Optimum design of a saw-tooth-shaped dental air-turbine using design of experiment

Air turbine high-speed handpieces have been used in dental cutting for more than 40 years. The air turbine is main part of the dental handpiece. High-pressure air enters the turbine and strikes the blades to drive the turbine rotor. The effects of the air-turbine blade configuration were investigated for the optimum air-turbine design by using ANSYS CFX. The objective of the research was to find an optimum design of the air-turbine blade configuration to increase the torque. Design of Experiments was used for the optimization process of the turbine. The airflow inside the air turbine was analyzed by changing the shape of the turbine blade using the blade tip width and angle of the turbine blade as the design variables. The variables of the turbine were generated by Minitab and evaluated by the torque. The pressure distribution and torque were obtained and analyzed for each blade shape. The influences of the design variables on the air-turbine performance were analyzed by Analysis of Variance. The blade shape was optimized by comparing the torque values of the various turbine blades. The optimum design variables were found when the blade tip width and angle of the blade were 0.2 mm and 80°, respectively.