CAD/PAD Laser Ignitability Programs at the Indian Head Division, - - PowerPoint PPT Presentation

CAD/PAD Laser Ignitability Programs at the Indian Head Division, Naval Surface Warfare Center

• Mr. Tom Blachowski
• Mr. Travis Thom

Indian Head Division Naval Surface Warfare Center 2010 SAFE – Europe 30 - 31 March 2010

Overview

Two laser ignitability programs will be discussed

• NACES USRM (MK123 Mod 0/MK124 Mod 0) Effort
• U. S. Navy – NACES (Navy Common Aircrew Ejection Seat)

USRM (Underseat Rocket Motor) Evaluate laser ignitability characteristics of USRM propellents

• ACES-II Rocket Catapult Effort

U.S. Air Force – ACES-II (Advanced Concept Ejection Seat) New alternative propellent development effort IHDIV, NSWC Current Capability to conduct other laser ignitability efforts

System Function

NACES Ejection Seat Test – F-14 Configuration – 15 Sep 1989 – NAWC CL

System Function

MK123 Mod 0 / MK124 Mod 0 Underseat Rocket Motor

NACES Ejection Seat

Laser Ignitability Test Approach

For all IHDIV, NSWC Laser Ignitability efforts, a consistent approach test methodology has been adopted

• A Carbon Dioxide (CO ) laser is utilized to supply a uniform heat input

to the energetic material under test

• For the IHDIV test methodology, four differing laser input power levels are

established and then, by varying the laser input pulse duration, assessments

• f the Time to First Light and the 50% Ignitability Thresholds are completed
• The “pass/fail” criteria for the 50% Ignitability Thresholds are a

determined if a “Sustained” combustion or an “Unsustained” combustion reaction is apparent at the completion of the laser pulse

2

NACES Laser Ignitability Test Program

• The primary objective of the NACES USRM effort was to evaluate

any potential differences between the laser ignition thresholds for KU and Mechanite 19 double base propellents at ambient and at cold temperatures.

• Specifically, this evaluation includes comparing both the 50% Ignition

Threshold and the Time to First Light (or Ignition Delay) parameters at ambient and cold temperatures for the two propellents.

• All tests were conducted at atmospheric pressure.
• Cold temperature for this test series was defined as conditioning each

sample to -75 F (-60 C) in the dewar and conducting the specific laser functional test within 15 seconds of the dewar and sample being removed from the chamber.

NACES Laser Ignitability Test Program

Dewar Cover Dewar

Sample Holder

Dewar Cover Dewar

Sample Holder

NACES Laser Ignitability Test Results

Example of a “Go” Test Result

Sustained Combustion Unsustained Combustion

Example of a “No Go” Test Result

The spatial power distribution from the laser was not uniform as evident in the “No Go”

• sample. However, this aspect was consistent throughout this test program.

NACES Laser Ignitability Test Results

Time to First Light vs Laser Flux 10 100 10 100 1000 Laser Flux (W/cm^2) Time to First Light (ms)

Mechanite 19 (70°F) Mechanite 19 (-75°F) KU (70°F) KU (-75°F)

NACES Laser Ignitability Test Results

Energy to First Light vs Laser Flux 1 10 10 100 1000 Laser Flux (W/cm^2) Energy to First Light (J/cm^2)

Mechanite 19 (70°F) Mechanite 19 (-75°F) KU (70°F) KU (-75°F)

NACES Laser Ignitability Test Results

50% Ignition vs Laser Flux 100 1000 10 100 1000 Laser Flux (W/cm^2) 50% Ignition (ms)

Mechanite 19 (70°F) Mechanite 19 (-75°F) KU (70°F) KU (-75°F)

NACES Laser Ignitability Test Results

50% Ignition Energy vs Laser Flux

10 100 10 100 1000 Laser Flux (W/cm^2) 50% Ignition Energy (J/cm^2)

Mechanite 19 (70°F) Mechanite 19 (-75°F) KU (70°F) KU (-75°F)

NACES Laser Ignitability Test Results

• As expected, both the KU and the Mechanite 19 double base propellents

exhibited required significantly increased laser input power levels at low temperature to achieve sustained combustion.

• And as expected, both the KU and the Mechanite 19 double base

propellents demonstrated significantly longer reaction times at low temperature than the reaction times at ambient temperature. Both propellents experienced “quenching” events when tested at -75 F (-60 C) temperatures. “Quenching” is defined as a single test result where the input parameters (laser input power and pulse duration) resulted in a “Sustained Combustion” result; however, when the flame front reached the top of the brass sample holder, the reaction was halted.

NACES Laser Ignitability Test Results

Ash Unburned propellant Brass sample holder Ash Unburned propellant Brass sample holder

Example of a “Quenched” Test Result

NACES Laser Ignitability Test Results

Sample Quenching Events

KU Propellent Mechanite 19 Propellent 10W

• f 8

None of 9 20W

• f 10

None of 10 30W of 10 None of 9 40W of 10 of 9

NACES Laser Ignitability Test Summary

• For both the Mechanite 19 and the KU double base propellents,

significantly higher laser input levels were required to achieve sustained combustion and the Time to First Light (Ignition Delay) times were significantly longer at cold temperature that at ambient temperature

• The Mechanite 19 propellent results exhibited higher standard

deviations than the standard deviation of the KU propellent test results

• The propellent “Quenching” event was unexpected and it has been

recommended that further investigation into this event be conducted

ACES-II System Operation

ACES-II Ejection Seat F-16 Thunderbird Ejection 14 Sep 03 Cockpit Video Pilot was not seriously injured

ACES–II System Operation

Video of CKU-5C/A Test – F-15, 600KEAS, HMTF – 10 Jul 04

ACES-II System Test Operation

CKU-5C/A Rocket Catapult Test – HMTF 18 June 2009

ACES-II System Test Operation

CKU-5C/A Rocket Catapult Test – HMTF 18 June 2009

ACES-II System Components

ACES-II Ejection Seat A - Advanced C - Concept E - Ejection S - Seat

IHDIV, NSWC manufactured IHDIV, NSWC manufactured

ACES-II Ejection Seat currently in use on USAF A-10, F-15, F-16, B-1, & B-2 aircraft

ACES-II System Function

ACES-II Ejection Seat CKU-5C/A Rocket Catapult

ACES-II System Function

CCU-22B/A Impulse Cartridge Installed in the CKU-5C/A

• Gas Inlet at Breech Actuates

CCU-22B/A Impulse Cartridge

• Dual Firing Pins and Primers
• BKNO Charge
• Composite Propellant Grain

produces High Pressure

• Internal Locking Mechanism

releases Catapult Tubes

• Catapult Extends Lifting Seat

from Cockpit

3

ACES-II System Function

• Catapult Gas Initiates Auxiliary Igniter
• BKNO and Propellant Chips in

High Density Polyethylene Cup

• Rocket Motor Propellant Grain

ignites and Produces Sustaining thrust

• Catapult Booster Tube Separates and

Remains in the Aircraft

3

Nozzles Rocket Thrust Exhaust

CKU-5C/A Catapult Effort

Primary Objective of the Laser Ignitability effort for the ACES-II CKU-5C/A Rocket Catapult Alternative Propellent was:

• To establish the 50% Ignition Threshold and Time to First Light

values for each differing composite (HTPB) propellent configuration These data points provided the system design engineers a rapid, low-cost preliminary evaluation to various differing HTPB propellent configurations

CKU-5C/A Laser Ignitability Test Results

Laser Spot Laser Spot

Example of CKU-5C/A Propellent “Sustained” Reaction - GO Example of CKU-5C/A Propellent “Unsustained” Reaction – NO GO

CKU-5C/A Laser Ignitability Test Results

Example of CKU-5C/A Propellent – “Sustained” Combustion

CKU-5C/A Laser Ignitability Test Results

CKU-5 Laser Ignition

y = 7757.6x-1.0801 R2 = 0.9989

1 10 100 100 1000 Laser Power (watts/cm2) Time to 50% Ignition (msec)

0020 Baseline

Example of Typical Results of CKU-5C/A Propellent Testing

CKU-5C/A Laser Ignitability Test Summary

Summary: Over 10 alternative propellent formulations were evaluated utilizing this laser ignitability methodology (800+ tests). One of these propellent batches (IHDIV S/N -0020) very nearly matched the Time to 50% Ignition performance of the older CTPB propellent Therefore, the Sensitivity (or the 50% Ignition Threshold) and the Reactivity (Time to First Light or Ignition Delay) of this new propellent batch very nearly matched the performance of the older CTPB propellent Based on this data, in addition to other elements, sub-components and full-scale CKU-5C/A Rocket Catapults, utilizing the new HTPB propellent were fabricated and tested at IHDIV, NSWC All of these test results, both sub-component and full-scale, demonstrated that the selected HTPB propellent was capable of achieving system requirements

Upgraded Capability

200W CO2 Laser Test Chamber 200W CO2 Laser Test Chamber

New Laser New Test Cell

Conclusions

• The IHDIV, NSWC Laser Ignition capability has successfully

contributed to a series of design programs and on-going investigations

• NACES USRM double base propellents (KU and Mechanite 19)

exhibited consistent laser ignitability characteristics at ambient and at low temperature – “Quenching” effect requires additional investigation

• ACES-II CKU-5C/A Rocket Catapult, utilizing new HTPB propellent,

successfully introduced into fleet

• The IHDIV, NWSC Laser Ignition capability has been upgraded

and is being continually utilized to support a wide range of CAD/PAD efforts