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This report summarizes the multidisciplinary senior design project conducted on December 21, 2012, focusing on a particle image velocimetry (PIV) experiment aimed at validating CFD models for both healthy and diseased lungs. The Army Medical Research Lab is the primary customer. The senior design team developed hollow lung models and testing apparatus to simulate inhalation and exhalation, monitor flow rates, and control pressure. The specifications include image accuracy, material compatibility with fluid properties, and a LabVIEW program for experiment automation, addressing critical customer needs.
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Systems Level Design Review Multidisciplinary Senior Design 1 Friday, December 21st, 2012 P13051
P13051 – PIV Experiment for Flow Mapping in Lungs • Customers: • Dr. Risa Robinson • Dr. Steven Day • Team Guide: • Michael Antoniades – Chemical Engineering • Team: • Kristin Roberts – Project Manager, ME • Morgan DeLuca – ME • Brad Demarest – EE • Ryan Mark – ME • Jimmy Moore – CE • Jake Snider – ISE
Agenda • Project Background • Customer Needs • Engineering Specifications • Functional Analysis • Concept Generation & Selection • Lung Model • Pump • Pressure Measurement & Control • Feasibility Analysis • Risk Assessment • Project Planning & WBS
Project Background • The Army Medical Research Lab needs to validate their CFD models for healthy and diseased lungs • RIT will perform particle image velocimetry (PIV) on lung models to validate the CFD. • The senior design team will design and develop the lung models and testing apparatus.
What is PIV? • Used for flow visualization and velocity measurements • Fluid is seeded with tiny tracer particles • The particles are illuminated using a laser sheet, and a camera takes pictures of the particles. • Fluid velocity profiles can be obtained by analyzing particle movement from frame to frame.
Key Customer Needs • Create hollow lung model using specified geometry up to the 14th generation • Accommodate various image locations • Simulate inhalation and exhalation • Monitor flow rate and pressure • Control flow at outlets to mimic boundary conditions of CFD model • Accommodate imaging with no distortion • Create LabVIEW Program and procedure to run experiment • Can easily switch between models
Key Engineering Specifications • Image location can be located within ±5mm • Model Reynolds number must be within X% of lung Reynolds number • PIV fluid must match model material index of refraction within ±X. • Models can be switched in less than X hours. • Accuracy of pressure measurement is X. • Match boundary conditions within X%.
Lung Model Concepts – Silicone Block • Positives: • Robust • Easier to prevent distortion • Rapid prototype airspace using PVA • Negatives: • Will be difficult to rapid prototype smaller dimensions in PVA • Possible solution: Scale model up match Reynolds number • Any bubbles in silicone could cause distortion • Possible solution: Use vacuum to reduce bubbles • Cost: • 5 gallon of silicone=$1,719.96 • 1 pound of PVA=$10-20
Lung Model Concepts – Rapid Prototype • Positives: • Can more easily model smaller details and intricacies. • Easier to access specific portions of model since it is not encased in a solid block. • Prototyping all generations should not be a problem • Negatives: • Fragile, especially at higher generation air passages; transporting model comes with the risk of damage. • Would need to construct a container/support system prevent distortion. • Cost: • High – Intricate design with small passageways increases cost to rapid prototype.
Lung Model Feasibility • Silicone Model: • Initial calculations: 18.6% Water, 81.4% Glycerol will match index of refraction for Sylgard-184 • Rapid Prototype Model: • AccuraClearvue • Colorless • Layer Thickness - Horizontal build layers down to 16 microns (0.0006 inches). • Build Resolution - X axis: 600 dpi. Y axis: 300 dpi. Z axis: 1600 dpi. • Cost- $ 1,140
Pump Selection Image Credit: Wikipedia; Info Credit: pumpscout.com
Pump Feasibility • Viscosity • Glycerin/Water mixture that ranges from 82%-75% glycerin • Approximately 500 SSU – 320 SSU • Flow rate • Reynolds number matching – Used approximate fluid properties and average breathing flow rate • Approximately 20-30 gpm • Pressure • Analyzed pressure loss through model using poiseuille flow equation • Approximately 20.8 psi (maximum)
Flow Control • micro valve system (2 or 3 way) • - system will be placed on every outlet where monitoring is required • - valve will be fitted with measuring device in series with model flow • - micro-valves capable of diameters as • small as 1 mm • - cost $5 per unit
Pressure Measurement Pressure Transducer Pros - easy to implement into system - information readily available - data acquisition trivial Cons - not designed for extremely low pressures (accuracy drops dramatically below 5 psi) - very expensive (low pressure high res. $900)
Pressure Measurement Cont. Low Pressure Sensor Pros -very accurate to .01 psi -only $20-40 per unit -compact Cons -pressure range small (-5 to 5 psi) -cumbersome to implement (board required)
Digital Input to Labview • NI USB-6008 • Cost: $169 • Easily interfaces with Labview • High Sample Rate (10k S/s)
Labview Code • Not fully completed • Need all components before testing and construction can occur.
Project Planning • Microsoft Project used to determine slack in tasks as well as critical pathby determining predecessors and estimated duration of tasks.
Roles and Responsibilities • Kristin Roberts – ME, Project Leader • Project Organization • Fluid Mechanics • Ryan Mark - ME • Pressure sensing and Control • Rapid Prototyping • Data Acquisition • Morgan DeLuca – ME • Pump Design • Fluid Mechanics
Roles and Responsibilities cont’d • Jimmy Moore - CE • Camera & Model Positioning • Controls Design • Brad Demarest - EE • Data Acquisition • Prototype Material Choice • Jake Snider - ISE • Project Planning • Labview Design