FINAL PRESENTATION

P13681

2

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

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Concept Summary

To mass spectrometer

Valve

High pressure helium

High pressure helium

Fixturing/leakage similar to other side

Fixtures interface between AGT can and valve

Fixture leakageValve leakage

Leakage from valve

Leakage from Fixture

Leakage from room through lid and baseplate

Moog’s Problem Statement:

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Concept Summary ContinuedMoog’s current means of fixture leakage reduction: Vented Double O-ring

3000 psi

Valve

0 psi (Vacuum)

• Vent open to ambient. Leakage past 1st O-Ring is meant to dissipate out of can

• MSD team is able to modify vent conditions

5

Concept Summary Continued

• Moog already has “constant N2 flow” subsystem implemented on bottom large O-ring

• Similar subsystem could be applied to top large O-ring

• This was listed as lower priority

Constant N2 flow during test

Moog’s current means of fixture leakage reduction: Large O-rings

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Customer Specifications and Requirements

Ran

king

Voice of the Customer

to Voice of the

EngineerNumbers represent how well the engineering specification meets the customer requirement .

The Ranking describes how important the customer need is.

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Project Overview

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Simulink Model• System was modeled in Simulink to help select a concept

• Only vented double O-ring was modeled. Not large O-rings• Model was built with a perfectly mixed assumption. This would prove to be a

poor assumption• Results of the Simulation indicated that a pulse-purge vent condition

would most drastically reduce the fixture leakage. This was the basis for the system design of MSD I

0 50 100 150 200 250 300 350 4000

0.2

0.4

0.6

0.8

1x 10

-11

Time (seconds)

He

Can

Lea

kage

(cc

/s)

Volumetric Flow Rate of Helium into the Can Over Time

Case 3

Case 1 (Baseline)

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Initial Project Design – End of MSD I

Permanent Subsystem Required:• Modification of baseplate• Robust Labview programming by Moog

supplier• System was required to operate

independent of operator input• Multiple circle seal valves• Robust and space - efficient mounting of all

required components• Hardlines capable of safely handling high

pressures

Cost: Approximately $7,500 per AGT

The initial design (per the detailed design review) was intended to be a permanent system. Due to budget cuts this was eliminated as a viable concept Design accounts for large O-ring and

vented double O-ring leakage

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Initial Project Design Continued

High Pressure Inlet

All vents connected to one system

Modifications to baseplate necessary

Access port to Vent

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Initial Project Design - Continued

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Actual System Design – Portable System• Due to budget cuts, a portable “proof of concept” system was

created to test the validity of the pulse purge vented double O-ring

• Most design criteria from MSD I remained intact. Changes include• Valves, regulators, electrical components donated by Moog• All parts machined and assembled by the MSD team• Electrical subsystem to control valve(s) to be designed/implemented

by MSD team• Operator input into system OK

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Actual System Design - Schematic

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Actual Project Design – Portable System

Tube represents valve. Typically the Fixture system is on both the inlet and outlet of the valve.

High Pressure Helium into Fixture System

Vented Helium

Seals have two o-rings with a vent between. Gas moves freely between the seals.

Helium Leakage from Fixture

Welded to minimize leakage

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Bill of Materials

Total cost ~$1000

Total cost after donated/borrowed items ~$40

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System Architecture

Flexline goes to next slide

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System Architecture Continued

Helium InletVent Port

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Results• 4 hours of continuous leakage data was acquired under

varying vent conditions. Sample plot is given below:

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Results Continued

0 100 200 300 400 500 600 700 800-5

-4

-3

-2

-1

0

1

2

3

4

5x 10

-6 Constant 30psi Nitrogen

He Pressure (psi)

Cor

rect

ed L

eaka

ge (s

cc/s

ec)

0 100 200 300 400 500 600 700 800-1

-0.5

0

0.5

1

1.5

2

2.5

3x 10

-5

He Pressure (psi)

Co

rre

cte

d L

ea

kag

e (

scc/

sec)

Pulse-Purge

30psi N2

Low P N2

0 100 200 300 400 500 600 700 800-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5x 10

-7 Constant Vacuum

He Pressure (psi)

Co

rre

cte

d L

ea

kag

e (

scc/

sec)

Duty cycle varies within this plot. No correlation between duty cycle and leakage rate*

Proves to increase fixture leakage (as expected)

*It is concluded that the N2 pulse actually pushes the Helium out of the vent. Uniform mixing does not occur

Not strong enough correlation to draw conclusions (see order of magnitude)

Analysis of the test data produces the following plots:

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Results Continued

Constant N2 flow around large O-rings significantly reduces fixture leakage

1 sec of pressure followed by 50 sec of vacuum

Cycled 14 times 14 peaks

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Conclusions• Proof-of-concept design was successfully designed and

assembled. Reliable test data was collected• Test data indicates that pulsing/purging the vented double

O-ring volume does not reduce fixture leakage adequately• Test data indicates that constant flow of N2 past the lower

large O-ring significantly reduces leakage results• A constant flow through the vent is expected to significantly reduce

fixture leakage

• Project output is consistent with current Moog priorities• Data was collected and the concept was tested. Relatively few un-

returnable company resources were used. A conclusive answer has been acquired

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Our Recommendation• Do not pursue pulse purge vent condition

• If modifying selected fixturing was a possibility, allowing a constant flow through the vent is expected to significantly reduce fixture leakage

• Implement the constant N2 flow system on the upper large O-ring• Designs have already been completed for the modification of the can

and manufacturing of addition required components

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MSD II Schedule

We finished on time!!!

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Acknowledgements• Robert Bauer & Moog Space and Defense Group• Michael Zona• Dr. Jason Koldziej• Dr. Karuna Koppula• Dr. Elizabeth DeBartolo• Prof. John Wellin

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QUESTIONS?

Thank you for coming!