Dynamic Behavior of Reciprocating Plunger Pump Discharge Valve Based on Fluid Structure Interaction and Experimental Analysis

Vascular prostheses used for repairing and replacing damaged and diseased the thoracic aorta in cases of aneurysm, dissection or coarctation have distinctly different mechanical properties than the native aorta. Very little is known about the dynamic behavior of vascular prostheses that can cause unwanted hemodynamic effects leading to their failure. In this study, a Dacron reconstitution of the aorta is modelled as an isotropic cylindrical shell by means of nonlinear Novozhilov shell theory. A numerical bifurcation analysis employs a refined reduced order model to investigate the dynamic behavior of a pressurized Dacron aortic replacement conveying blood flow. A pulsatile time-dependent blood flow model is considered in order to study the effect of pressurization by applying physiological waveforms of velocity and pressure during the heart beating period. Stresses due to pressurization are evaluated and included in the model. The fluid is modeled as a Newtonian pulsatile flow and it is formulated using a hybrid model that contains the unsteady effects obtained from the linear potential flow theory and the pulsatile viscous effects obtained from the unsteady time-averaged Navier-Stokes equations. Geometrically non-linear vibration response to pulsatile flow is here presented via frequency-response curves and time histories. This study provides a fully coupled fluid-structure interaction model and it allows deep insights in the mechanical loading condition of the aortic replacements; this insight has potential to aid in vascular prostheses design and implementation.

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Investigation on dynamic characteristics of a plate-type discharge valve in a diaphragm pump for SCR system by two-way FSI model

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407019862168 ◽

2019 ◽

Vol 234 (4) ◽

pp. 1197-1209

Author(s):

Youcheng Shi ◽

Shudong Yang ◽

Xiwei Pan ◽

Yinshui Liu

Keyword(s):

Numerical Model ◽

Fluid Structure Interaction ◽

Interaction Model ◽

Valve Plate ◽

Fluid Structure ◽

Diaphragm Pump ◽

Pump Speed ◽

Structure Interaction ◽

Discharge Valve ◽

Plate Type

A plate-type port valve with rubber valve plate in a miniature diaphragm pump is presented. To investigate the dynamic characteristics of this type of discharge valve, a two-way fluid structure interaction model is proposed. The interaction between the dynamic behavior of the fluid and rubber is considered in the fluid structure interaction model. Based on the fluid structure interaction model, the internal flow of the pump, the deflection of the diaphragm and discharge valve plate is calculated. To verify the validity of the numerical model, a prototype pump is fabricated and tested. The experimental pressures in the working chamber of the pump show the same overall trends with the numerical results. The deviations between the numerical and experimental flowrates are less than 7.2%. The experimental results prove that the numerical model is effective in predicting a complete discharge process of the pump. There is a big difference between the deflection of the center of the valve plate and the edge of the valve plate. The oscillation period of the pressure in the working chamber of the pump is approximately double that of the discharge valve plate. When the pump speed is lower than 2500 r/min, it has little influence on the lag angles of the discharge valve under rated pressure. The lag angles at rated pump speed increase when the backpressures increase. The stress of the discharge valve plate reaches a peak when the valve plate impact on the valve limiter or valve seat.

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Fluid-Structure Interaction in Abdominal Aortic Aneurysms: Effect of Haematocrit

Fluids ◽

10.3390/fluids4010011 ◽

2019 ◽

Vol 4 (1) ◽

pp. 11 ◽

Cited By ~ 6

Author(s):

Yorgos Stergiou ◽

Athanasios Kanaris ◽

Aikaterini Mouza ◽

Spiros Paras

Keyword(s):

Blood Flow ◽

Dynamic Behavior ◽

Blood Viscosity ◽

Arterial Wall ◽

Fluid Structure Interaction ◽

Aortic Aneurysms ◽

Patient Specific ◽

Fluid Structure ◽

Structure Interaction ◽

Abdominal Aortic

The Abdominal Aortic Aneurysm (AAA) is a local dilation of the abdominal aorta and it is a cause for serious concern because of the high mortality associated with its rupture. Consequently, the understanding of the phenomena related to the creation and the progression of an AAA is of crucial importance. In this work, the complicated interaction between the blood flow and the AAA wall is numerically examined using a fully coupled Fluid-Structure Interaction (FSI) method. The study investigates the possible link between the dynamic behavior of an AAA and the blood viscosity variations attributed to the haematocrit value, while it also incorporates the pulsatile blood flow, the non-Newtonian behavior of blood and the hyperelasticity of the arterial wall. It was found that blood viscosity has no significant effect on von Mises stress magnitude and distribution, whereas there is a close relation between the haematocrit value and the Wall Shear Stress (WSS) magnitude in AAAs. This WSS variation can possibly alter the mechanical properties of the arterial wall and increase its growth rate or even its rupture possibility. The relationship between haematocrit and dynamic behavior of an AAA can be helpful in designing a patient specific treatment.

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