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.
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
Cheung-Hwa
CH
Hsu
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*