Optimization of a centrifugal heart assist pump using computational fluid dynamics

In the first part of this thesis, a study on improving the efficiency of a reference centrifugal heart support pump was carried out by using Taguchi method. Five geometric parameters of the reference pump are optimized at three levels. In the optimization of the geometric parameters, 3150, 3300 and 3450 rpm rotations with a flow rate of 5 L/min were used. Signal/Noise values were calculated from the obtained efficiency results and variance analyzes were performed. The geometric parameters of the optimal pump were obtained taking into account the maximum values of the average S/N. The solid model of the optimum pump obtained was created and the performance of the optimal pump was determined by making HAD simulations. As a result, it was understood that the efficiency of the reference pump could be improved considerably. In the second part of the study, the effects of changes in viscosity on the pump hydraulic performance were investigated in the range of 0.002-0.006 kg/m.s. At the end of the research, depending on the viscosity increase; a decrease in total pressure and an increase in pump power were observed at constant flow rate. As a result, it was seen that as the viscosity increases, there is a significant decrease in pump efficiency. In the last part of this study, the prototypes of the optimum and the reference pump designed in the optimization study were produced and they were subjected to experimental tests using a water-glycerin solution. The hydraulic performances of these pumps were determined and compared. The pressure difference and efficiency of the optimum pump were found to be better than that of the reference pump.