Flow investigation in a centrifugal pump

Abstract

With increasing people suffering from cardiovascular diseases, it has led to an increase in the demand for Ventricular Assist Devices (VAD). There are mainly two categories of VAD devices and centrifugal pumps are one of categories that can be used to aid a failing heart. However, there are also possible cons to using VADs, this cons are mainly hemolysis and thrombus formation in centrifugal pumps. Therefore, the main purpose of this experiment is to investigate the leakage flow in the pump that may cause this thrombus formation and hemolysis. A Computational Fluid Dynamics (CFD) analysis of the centrifugal pump model will be done using ANSYS V14.5. In the pump model, there are mainly two leakage gap, one in front of the outer volute and the other in the back of the outer volute. There are mainly 4 leakage gap heights ranging from 0.2mm to 0.5mm and each gap height will operate at 1500rpm, 2000rpm and 2500rpm. The operating flow rate of the model can range from 2lpm to 5lpm. From the experiment, it can be observed that the leakage flow depends on several factors. This includes the leakage gap heights, rotational speed and the pressure difference within the leakage gaps. The leakage flow was observed to increase with the increase in leakage gap heights, rotational speeds and pressure difference.