Effect of tip clearance on wall shear stress of an axial LVAD

2nd International Conference on Computational Fluid Dynamics in Research and Industry

力学;计算机科学;工业技术

Sarath, S.^1 ; Vikas, R.^1

Dept of Mechanical Engineering, Amrita School of Engineering, Amritapuri, Amrita Vishwa Vidhyapeetham, Amrita University, India^1

关键词: Blade Surface;    Constant thickness;    Crucial parameters;    Initial design;    Major factors;    Pump efficiency;    Varying thickness;    Wall shear stress;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/243/1/012010/pdf
DOI  :  10.1088/1757-899X/243/1/012010

来源: IOP

【 摘 要 】

Wall shear stress is a crucial parameter used for blood damage analysis, and typically a value of 400 Pa is set as a limit. Tip clearance is a major factor contributing to hemolysis and pump efficiency. In this study, different tip gap configurations are used to analyse the wall shear stress developed on the blade surface of a constant thickness blade design, and a varying thickness blade design using CFD analysis. It was found that, for a particular geometry, as the clearance gap reduces, flow rate over the high wall shear stress area decreases even though the high wall shear stress span is found to extend. For each design, the optimum clearance gap is iteratively attained, keeping the maximum WSS as a limiting factor. Thus a better pump designs is obtained, whose leakage flow patterns are lower than that of the initial design, hence also leading to higher pump efficiency.