NUMERICAL STUDY OF EFFECT OF FLANK WEAR ON HEAT TRANSFER ABILITY IN HIGH-SPEED ULTRASONIC VIBRATION CUTTING INTERFACES

High-speed ultrasonic vibration cutting shown great advantages by cutting temperature reduction due to periodic opened cutting interfaces for direct heat convection with coolants. To figure out accurate heat transfer ability, a 2-dimensional simplified model was developed and computational fluid dynamics (CFD) was used to calculate heat flux and Nusselt number. Three flank wear lengths for initial, initial-stable transition and stable stages were chosen and comparisons made between CFD results and wear progresses indicated that heat transfer ability demonstrated better performance during the stable wear stage at low cutting speed. As cutting speed increased the effect of ultrasonic vibration was weakened.