Preliminary design and optimization of an ECC blood pump by means of a parametric approach.

This study concerns the development of an analytical parametric model of a centrifugal disk pump. The advantage of this kind of approach is to have an adaptable tool as a first step for the design of a pump device. The method allows the evaluation of the velocity profiles and the shear stresses within the impeller disks in the flow domain along with the performance of the device in terms of torque, mechanical power, power loss, head-flow performance, pump efficiency, and hemolytic index. Some simplifying hypotheses are assumed: steady state condition, laminar flow, Newtonian and incompressible fluid. The radial velocity profiles are assumed to be uniform and the flow cross-sectional area is assumed to be constant along the radius. The influence of the housing and secondary flows caused by recirculation are neglected. To test the approach reliability, the model was used to simulate a pump with the following characteristics: an external and internal radius of 50 mm and 5 mm, respectively, and a channel height of 2.5-0.25 mm (h) from inlet to outlet section. The angular velocity omega was varied in the range 500-3,000 rpm. The flow rate has been varied from 1 to 5 L/min. The results show that when the flow rate is increased, head performances obtained using this pump model vary from 411 to 100 mm Hg, and its efficiency varies from 48 to 15%. A parallel simulation has been carried out by means of a Finite Element Method model with an angular velocity equal to 2,000 rpm.(ABSTRACT TRUNCATED AT 250 WORDS)