Systems Level Design ReviewMultidisciplinary Senior Design 1Friday, 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 Needs1. Create hollow lung model using specified

geometry up to the 14th generation2. Accommodate various image locations3. Simulate inhalation and exhalation4. Monitor flow rate and pressure5. Control flow at outlets to mimic boundary

conditions of CFD model6. Accommodate imaging with no distortion7. Create LabVIEW Program and procedure

to run experiment8. Can easily switch between models

Key Engineering Specifications1. Image location can be located within

±5mm2. Model Reynolds number must be within

X% of lung Reynolds number3. PIV fluid must match model material

index of refraction within ±X.4. Models can be switched in less than X

hours.5. Accuracy of pressure measurement is X.6. Match boundary conditions within X%.

Functional Analysis

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:▫Accura Clearvue

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 SelectionPump Flow Rates Pressures Comments Cost (3 highest)

Gear pump Acceptable,Up to 30 gpm

Acceptable,Up to 30 psi

Common, bi-rotational, can be self-priming

2

Rotary Vane Acceptable Acceptable Not really used in our application

1

Diaphragm Acceptable Acceptable Create pulsing flow, need air supply, cheaper

1

Lobe Pump Acceptable Acceptable Used in Sanitary applications where fragile solids are used, bi-rotational, may be overly complex

3

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 TransducerPros- 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.

System Overview

Risk AssessmentID Risk Item Effect Cause

Likelihood

Severity

Importance Action to Minimize Risk Owner

1

Long lead time to produce lung model

Cannot assemble test rig Model is sent too late

2 3 6

Verify lead time on rapid prototyping, send out model before spring quarter

2 Design does not meet needsProject Failure, unsatisfied customer

Needs not mapped to correct specifications 2 2 4

System Design Review includes discussion on needs and specs, Customer will be consulted throughout the quarter

3Design not executed to specifications Project Failure

Specifications were out of range 1 2 2

Detailed Design Review will verify the design meets the specs, Specifications will be finalized and approved by customer

4 Project goes over budgetWill not adhere to customer need

Project not accurately budgeted 2 2 4

Provide options of varying cost, determine importance of specifications

5 Lung model is damagedCannot assemble or test project

Material chosen is brittle, cannot withstand forces 1 3 3

Will choose method of manufacturing that produces a stronger, less brittle product

6Scope of pressure measurements is too large Will not meet specs

Too many outlets need to be tested, increased cost 3 2 6

Speak with customer to limit number, Choose cheaper method

7Too much noise in pressure measurements

Cannot get accurate reading of pressure

Output pressure too small 2 1 2

Reduce noise with instrumentation amplifier

8Labview data doesn’t not follow expected relationship

Will not get accurate output values Error in coding 2 2 4

Verify with testing of code with known values

9Pump does not deliver consistent flow rate

Will not be able to supply correct flow rate, will not be steady state Wrong pump chosen 1 2 2

Verify precision of pump flow rate, Test pump before installing in system

Project Planning

•Microsoft Project used to determine slack in tasks as well as critical path by 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

Questions?