| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 92 === Abstract
Electro-Hydraulic power is the driving mechanism adopted on the NCKU Left Ventricular Assist Device (LVAD) and Total Artificial Heart (TAH). The huge size of conventional pneumatic driving system would cause great inconvenience to the patients in post-surgical daily life. The development of this hydraulic system can significantly reduce the volume of the driver, and the patients can acquire good activity and better quality of life as well. For this purpose, a practical and highly effective hydraulic pump design is one of the most important tasks while developing the NCKU LAVD and TAH. Commercial-used Computational Fluid Dynamics (CFD) softwares are utilized here to analyze the performance of current mixed-flow pump. Two flow field conditions, running channels with straight pipe and curved-surface pipe upstream/downstream respectively, are considered in this research. Simulating results are compared to the experimental ones, and provide reference material to further hydraulic system design and geometric modification of the channel shape. The results show that the performance of this hydraulic pump in straight running channel conforms to the designed requirements, and the computational results correspond to the experimental ones as well. However, the pump performance in the curved-surface running channel is contrary to expectation in that the flow gets into the hydraulic pump and is pressurized immediately after passing the upstream curved pipe, and then flows out by the downstream curved pipe after being pressurizing. At operation point, the influence of curved-surface running channel cost pump by 68.7mmHg pressure lose and 17% efficiency loss. In all, this hydraulic pump can really achieve the required effect. Nevertheless, being put in the LVAD or TAH, the hydraulic pump has to be re-designed on the special running channel.
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