainly studied the characteristics of the tool surface temperature during the cutting process.However,the cooling and heat transfer characteristics of the cooling fluid were ignored during the cutting process in their study.In this paper,the heat transfer model of coolant fluid during high-speed cutting is studied in detail.The main contents are as follows:First of all,the convective heat transfer theory of incompressible liquid fluid is studied and the fluid boundary layer theory is applied in this paper.By analyzed the motion state of the coolant around the cutting tool,a two-dimensional heat transfer model of the coolant fluid is proposed in this paper based on the fluid boundary layer theory.Secondly,the flow function is introduced to change the parameters of the heat transfer model.The heat transfer model of coolant fluid was solved.The Taylor series expansion is used to obtain the expression of the coolant temperature gradient.The boundary condition of the model is determined by analyzing the coolant jet velocity(the external flow velocity of the fluid).The Numerical Solution of Temperature Gradient is solved by Brasius Method.The expression of Nu number is obtained by analyze heat transfer model.The heat transfer characteristics of the coolant fluid during high-speed cutting can be analyzed by the obtained formulas and numerical solutions.Finally,The simulation analysis of the numerical solution is obtained by Matlab simulation software.The cooling fluid temperature gradient is obtained.At the same time,the numerical solution proposed in this paper is compared with the experimental solutions of other scholars to verify the reliability of the heat transfer model built in this paper.