Correlating the Experiment and Fluid Structure Interaction Results of a Suction Valve Model from a Hermetic Reciprocating Compressor

2017 ◽  
Author(s):  
John Samuel Kopppula ◽  
Thundil Karuppa Raj Rajagopal ◽  
Edison Gundabattini
Keyword(s):  
Fluid Structure Interaction ◽  
Reciprocating Compressor ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Valve Model

Computational Modeling of Aortic Stenosis with a Reduced Degree-Of-Freedom Fluid-Structure Interaction Valve Model

2021 ◽  
Author(s):  
Chi Zhu ◽  
Jung-Hee Seo ◽  
Rajat Mittal
Keyword(s):  
Aortic Stenosis ◽  
Pressure Fluctuations ◽  
Fluid Structure Interaction ◽  
Degree Of Freedom ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Deceleration Phase ◽  
Wall Pressure Fluctuations ◽  
Two Parameters ◽  
Valve Model

Abstract In this study, a novel reduced degree-of-freedom (rDOF) aortic valve model is employed to investigate the fluid-structure interaction and hemodynamics associated with aortic stenosis. The dynamics of the valve leaflets are determined by an ordinary differential equation with two parameters and this rDOF model is shown to reproduce key features of more complex valve models. The hemodynamics associated with aortic stenosis is studied for three cases: a healthy case and two stenosed cases. The focus of the study is to correlate the hemodynamic features with the source generation mechanism of systolic murmurs associated with aortic stenosis. In the healthy case, extremely weak flow fluctuations are observed. However, in the stenosed cases, simulations show significant turbulent fluctuations in the asending aorta, which are responsible for the generation of strong wall pressure fluctuations after the aortic root mostly during the deceleration phase of the systole. The intensity of the murmur generation increases with the severity of the stenosis, and the source locations for the two diseased cases studied here lies around 1.0 inlet duct diameters ($D_o$) downstream of the ascending aorta.

Thermo-Fluid-Dynamic Design of Reciprocating Compressor Cylinders by Fluid Structure Interaction (FSI)

2011 ◽  
Author(s):  
Riccardo Traversari ◽  
Alessandro Rossi ◽  
Marco Faretra
Keyword(s):  
High Speed ◽  
Fluid Dynamic ◽  
Fluid Structure Interaction ◽  
Classical Equation ◽  
Flow Coefficient ◽  
Reciprocating Compressor ◽  
Complex Situation ◽  
Fluid Structure ◽  
Associated Gas ◽  
Structure Interaction

Pressure losses at the cylinder valves of reciprocating compressors are generally calculated by the classical equation of the flow through an orifice, with flow coefficient determined in steady conditions. Rotational speed has increased in the last decade to reduce compressor physical dimensions, weight and cost. Cylinder valves and associated gas passages became then more and more critical, as they determine specific consumption and throughput. An advanced approach, based on the new Fluid Structure Interaction (FSI) software, which allows to deal simultaneously with thermodynamic, motion and deformation phenomena, was utilized to simulate the complex situation that occurs in a reciprocating compressor cylinder during the motion of the piston. In particular, the pressure loss through valves, ducts and manifolds was investigated. A 3D CFD Model, simulating a cylinder with suction and discharge valves, was developed and experimentally validated. The analysis was performed in transient and turbulent condition, with compressible fluid, utilizing a deformable mesh. The 3D domain simulating the compression chamber was considered variable with the law of motion of the piston and the valve rings mobile according to the fluid dynamic forces acting on them. This procedure is particularly useful for an accurate valve loss evaluation in case of high speed compressors and heavy gases. Also very high pressure cylinders, including LDPE applications, where the ducts are very small and MW close to the water one, can benefit from the new method.

scholarly journals A finite strain nonlinear human mitral valve model with fluid-structure interaction

2014 ◽  
Vol 30 (12) ◽  
pp. 1597-1613 ◽  
Author(s):  
Hao Gao ◽  
Xingshuang Ma ◽  
Nan Qi ◽  
Colin Berry ◽  
Boyce E. Griffith ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Finite Strain ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Valve Model

scholarly journals Fluid-structure interaction and structural analyses using a comprehensive mitral valve model with 3D chordal structure

2016 ◽  
Vol 33 (4) ◽  
pp. e2815 ◽  
Author(s):  
Milan Toma ◽  
Daniel R. Einstein ◽  
Charles H. Bloodworth ◽  
Richard P. Cochran ◽  
Ajit P. Yoganathan ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Valve Model

scholarly journals Fluid-Structure Interaction Analysis of Subject-Specific Mitral Valve Regurgitation Treatment with an Intra-Valvular Spacer

Prosthesis ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 65-75 ◽  
Author(s):  
Milan Toma ◽  
Daniel R. Einstein ◽  
Charles H. Bloodworth ◽  
Keshav Kohli ◽  
Richard P. Cochran ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Mitral Valve Regurgitation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Mitral Regurgitation Severity ◽  
Subject Specific ◽  
Valve Model

Mitral regurgitation imposes a significant symptomatic burden on patients who are not candidates for conventional surgery. For these patients, transcatheter repair and replacement devices are emerging as alternative options. One such device is an intravalvular balloon or spacer that is inserted between the mitral valve leaflets to fill the gap that gives rise to mitral regurgitation. In this study, we apply a large-deformation fluid-structure interaction analysis to a fully 3D subject-specific mitral valve model to assess the efficacy of the intra-valvular spacer for reducing mitral regurgitation severity. The model includes a topologically 3D subvalvular apparatus with unprecedented detail. Results show that device fixation and anchoring at the location of the subject’s regurgitant orifice is imperative for optimal reduction of mitral regurgitation.

Virtual Prototyping Technique Applied to the Design of a Process Reciprocating Compressor

2011 ◽  
Author(s):  
Riccardo Traversari ◽  
Alessandro Rossi ◽  
Marco Faretra
Keyword(s):  
Fluid Dynamic ◽  
Virtual Prototyping ◽  
Fluid Structure Interaction ◽  
Multiaxial Fatigue ◽  
Reciprocating Compressor ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Rotating Machine ◽  
Multibody Dynamic ◽  
Structural Assembly

Virtual Prototyping (VP) reproduces a complete machine to test it several times, as a scale 1:1 laboratory prototype. VP utilizes various CAE tools, such as 3D modelling, Structural FEA, Multibody Dynamic Analysis (MDA), Multiaxial fatigue analysis, and Fluid Structure Interaction (FSI) in an integrated way. The VP of a rotating machine allows considering a realistic stepless loading pattern throughout the complete revolution and determining automatically the fatigue safety factors within the whole machine structural assembly, while FSI allows dealing simultaneously with thermodynamic, motion and deformation phenomena. This approach was used to review the design of the crank mechanism and cylinders of an existing reciprocating compressor. The loads (including inertia forces) were applied to the gudgeon pin and, by means of the MDA, to all the other components. An advanced approach, based on Fluid Structure Interaction (FSI) analysis, was applied for the thermodynamic analysis of the cylinder’s efficiency. A 3D CFD Model, simulating the cylinder with mobile piston and valves, was developed and experimentally validated. The 3D domain simulating the compression chamber changes with the piston motion law while valve rings move according to the fluid dynamic forces.

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