Author : Sanika Karande, Nitin Pagar and Sai Pavan Kumar

Turbochargers are used to increase the output power of the engine and make use of the exhaust gases to rotate the impeller which is coupled to the turbine wheel by a shaft. The turbine wheels being manufactured by the process of casting are subjected to possess unbalance in them, which is mainly with respect to the mass distribution. The uneven distribution of material across the wheel back face acts as a stress raiser which may lead to wheel burst in critical conditions. Balancing machines with grinding units are used to balance the turbine wheel with the right amount of material being removed in the units of gram millimeter which is termed as the balance capacity. To achieve maximum material removal, higher values of balance capacity need to be achieved without compromising the stress values of the wheel. Various parameters are considered for achieving the target. The tool used for obtaining the optimum value of the parameters is the design of experiments. The response surface optimization is used in which the design of experiments generates design points for each parameter and gives the optimum value of the parameters to achieve the expected balance capacity and also ensure that the stress is within the acceptable range.

Keywords: Balancing, turbine wheel, imbalance, stress analysis, balance capacity, design of experiments, response surface optimization

Article published in International Journal of Current Engineering and Technology, Vol.6, No.4 (Aug-2016)