Gap Flow Field Measurements of Bio-Centrifugal Ventricular Assist Device Using Laser Doppler Anemometer

A flow field study in the gap between the impeller and the stationary casing of a bio-centrifugal pump was conducted using laser Doppler anemometer (LDA). Any stagnation flow and high shear stress flow observed is useful to identify the region of possible blood clotting or blood damage. Blood analog that has the similar characteristics as blood was used in this study. The gap flow was found to be smooth with the absence of any standing vortices. It was also found that the existence of the splitter plate of the double volute design has highly affected the gap flow and created a washout mechanism, which could cause the gap flow tended towards the eye of the impeller and successfully prevent the fluid from being stagnated in the gap.