HEAT RELEASE RATE Federal Aviation Updates · Federal Aviation Administration HEAT RELEASE RATE...

Federal Aviation Administration

HEAT RELEASE RATE

Updates

2015 February Materials Meeting

Huntington Beach, CA

Materials Working Group

Michael Burns, FAA Tech Center

February, 2015

AGENDA

Upper Pilot Burner Hot Surface Igniter

- Review handbook document for use in

today’s OSU’s

HR2 / OSU

- Test Data

- Chapter HR Updates

Next

UPPER PILOT HSI (HOT SURFACE IGNITER)

• FAA Fire Test Handbook Version (OSU)

(Most likely Placed in Supplement Bullet 5.3.8)

• Optional Use (Much like the Drip Pan)

• Reduce variability within OSU heat release

units with regard to the performance of the

upper pilot burner

• Request Task Group Input


-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

1 2 3 4 5 6

Mill

ivo

lts

Lab Code

Voltage Delta's (with HSI)

1 L/min

4 L/min

6 L/min

8 L/min

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1 2 3 4 5 6

(kW

/m2)/

mV

Lab Code

Cal. Factor Delta's (with HSI)

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

1 2 3 4 5 6

Mill

ivo

lts

Lab Code

Baseline mV Delta's (with HSI)

-0.16

-0.14

-0.12

-0.1

-0.08

-0.06

-0.04

-0.02

0

1 2 3 4 5 6W

/cm

2

Lab Code

Upper Corner Uniformity (with HSI)

Upper Left

Upper Right


• It is critical that the upper pilot burner tube is not

moved out of position once set correctly.

• If the tube is inadvertently moved forward (towards

the globars) there is a chance that a large portion of

the upper pilot flames will go out entirely in the

presence of fire retardants whereas when in the

correct position only the flame tiplets will be

impacted while the material is burning off.

• The difference between the two conditions could

have a dramatic effect on the data.


• In the event a material continues to impact the upper

pilot flames even with the burner tube in the correct

position an optional Hot Surface Igniter (HSI) may

be installed.

• Alternatively, the HSI may be installed and used for

all materials tested.

• If this device is installed, the center heat flux density

and 5% uniformity requirement must be verified

subsequent to a Methane gas calibration.


• A 0.125 ± 0.005 inch diameter stainless steel rod 8.0

± 0.0625 inches in length is positioned directly in

the flames of the upper pilot burner.

• The rod is continuously heated by the flamelets

acting as a hot surface igniter to auto-ignite any

upper pilot flames should they go out.

• The distance from the centerline of the burner tube

to the centerline of the HSI rod is 0.75 ± 0.125 inch.


• Two stainless steel support brackets are mounted on

the upper pilot burner tube.

• The brackets are separated 8.0 ± 0.0625 inches from

each other (outer dimension) with one bracket

aligned flush with the closed end of the burner tube.

• Due to forced air flow through the chamber and

convection the upper pilot flames tend to curve

upward.

• To locate the HSI rod in the hottest portion of the

burner flames, the brackets are rotated upward 15 ±

5̊ on each end (Digital Protractor).


• It is not necessary for each bracket to be at the same

angle provided the rod is in the direct flame path

across its entire length.

• Set screws secure the rod and brackets in position.

• The HSI rod must be cleaned or replaced when

showing signs of soot buildup or wear.

• Unless otherwise specified, dimensions are nominal

values in inches.


Upper Pilot Burner HSI Rod and Brackets


HSI Rod and Bracket Installation


HSI / Upper Pilot Burner Operation


Heat Release Rate Test Apparatus

February 2015

HR2 UPDATE

CHAPTER HR UPDATES

• Added “Burr-free holes , internally and externally, but not chamfered”

requirement to:

o Upper pilot burner holes (15)

o Lower Plate holes (8)

o Second Stage Plate holes (120)

• Range for Valid Calibration Factor must be 0.085 +/- 0.010 kW/mV

Removed all references to:

o Calibration Pass/Fail Criteria (5% STDEV): This is due to difficulties in

achieving this criteria now that the calibration factor is so small.

o Calibration Factor Term: (kW/m2)/mv

• Standardized use of sample holder drip pans.

o Required for all testing regardless of whether a material drips or not

o Optional: Permanently mounted to holder or removable

CHAPTER HR UPDATES

• For Stability (Heat Flux and Thermopile) :

o 5% STDEV requirement was lowered to 2% STDEV (5% was too easily

achieved while the system was still observed warming up).

o Added statement that center heat flux and thermopile are calculated

based on moving averages. (60 second moving average and 15 minute

moving average respectively).

Center Heat flux (60 second moving average)

Heat flux gauge millivolt signal that varies less than 2.0% standard deviation

over the last 60 seconds and having a calculated heat flux density that is

within range.

Chamber equilibrium (15 minute moving average)

Thermopile millivolt signal that varies less than 2.0% standard deviation

over the last 15 minutes commencing no sooner than 30 minutes after

turning the power to the globars on.

CHAPTER HR UPDATES

• Standardized Upper/Lower Pilot Gas Flow (Flow Meter Survey)

o Lower Pilot Flow Requirement:

Methane: 120 ± 5 mL/min (via panel mounted flow meter)

Air: 1.0 ± 0.2 L/min (via panel mounted flow meter)

o Upper Pilot Flow Requirement:

Methane: 1.5 ± 0.1 L/min (via HR2 calibration MFM/MFC)

Air: 1.0 ± 0.2 L/min (via panel mounted flow meter)

* All visual references in the document are aids in determining the correct

flame profile but the actual flow settings must be used (Photo’s added).

• Added caution statement that since drip pans are now required, if an electronic

igniter system is in place (lower pilot) it must not come in contact with the

sample holder drip pan when testing.

• Increased tolerance on airflow from 20 +/- 0.5 to 20 +/- 1 SCFM



February 2015

48

56

50

99

85

52 48

51

45

100

84

52

0

20

40

60

80

100

120

Schneller 5596_36 5596_31 950_032 950_060 STD CC Panel

kW/m

2

Material ID

Peak Heat Release Rate

HR2

OSU

3% 1% 2% 4% 4% 4% 5% 3% 3% 1% 4% 1%

% Stdev (Repeatability)



February 2015

46

25 28

50

97

47 47

27 28

51

97

51

0

20

40

60

80

100

120


Seco

nd

s

Material ID

Time to Peak Heat Release Rate (seconds)

HR2

OSU

2% 5% 3% 2% 3% 1% 2% 12% 1% 0% 2% 2%




February 2015

37

47

55

37

31

37

40

52

59

42

33

38

0

10

20

30

40

50

60

70


kW*m

in/m

2

Material ID

2-Minute Total Heat Release

HR2

OSU

2% 3% 1% 6% 0% 4% 4% 1% 4% 3% 1% 2%




February 2015

NEXT

• Assemble larger Focus Group RR comparing

HR2 (1) and Industry OSU’s (13)

• Develop and Distribute Test plan and materials

to participating labs

• Conduct RR Tests

• Reduce / Analyze Data for presenting at June

WG meeting

• Complete the HSI development Project



February 2015

The Seattle Seahawks should:

A. Have given the ball to Marshawn

Lynch?

QUESTIONS?or presenting at June WG meeting



February 2015

The Seattle Seahawks should:

A. Have given the ball to Marshawn

Lynch?

B. Fire the Offensive Coordinator?

QUESTIONS?or presenting at June WG meeting

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