Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765980
Title: Optimization of geometric characteristics of axial and centrifugal pumps for mechanical circulatory support devices
Author: Mozafari, Sahand
ISNI:       0000 0004 7652 9680
Awarding Body: Queen Mary University of London
Current Institution: Queen Mary, University of London
Date of Award: 2017
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Abstract:
The physiological and clinical considerations of centrifugal and axial pumps as ven- tricular assist devices (VADs) demands limitations on the power, size and geometry of the impellers. A typical pump design method is to rely on the characteristics of previously designed pumps with known performance using empirical equations and nondimensional parameters based on uid dynamics similarity law. Such data are widely available for industrial pumps operating in Reynolds number region of 108. VADs operate in Re < 106 and therefore the similarity concept does not apply between the industrial diagrams and the medical application of small pumps. The present dissertation employs a parametric approached analytical model to in- vestigate more than 150 axial and centrifugal pumps. The design parameters are optimised using the response surface methodology. The effect of different design parameters on the performance, force analysis and hemocompatibility of the pumps is thoroughly investigated by modelling the haemolysis through a power-law equation. The results show an explicit and consistent relationship between the number of blades, outlet width, outlet angle and the hemocompatibility of the device. Centrifu- gal pumps showed signi cantly lower probability of blood complications compared to axial pumps. The evaluation of the design characteristics helps pump designers to select their parameters accordingly for a low probability of blood complications. Furthermore, experimental techniques are employed to test more than 70 pumps in different conditions of flow, pressure and rotational speed. The experimental results validate the numerical simulations and create a database of empirical equations and data points for small axial and centrifugal pumps. The specifi c speed and speci fic diameters of the pumps are plotted on an ns − ds diagram to enable preliminary design of small pumps for VADs suitable for different stages of congestive heart failure (CHF).
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.765980  DOI: Not available
Keywords: Engineering and Materials Science ; Mechanical Circulatory Support Devices ; ventricular assist devices ; congestive heart failure
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