Flow study on a newly developed impeller for a left ventricular assist device.
Nowadays, left ventricular assist devices are usually designed as high-speed, electric, rotary blood pumps. The pump drains blood from the left ventricular apex via an inlet cannula and ejects into the aortic root via an outlet conduit. To develop a high-performance pump, the present study utilizes partial differential equations to generate a surface representation of the impeller of the blood pump. Flow analysis around the impeller is performed by using the finite volume method to solve the fully incompressible three-dimensional Navier-Stokes equations along with the k-epsilon turbulence model. The numerical results highlight flow features in the end-wall region of the pump, namely the clearance leakage cross-flow, and the vortex associated with this leakage. These secondary flows induce major energy losses in the pumping device. On the test study, a test loop was proposed to measure the performance characteristics. It was shown that the design would provide a flow rate of 4.4 l/min with a pressure head of 122 mmHg. The DC motor power under these conditions was about 6 W and the rotational speed was 4500 rpm. Both the flow rate and head can satisfy the demand for the left artificial heart to work normally.
Hsu
Cheung-Hwa
CH
Department of Mechanical Engineering, Southern Taiwan University of Technology, 1 Nan-Tai St, Yung-Kang, Tainan Hsien, Taiwan 710, ROC. chhsu@mail.stut.edu.tw
D019295:Computational Biology; D017076:Computer-Aided Design; D020342:Finite Element Analysis; D006353:Heart-Assist Devices; D018056:Hemorheology; D006801:Humans; D008432:Mathematical Computing; D008955:Models, Cardiovascular; D018487:Ventricular Dysfunction, Left / Q000628:therapy*