Development of thermo-fluid simulation technique for extruder and chamber of FDM-type 3D printer for printing high-melting-point materials

In this study, for the deposition of high-melting point engineering plastics (PEEK, ULTEM), a thermo-fluid simulation method for a 3D printer nozzle and chamber was developed based on computational fluid dynamics techniques. To predict the temperature distribution of the extruder, surface-to-surface radiative heat transfer and laminar natural convection models were used. The developed method was applied to the thermal analysis of the sample nozzle configuration, and less than 5% error compared with the test result was observed. For the chamber thermal simulation, the pressure drop and heat transfer effect of the positive thermal coefficient heater were modeled based on a porous medium. In addition, the user-defined function provided by ANSYS Fluent was used to model the duct connecting the chamber and the positive thermal coefficient heater to increase the simulation efficiency. The results were compared with those of the model chamber test, and it was showed that the uniformity of the air temperature in the chamber could be predicted with an error of less than 4%. The numerical simulation method developed in this study can accurately predict the thermo-fluid field of the nozzle and chamber. The proposed method is useful in the development of a 3D printer for printing high-melting-point engineering plastics.