Austin FrazerEileen KobalAna Maria MaldonadoMarie Rohrbaugh

Moog Gas EvacuationSystems Design Review

The Team

Austin Frazer Role: Lead Engineer - Analysis Major: Mechanical Engineering

Eileen Kobal Role: Lead Engineer – Mixtures

of Gas Fluids Major: Chemical Engineering

Ana Maria Maldonado Role: Team Manager Major: Industrial Engineering

Marie Rohrbaugh Role: Project Manager Major: Mechanical Engineering

Problem Statement

To mass spectrometer

UUT

High pressure helium

High pressure helium

Fixturing/leakage similar to other side

Fixtures interface between AGT can and UUT

Fixture leakageUUT leakage

Current Procedure

Our process needs to minimize leakage from fixtures

Oring Leakage Diagram

VOC to

VOE customer

rating

Mate with the

current softwar

e system

No extra procedur

e is required to make

the system

run

The system starts when

the test starts

Nitrogen

moves when the

system is

told to start

<5 sec between start of test

and equilibri

um

Reduce the

leakage into the can to 1% of

original value

No adjustment made to

original design

<100scc

/min of

Nitroge

n used

Maintenance plans

provided

Training

materials provided

cost of system is

<$10,000

time betwee

n mainten

ance cycles is

>30 days

FMEA performed

training

takes

<30 min

provide accurate test data 10 * * *

Preserve Vacuum 1 *

Reduce delay caused by false failures 7 * *

minimize increased cycle time 8 * * * * * *

user safety 12 * *

operator understands process 3 * * *

system is controlled transparently by the existing software 9 * *

minimize cost by balancing initial cost, maintenance cost, and consumable

materials6 * * * * * *

sturdy and robust system 11 * *

maximize time between maintenance cycles 4 * *

maintenance plans 5 *

maintenance can be accomplished with minimal money and time 2 * * *

Voice of the Engineer

Design Constraints

Safety Contamination

Class 10,000 clean room. All products should comply to a strict cleanliness

certification Existing Fixture

Cannot modify inside of can Must be attachable to can

Gas Flow Nitrogen gas at 120psia available Vacuum at 1psia available

Function Tree

Concept Generation

Pugh Diagram- Move/ Evacuate the Gas

Comparison Concept A B C D

small centrifugal pump to draw

out test gas

heating / cooling a

reservoir of inert gas to

draw out test gas

additional mass spectrometer at the vent draws

out test gassmall vacuum

pump

alternating drawing down

the test gas and pumping with a

flush gasCriteria Weight

Application elsewhere at Moog 1 0 -1 1 0 0Availability of resources 7 0 -7 -7 0 0Contamination possibility 9 0 0 0 0 0Cost 8 0 -8 -8 0 -8Durability (everyday use) 7 0 -7 0 0 0Effectiveness 9 0 -9 9 9 9Fits timeline 10 0 -10 0 0 0Long term benefits 5 0 0 0 0 0Maintainable 5 0 -5 0 0 0Meets space limitations 8 0 0 0 0 0Safety 10 0 0 0 0 0Works transparently with current system 9 0 0 -9 0 0 0 -47 -14 9 1

Pugh Diagram- Access the Gas

Comparison

Concept A B C

larger cavity for gas collection

modify vent geometry

fill vent with a viscous fluid to

prevent He from entering

have a different o-ring material so that the He

doesn't go through

Criteria Weight

Application elsewhere at Moog 1 0 0 -1 1

Availability of resources 7 0 0 -7 -7

Contamination possibility 9 0 0 -9 -9

Cost 7 0 -7 7 -7

Durability (everyday use) 7 0 0 -7 0

Effectiveness 9 0 9 -9 0

Fits timeline 10 0 0 0 0

Long term benefits 5 0 0 -5 0

Maintainable 5 0 0 -5 5

Meets space limitations 8 0 0 8 8

Safety 10 0 0 10 0

Works transparently with current system 9 0 0 -9 9

0 2 -27 0

Block Diagram

Flexline to Nitrogen Source

Flexline to Vacuum Source

To vent

To large o-ring X2

Relief Valve

AN Fitting

2-way 2-position solonoid valve

Flexline to Nitrogen Source

Flexline to Vacuum Source

To vent

To large o-ring X2

Relief Valve 3-way 2-

position solonoid valve

AN Fitting

2-way 2-position solonoid valve

Analysis Performed – Simscape Model

Analysis Performed – Simscape Model

Case 1)

Analysis Performed – Simscape Model

Case 2)

Analysis Performed – Simscape Parameters

Model Orings as Orifices

 1  2 𝐾=𝜌

2𝐶𝑑2 𝐴2

𝛿𝑃=𝑃1−𝑃2

L = Approximate leak rate of the seal, std. cc/sec.F = Permeability rate of the gas through the elastomer at the anticipated temperature, std. cc cm/cm2 sec bar. (example: Butyl's permeability at 77oF with Acetylene is 1.26 x 10-8 std. cc cm/cm2 sec bar)D = Inside diameter of the O-ring, inches.P = Pressure differential across the seal, lb/in2 .Q = Factor depending on the percent compression and whether the O-ring is lubricated or dry (from figure 3 below)S = Percent compression on the O-ring cross section expressed as a decimal (i.e. for 20% compression, S = 0.20)

Diffusion

Diffusion Coefficient for 2

gasses

Diffusion Flux: Movement due to

Diffusion across an area

Gantt Diagram

Risk Assessment

Questions??