Multiphase flow analysis of hydrodynamic journal bearing using CFD coupled Fluid Structure Interaction considering cavitation

Abstract Fluid Structure Interaction (FSI) models are an essential tool in understanding the complex coupling of blood flow in the heart. The objective of this study is to establish a method of comparing data obtained from FSI models and benchtop measurements from phantoms to identify sources of flow changes for use in intraventricular flow analysis. Two geometries are considered: 1) a vascular model consisting of a straight channel with an ellipsoidal swell and 2) an idealized left ventricle (LV) model representative “acorn” shape. Two phantoms are created for each of the two geometries: 3D printed rigid phantoms from a resin and custom-made tissue-mimicking phantoms from a medical gel. Benchtop measurements are made using the phantoms within a custom flow loop setup with pulsatile flow. Computational Fluid Dynamics (CFD) simulations are conducted with a Smoothed Particle Hydrodynamics (SPH) model. The two flow channel geometries utilized in the experiments are replicated for the simulations. The cavity walls are defined by ghost particles that are rigidly fixed. Maximum pressure drops were 57 mmHg and 196 mmHg for the rigid swell and rigid LV, respectively, whereas maximum pressure drops were 155 mmHg for the gel swell and 140 mmHg for the gel LV. Calculations from the simulations resulted in a maximum pressure drop of 55 mmHg for the swell and 110 mmHg for the LV. This data serves as a first step in corroborating our methodology to utilize the information obtained from both methods to identify and better understand mutual sources of changes in flow patterns.

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Flow analysis of a ribbed helix lip seal with consideration of fluid–structure interaction

Computers & Fluids ◽

10.1016/j.compfluid.2010.10.005 ◽

2011 ◽

Vol 40 (1) ◽

pp. 324-332 ◽

Cited By ~ 4

Author(s):

Chih-Yung Wen ◽

An-Shik Yang ◽

Li-Yu Tseng ◽

Wei-Li Tsai

Keyword(s):

Fluid Structure Interaction ◽

Flow Analysis ◽

Fluid Structure ◽

Lip Seal ◽

Structure Interaction

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Fluid-Structure Interaction Modeling of a Subsea Jumper Pipe

Volume 2: CFD and VIV ◽

10.1115/omae2014-24070 ◽

2014 ◽

Cited By ~ 1

Author(s):

Mohammad A. Elyyan ◽

Yeong-Yan Perng ◽

Mai Doan

Keyword(s):

Multiphase Flow ◽

Numerical Simulations ◽

Numerical Study ◽

Fluid Structure Interaction ◽

Flow Experience ◽

Flow Induced Vibration ◽

Fluid Structure ◽

Structure Interaction ◽

Start Up ◽

Interaction Modeling

Flow-induced vibration (FIV) is one of the main reasons for subsea piping failure, where subsea pipes, which typically carry multiphase flow, experience large fluctuating forces. These fluctuating forces can induce severe vibrations leading to premature piping failure. This paper presents a transient numerical study of a typical subsea M-shape jumper pipe that is carrying a gas-liquid multiphase flow subject to a slug frequency of 4.4 Hz, starting from rest to include the start-up effect as part of the study. 3-D numerical simulations were used to capture the fluid-structure interaction (FSI) and estimate pipe deformations due to fluctuating hydrodynamic forces. In this paper, two FSI approaches were used to compute the pipe deformations, two-way coupled and one-way decoupled. Analysis of the results showed that decoupled (one-way) FSI approach overestimated the peak pipe deformation by about 100%, and showed faster decay of fluctuations than coupled (two-way) FSI analysis. The assessment of resonant risk due to FIV is also discussed.

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