the dynamic of fluid and structure waves along a flexible tubes allow valveless and bladeless pumping at specific exitation frequrncies. the presentation describes different medical applications for this pump and the numerical method to analyse its capabilities
by Dr. Idit Avrahami
Reservoir rocks experience compaction when fluid is produced, causing a change in pore volume and effective stress. There are three types of compressibility - rock matrix (grain) compressibility measures change in grain volume, rock bulk compressibility measures change in total formation volume, and pore volume compressibility measures change in pore space. Accurately measuring and modeling compressibility is important for predicting changes in porosity and formation properties during production.
This document provides information on estimating oil and gas reserves. It defines various classifications of reserves from proven to unproven, and how reserves are estimated using volumetric, material balance, and production performance methods. The key classifications discussed are proven and probable reserves, with proven reserves having a 90% certainty of recovery and probable having 50% certainty. Volumetric estimation calculates initial hydrocarbon volumes using parameters like rock volume, porosity, fluid properties, and recovery factors.
1) The document discusses methods for determining reservoir pressure gradients, depths of fluid interfaces like gas-oil and oil-water contacts, and pressures at various points from measured well data.
2) Equations are provided to calculate pressure gradients between two depths, depths of hydrocarbon interfaces using gradients above and below the interface, and pressures at perforations or contacts using the gradient and depth.
3) An example problem demonstrates calculating gradients, gas-oil contact depth, oil-water contact depth, and pressures at the contacts and perforations using a table of depth and pressure measurements.
This document provides an overview of key concepts in drilling engineering related to pore pressure prediction and fracture gradient determination. It discusses how pore pressures are estimated based on geology, porosity logs, and seismic data. Formations can be normally or abnormally pressured depending on factors like compaction. Leak-off tests are used to directly measure fracture gradients and determine maximum safe mud weights. Understanding pore pressure and fracture gradients is essential for well planning activities like mud weight selection and casing design.
This document provides an overview of well completion processes and equipment. It describes common casing types like surface casing, intermediate casing, and production casing. It explains the functions of casing to protect the wellbore, isolate fluid zones, and provide a conduit for tools. The document outlines the typical steps in a well completion, including running and cementing casing, perforating, stimulating, gravel packing if needed, and installing tubing and a Christmas tree. It provides details on related equipment like centralizers, float shoes, and packers. The document is intended as an introduction to well completion concepts and components for educational purposes.
Introduction to Reservoir Rock & Fluid PropertiesM.T.H Group
This document discusses reservoir rock properties and how core samples are used to characterize reservoirs. Reservoir rocks must have porosity and permeability to store and transmit fluids. Core samples provide information on lithology, porosity, permeability and other properties essential for evaluating a reservoir's fluid storage and flow capabilities. Whole core samples are most representative but sidewall cores provide additional data points. Both core types are analyzed to understand factors like relative permeability needed for reservoir modeling and production forecasting.
Mo ch 1_properties of particulate solid_complete_10.12.2020Dhaval Yadav
Properties of Particulate Solids
Fundamentals of Unit operation and Unit process
Specific properties of solids
Particle density and Bulk density
Sphericity,
Equivalent diameter,
Specific surface area,
Volume surface mean diameter, mass mean diameter, and shape factor
This document discusses drilling fluids and cementing processes used in oil and gas drilling operations. It defines drilling mud as a fluid mixture used to carry rock cuttings to the surface and lubricate/cool the drill bit. Mud engineers are responsible for testing and treating the mud. The main types of drilling mud are water-based, oil-based, and synthetic-based. Cementing involves pumping cement slurry into the annular space between the casing and borehole to secure the casing and prevent fluid migration. Primary cementing is the initial process, while secondary cementing repairs or improves the primary cement job through techniques like squeeze cementing and plug cementing. Common cement types used include Portland cement, oil well cement, Class
Reservoir rocks experience compaction when fluid is produced, causing a change in pore volume and effective stress. There are three types of compressibility - rock matrix (grain) compressibility measures change in grain volume, rock bulk compressibility measures change in total formation volume, and pore volume compressibility measures change in pore space. Accurately measuring and modeling compressibility is important for predicting changes in porosity and formation properties during production.
This document provides information on estimating oil and gas reserves. It defines various classifications of reserves from proven to unproven, and how reserves are estimated using volumetric, material balance, and production performance methods. The key classifications discussed are proven and probable reserves, with proven reserves having a 90% certainty of recovery and probable having 50% certainty. Volumetric estimation calculates initial hydrocarbon volumes using parameters like rock volume, porosity, fluid properties, and recovery factors.
1) The document discusses methods for determining reservoir pressure gradients, depths of fluid interfaces like gas-oil and oil-water contacts, and pressures at various points from measured well data.
2) Equations are provided to calculate pressure gradients between two depths, depths of hydrocarbon interfaces using gradients above and below the interface, and pressures at perforations or contacts using the gradient and depth.
3) An example problem demonstrates calculating gradients, gas-oil contact depth, oil-water contact depth, and pressures at the contacts and perforations using a table of depth and pressure measurements.
This document provides an overview of key concepts in drilling engineering related to pore pressure prediction and fracture gradient determination. It discusses how pore pressures are estimated based on geology, porosity logs, and seismic data. Formations can be normally or abnormally pressured depending on factors like compaction. Leak-off tests are used to directly measure fracture gradients and determine maximum safe mud weights. Understanding pore pressure and fracture gradients is essential for well planning activities like mud weight selection and casing design.
This document provides an overview of well completion processes and equipment. It describes common casing types like surface casing, intermediate casing, and production casing. It explains the functions of casing to protect the wellbore, isolate fluid zones, and provide a conduit for tools. The document outlines the typical steps in a well completion, including running and cementing casing, perforating, stimulating, gravel packing if needed, and installing tubing and a Christmas tree. It provides details on related equipment like centralizers, float shoes, and packers. The document is intended as an introduction to well completion concepts and components for educational purposes.
Introduction to Reservoir Rock & Fluid PropertiesM.T.H Group
This document discusses reservoir rock properties and how core samples are used to characterize reservoirs. Reservoir rocks must have porosity and permeability to store and transmit fluids. Core samples provide information on lithology, porosity, permeability and other properties essential for evaluating a reservoir's fluid storage and flow capabilities. Whole core samples are most representative but sidewall cores provide additional data points. Both core types are analyzed to understand factors like relative permeability needed for reservoir modeling and production forecasting.
Mo ch 1_properties of particulate solid_complete_10.12.2020Dhaval Yadav
Properties of Particulate Solids
Fundamentals of Unit operation and Unit process
Specific properties of solids
Particle density and Bulk density
Sphericity,
Equivalent diameter,
Specific surface area,
Volume surface mean diameter, mass mean diameter, and shape factor
This document discusses drilling fluids and cementing processes used in oil and gas drilling operations. It defines drilling mud as a fluid mixture used to carry rock cuttings to the surface and lubricate/cool the drill bit. Mud engineers are responsible for testing and treating the mud. The main types of drilling mud are water-based, oil-based, and synthetic-based. Cementing involves pumping cement slurry into the annular space between the casing and borehole to secure the casing and prevent fluid migration. Primary cementing is the initial process, while secondary cementing repairs or improves the primary cement job through techniques like squeeze cementing and plug cementing. Common cement types used include Portland cement, oil well cement, Class
The document discusses compaction and subsidence that can occur during oil and gas production due to a reduction in pore pressure. It describes how effective stress increases as pore pressure declines, causing the reservoir rock to compact. This compaction at the reservoir level can result in subsidence at the surface. Key factors that influence compaction and subsidence are identified as reservoir rock properties, thickness, pore pressure depletion, and areal extent. The ratio between subsurface compaction and surface subsidence is also addressed.
Fundamentals of Petroleum Engineering Module 5Aijaz Ali Mooro
This document provides an overview of formation evaluation techniques including: mud logging to analyze drill cuttings; coring to obtain formation samples; open-hole logging using tools to measure electrical, acoustic, and radioactive properties; logging while drilling to obtain logs in real-time; formation testing to obtain pressure and fluid samples; and cased-hole logging for production monitoring and reservoir analysis. The goal of formation evaluation is to interpret measurements taken inside the wellbore to characterize reservoirs and quantify hydrocarbon reserves in the surrounding rock.
Fluid saturations refer to the fraction of pore volume occupied by water, oil, or gas in a reservoir. The sum of all fluid saturations must equal 1. Fluid saturations can be measured directly from core analysis under reservoir conditions or indirectly from well log or capillary pressure analysis. Factors like drilling mud composition and changes in pressure/temperature can affect measured fluid saturations in cores. While core saturations may not accurately reflect reservoir saturations, they provide useful information on fluid contacts, minimum water saturations, and validation of indirect methods.
Introduction Effective Permeability & Relative PermeabilityM.T.H Group
Effective and relative permeability data are used to quantify fluid flow in reservoirs containing multiple phases. Effective permeability measures the flow of a single phase in a multi-phase system, while relative permeability expresses effective permeability as a ratio of absolute permeability. Relative permeability curves describe how the flow of each phase varies with saturation. They are influenced by factors like pore structure, wettability, and saturation history, and are important inputs for reservoir simulation and other multiphase flow calculations.
The document discusses the functions and types of casing strings used in oil and gas wells. It describes the different casing strings like conductor casing, surface casing, intermediate casing, and production casing. It also covers casing design criteria like classifications based on outside diameter, length, connections, weight, and grade. The mechanical properties of casing are discussed in relation to withstanding tensile, burst, and collapse loads during drilling and production operations.
This document discusses drilling engineering and hydraulics. It covers topics such as mud weight planning, pore pressure prediction, fracture gradients, and drilling hydraulics concepts like hydrostatic pressure. Maintaining the proper mud weight and hydrostatic pressure is important for well control and avoiding drilling problems. Both too low and too high of a mud weight can cause issues like wellbore instability, lost circulation, or differential sticking. The document recommends following the median line concept and making gradual changes to mud weight.
Porosity Permeability Relationship in carbonate rock pptAmar Gaikwad
A information about porosity and permeability in a carbonate rock. in which we studied the porosity measurement , carbonate rock ,permeability and correlation between them.
This document discusses casing design and selection for oil and gas wells. It begins by explaining the functions of different casing strings, including conductor, surface, intermediate, production casing, and liners. Key factors in determining casing setting depths are discussed, such as mud weight profiles, formation pressures, and hole sizes. Common casing sizes and connections are also outlined. Proper casing design is important for well integrity and cost-effectiveness of the drilling project.
The document covers reservoir engineering concepts including solutions to the diffusivity equation for radial flow of single-phase and compressible fluids. It discusses the pD and Ei-function solutions, and presents the unified steady-state flow regime equations for radial flow of single-phase and compressible fluids using the pD-function, m(p)-function, and pressure-squared approximations. It also covers the pseudo-steady state flow regime and relationships between pressure functions.
This document provides an overview of mass transfer concepts and principles. It begins with an introduction and outlines the topics that will be covered, which include equilibrium fundamentals, molecular diffusion, convective mass transfer, interphase mass transfer, and a conclusion. Each topic is then broken down into further subsections. For example, molecular diffusion covers Fick's law and its various cases. The document provides learning objectives for understanding concepts related to vapor-liquid equilibrium and mass transfer applications in industry. It also includes recommendations for reference books on these topics and notes for students on using the teaching materials.
That is my presentation for my grad research about reservoir geomechanics, hope you find it useful, and my source book was reservoir geomechanics for prof Mark Zoback, soon the PDF copy will be available as well.
The document discusses several methods for predicting fracture gradients: Hubbert & Willis, Matthews & Kelly, and Ben Eaton. It provides examples of calculating fracture gradients for a Texas Gulf Coast well using each method and summarizes the results. Experimental determination of fracture gradients using leak-off tests is also addressed. The Ben Eaton method is considered the most accurate as it accounts for variations in pore pressure, overburden stress, and Poisson's ratio.
The document provides an overview of a course on reservoir fluid properties. It covers the following topics:
1. An introduction to petroleum engineering and the importance of understanding reservoir fluids.
2. The formation and extraction of petroleum, including drilling and production.
3. The constituents of reservoir fluids including hydrocarbon components like methane, paraffins, naphthenes and aromatics. It also discusses non-hydrocarbon components like water, nitrogen and carbon dioxide.
4. The phase behavior of pure components and mixtures, including phase envelopes and using pressure-temperature and pressure-volume diagrams to illustrate behavior.
This document provides an overview of the well drilling and casing process. It discusses the different types of casing used in wells, including conductor, surface, intermediate, production casing, and liners. It describes the purpose and typical specifications of each casing type. The document also includes diagrams of a typical well casing arrangement and an example well survey.
The document discusses inflow performance relationships (IPRs), which represent the relationship between flow rate from a reservoir to a wellbore and bottomhole pressure. It covers IPRs for single-phase, two-phase, and three-phase flow. For single-phase flow, the IPR shows a linear relationship between flow rate and pressure. For two-phase and three-phase flow, the presence of additional phases like gas causes the IPR curve to deviate from linear. The document also discusses methods for predicting future IPR curves based on changes in parameters like reservoir pressure and productivity index over time.
A cement bond log (CBL) measures the loss of acoustic energy as it passes through casing to evaluate the integrity of cement bonding between the casing and formation. A sonic tool detects the bond by transmitting acoustic waves and measuring the amplitude of reflected waves, with lower amplitudes indicating better cement bonding. CBLs are used to detect cement bonding, which is important for supporting the casing, preventing fluid leaks, and isolating zones. Interpreters look for intervals of continuous cement bonding indicated by amplitudes below thresholds like 10 mV over a minimum distance.
The document discusses workover jobs, which refer to interventions done on oil and gas wells to repair downhole equipment and address reservoir issues affecting production. Workovers are necessary when mechanical failures occur or reservoir conditions change. Common reasons for workovers include replacing damaged equipment, fixing casing issues, removing stuck tools, and addressing natural reservoir damage or depletion that reduces productivity. Workovers can involve complex operations like milling packers, fishing operations, and zone recompletions to restore or boost well production.
Brand, Branding and Marketing for Protection Services ProfessionalsLarry Snow
This document discusses branding, marketing, and using social media to establish a brand. It defines a brand as a company's core values and personality. Branding involves activities to get the brand known in the marketplace, like social media marketing, blogging, and communication. Consistency across channels and representing the brand through interactions are important. Marketing involves setting goals, having a strategy, and measuring success through analytics and engagement. The document recommends using social media as a tool to extend the brand by connecting with followers, sharing relevant content, and managing the brand presence across channels.
The document discusses compaction and subsidence that can occur during oil and gas production due to a reduction in pore pressure. It describes how effective stress increases as pore pressure declines, causing the reservoir rock to compact. This compaction at the reservoir level can result in subsidence at the surface. Key factors that influence compaction and subsidence are identified as reservoir rock properties, thickness, pore pressure depletion, and areal extent. The ratio between subsurface compaction and surface subsidence is also addressed.
Fundamentals of Petroleum Engineering Module 5Aijaz Ali Mooro
This document provides an overview of formation evaluation techniques including: mud logging to analyze drill cuttings; coring to obtain formation samples; open-hole logging using tools to measure electrical, acoustic, and radioactive properties; logging while drilling to obtain logs in real-time; formation testing to obtain pressure and fluid samples; and cased-hole logging for production monitoring and reservoir analysis. The goal of formation evaluation is to interpret measurements taken inside the wellbore to characterize reservoirs and quantify hydrocarbon reserves in the surrounding rock.
Fluid saturations refer to the fraction of pore volume occupied by water, oil, or gas in a reservoir. The sum of all fluid saturations must equal 1. Fluid saturations can be measured directly from core analysis under reservoir conditions or indirectly from well log or capillary pressure analysis. Factors like drilling mud composition and changes in pressure/temperature can affect measured fluid saturations in cores. While core saturations may not accurately reflect reservoir saturations, they provide useful information on fluid contacts, minimum water saturations, and validation of indirect methods.
Introduction Effective Permeability & Relative PermeabilityM.T.H Group
Effective and relative permeability data are used to quantify fluid flow in reservoirs containing multiple phases. Effective permeability measures the flow of a single phase in a multi-phase system, while relative permeability expresses effective permeability as a ratio of absolute permeability. Relative permeability curves describe how the flow of each phase varies with saturation. They are influenced by factors like pore structure, wettability, and saturation history, and are important inputs for reservoir simulation and other multiphase flow calculations.
The document discusses the functions and types of casing strings used in oil and gas wells. It describes the different casing strings like conductor casing, surface casing, intermediate casing, and production casing. It also covers casing design criteria like classifications based on outside diameter, length, connections, weight, and grade. The mechanical properties of casing are discussed in relation to withstanding tensile, burst, and collapse loads during drilling and production operations.
This document discusses drilling engineering and hydraulics. It covers topics such as mud weight planning, pore pressure prediction, fracture gradients, and drilling hydraulics concepts like hydrostatic pressure. Maintaining the proper mud weight and hydrostatic pressure is important for well control and avoiding drilling problems. Both too low and too high of a mud weight can cause issues like wellbore instability, lost circulation, or differential sticking. The document recommends following the median line concept and making gradual changes to mud weight.
Porosity Permeability Relationship in carbonate rock pptAmar Gaikwad
A information about porosity and permeability in a carbonate rock. in which we studied the porosity measurement , carbonate rock ,permeability and correlation between them.
This document discusses casing design and selection for oil and gas wells. It begins by explaining the functions of different casing strings, including conductor, surface, intermediate, production casing, and liners. Key factors in determining casing setting depths are discussed, such as mud weight profiles, formation pressures, and hole sizes. Common casing sizes and connections are also outlined. Proper casing design is important for well integrity and cost-effectiveness of the drilling project.
The document covers reservoir engineering concepts including solutions to the diffusivity equation for radial flow of single-phase and compressible fluids. It discusses the pD and Ei-function solutions, and presents the unified steady-state flow regime equations for radial flow of single-phase and compressible fluids using the pD-function, m(p)-function, and pressure-squared approximations. It also covers the pseudo-steady state flow regime and relationships between pressure functions.
This document provides an overview of mass transfer concepts and principles. It begins with an introduction and outlines the topics that will be covered, which include equilibrium fundamentals, molecular diffusion, convective mass transfer, interphase mass transfer, and a conclusion. Each topic is then broken down into further subsections. For example, molecular diffusion covers Fick's law and its various cases. The document provides learning objectives for understanding concepts related to vapor-liquid equilibrium and mass transfer applications in industry. It also includes recommendations for reference books on these topics and notes for students on using the teaching materials.
That is my presentation for my grad research about reservoir geomechanics, hope you find it useful, and my source book was reservoir geomechanics for prof Mark Zoback, soon the PDF copy will be available as well.
The document discusses several methods for predicting fracture gradients: Hubbert & Willis, Matthews & Kelly, and Ben Eaton. It provides examples of calculating fracture gradients for a Texas Gulf Coast well using each method and summarizes the results. Experimental determination of fracture gradients using leak-off tests is also addressed. The Ben Eaton method is considered the most accurate as it accounts for variations in pore pressure, overburden stress, and Poisson's ratio.
The document provides an overview of a course on reservoir fluid properties. It covers the following topics:
1. An introduction to petroleum engineering and the importance of understanding reservoir fluids.
2. The formation and extraction of petroleum, including drilling and production.
3. The constituents of reservoir fluids including hydrocarbon components like methane, paraffins, naphthenes and aromatics. It also discusses non-hydrocarbon components like water, nitrogen and carbon dioxide.
4. The phase behavior of pure components and mixtures, including phase envelopes and using pressure-temperature and pressure-volume diagrams to illustrate behavior.
This document provides an overview of the well drilling and casing process. It discusses the different types of casing used in wells, including conductor, surface, intermediate, production casing, and liners. It describes the purpose and typical specifications of each casing type. The document also includes diagrams of a typical well casing arrangement and an example well survey.
The document discusses inflow performance relationships (IPRs), which represent the relationship between flow rate from a reservoir to a wellbore and bottomhole pressure. It covers IPRs for single-phase, two-phase, and three-phase flow. For single-phase flow, the IPR shows a linear relationship between flow rate and pressure. For two-phase and three-phase flow, the presence of additional phases like gas causes the IPR curve to deviate from linear. The document also discusses methods for predicting future IPR curves based on changes in parameters like reservoir pressure and productivity index over time.
A cement bond log (CBL) measures the loss of acoustic energy as it passes through casing to evaluate the integrity of cement bonding between the casing and formation. A sonic tool detects the bond by transmitting acoustic waves and measuring the amplitude of reflected waves, with lower amplitudes indicating better cement bonding. CBLs are used to detect cement bonding, which is important for supporting the casing, preventing fluid leaks, and isolating zones. Interpreters look for intervals of continuous cement bonding indicated by amplitudes below thresholds like 10 mV over a minimum distance.
The document discusses workover jobs, which refer to interventions done on oil and gas wells to repair downhole equipment and address reservoir issues affecting production. Workovers are necessary when mechanical failures occur or reservoir conditions change. Common reasons for workovers include replacing damaged equipment, fixing casing issues, removing stuck tools, and addressing natural reservoir damage or depletion that reduces productivity. Workovers can involve complex operations like milling packers, fishing operations, and zone recompletions to restore or boost well production.
Brand, Branding and Marketing for Protection Services ProfessionalsLarry Snow
This document discusses branding, marketing, and using social media to establish a brand. It defines a brand as a company's core values and personality. Branding involves activities to get the brand known in the marketplace, like social media marketing, blogging, and communication. Consistency across channels and representing the brand through interactions are important. Marketing involves setting goals, having a strategy, and measuring success through analytics and engagement. The document recommends using social media as a tool to extend the brand by connecting with followers, sharing relevant content, and managing the brand presence across channels.
21 nov ansys meshing - tomas jarneholt ansys swedenAndersANSYS
This document discusses how to speed up the meshing process in ANSYS Meshing by using techniques like simplifying geometry and using appropriate mesh controls. It also explains how to generate hex-dominant and hybrid meshes in ANSYS Meshing which can improve simulation accuracy and solve times compared to pure tetrahedral meshes. The document provides guidance on using ANSYS Meshing tools to create different mesh element types for various applications.
This document provides an overview of setting up co-simulation between ANSYS Mechanical and ANSYS Fluent using System Coupling. It discusses the necessary setup steps in Mechanical including analysis settings, fluid-solid interfaces, and output controls. It also covers the Fluent setup, including defining dynamic mesh zones, solution stabilization options, and notes on fluid compressibility. Finally, it addresses the System Coupling setup for defining data transfers and solution controls between the two solvers.
Coronary artery disease results from the development of atherosclerosis, where plaque builds up in the coronary arteries, reducing blood flow to the heart. Risk factors include elevated cholesterol, smoking, hypertension, diabetes, and family history. Diagnosis involves tests like electrocardiograms, stress tests, and imaging of the arteries. Treatment options include lifestyle changes, medications, angioplasty and stenting, atherectomy, and coronary artery bypass grafting. Nursing care focuses on monitoring for complications, educating on risk factor management, and supporting recovery.
overview on cardioplegia by Dr. Idit AvrahamiIdit Avrahami
This document discusses various cardiovascular diseases and surgical procedures used to treat them. It covers topics like heart failure, valvular heart disease, coronary artery disease, angioplasty, stents, vulnerable plaques, total occlusions, heart valve disorders, heart-lung machines, coronary artery bypass grafting, heart valve replacement and repair, and minimally invasive cardiac procedures. Diagrams are provided to illustrate heart anatomy and surgical techniques like valve replacement and coronary bypass grafting.
Numerical simulation of blood flow in flexible arteries using Fluid-Structure...Mostafa Ghadamyari
We'll model and simulate a simple artery using pressure-based and velocity-based inlet profiles by Adina systems, Comsol Multiphysics, Ansys CFX & structural coupling and Ansys Fluent & structural coupling.
The SlideShare 101 is a quick start guide if you want to walk through the main features that the platform offers. This will keep getting updated as new features are launched.
The SlideShare 101 replaces the earlier "SlideShare Quick Tour".
1. Fluid and Structure Tango in
Biomedical Research
Idit Avrahami, Afeka
ISMBE, I.Avrahami, Afeka
2. Fluid-Structure Interaction (FSI)
The unknown motion of the structure
is a BC for the flow, and vice versa
2
ISMBE, I.Avrahami, Afeka
3. Fluid-Structure Interaction (FSI)
1. Separate the problem to:
– structural domain (S)
– fluid domain (F)
2. Solve each domain separately
3. The interactions occurs along the
interfaces
3
ISMBE, I.Avrahami, Afeka
4. Governing Equations
For the fluid domain For the solid domain
∇⋅U = 0
DU && &
MU + CU + KU = R
ρ = −∇p + μ∇ 2 U
Dt
For moving boundaries
U = u f − ug
Interactions at the interfaces
Vf = Us
n ⋅ τ f = n ⋅ τs
4
ISMBE, I.Avrahami, Afeka
5. Numerical Methods
for solving the PDE
Meshing:
Divide each domain into elements
Discretization:
Approximate the PDE into a set of
algebraic equations (FVM/ FEM)
Moving Mesh in the fluid domain:
ALE (Arbitrary Lagrangian Eulerian )
approach is used to adjust the mesh to
the boundary motion Afeka
ISMBE, I.Avrahami,
5
6. Impedance Pump
based on resonance wave dynamics
Flexible graft Pincher
outflow Fluid
Impedance mismatch
(anastomosis)
6
ISMBE, I.Avrahami, Afeka
7. Pressure waves in Elastic Tube
A local periodic pressure imposed in an
elastic tube produces pressure waves that
travel along the tube in the wave speed of:
Eh
C=
ρd
7
ISMBE, I.Avrahami, Afeka
8. Wave Reflection
• A local excitation in a specific
frequency produces periodic
waves in the domain
• The waves travel along the
domain and reflected by the
reflection site
• The reflected waves are
combined with the traveling
waves
• At specific frequency (natural
freq. and its harmonics) the
reflected waves are added to
the traveling waves and the
waves are enhanced – this is
resonance
8
ISMBE, I.Avrahami, Afeka
12. Numerical Model
Full fixation Full fixation
Imposed harmonic Stress free
dY=dZ=0 dY=dZ=0
motion
Y Fluid-structure interface,
Contact surface no slip conditions
Z
Stress- Stress-
Axisymmetric
free BC free BC
BC
ISMBE, I.Avrahami, Afeka
19. Active Bypass Graft
Using resonance wave pumping
Impedance
pump t
G ra f
y Stenosis
ar ter
nar y
Coro
19
ISMBE, I.Avrahami, Afeka
(Avrahami & Gharib, 2005, BMES)
20. The Numerical Model
Pincher
3D model based on
physiological geometry
Dacron
Graft
Artery
φ 2 mm Anastomosis
450
90% stenosis
(Avrahami & Gharib, 2005, BMES)
ISMBE, I.Avrahami, Afeka
20
21. Resonance Wave Pumping
• Maximal flow is found at natural frequency
150 5E 10
-
Bulk flow
140
Natural
4. 5E 10
-
Dacron Graft
130
D=3mm
4E 10
-
frequency
120 3. 5E 10
-
L= 12 cm
FR (ml/min)
110 3E 10
-
100 2. 5E 10
-
Duty-cycle=50%
90 2E 10
-
80 1. 5E 10
-
Pinch amp =20%
70 1E 10
-
=>
60 5E 11
-
frequency=100 Hz
50 0
25 50 75 100 125 150
Frequency (Hz)
21
ISMBE, I.Avrahami, Afeka
(Avrahami & Gharib, 2005, BMES)
22. Wall Shear Stress at the Anastomosis
without pump
with pump
22
ISMBE, I.Avrahami, Afeka
(Avrahami & Gharib, 2005, BMES)
24. Additional Support Pump
pump
On Cavo-pulmonary Intra - Aortic support
connection support for Pump
Fontan procedure
(Loumes et al., 2008)
(Avrahami et al., 2006) 24
ISMBE, I.Avrahami, Afeka
26. Acknowledgments
• Prof. Mory Gharib, Caltech
• Dr. Laurence Loumes, McGill University
• Dr. Derek Rinderknecht
• Dr. Anna Hickerson
• Division of Materials Technology, NTU,
Singapore
• The Joseph Drown Foundation
26
ISMBE, I.Avrahami, Afeka
27. References
• Avrahami I. and Gharib M. (2008), "Computational
Studies of Resonance Wave Pumping in Compliant
Tubes”, Journal of Fluid mechanics, Vol. 608: 139-160.
• Loumes, L., I. Avrahami and M. Gharib (2008), "Resonant
pumping in a multilayer impedance pump." Physics of
Fluids, Vol. 20(2)
• Avrahami, I., L. Loumes and M. Gharib (2006).
"Numerical investigation of the fluid and structure
dynamics in models of impedance pump." Journal of
Biomechanics 39: 438-400.
27
ISMBE, I.Avrahami, Afeka