TIME_SHRINK_FACTOR in FDS Rosalie Wills, P.E. Koffel Associates, - - PowerPoint PPT Presentation

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TIME_SHRINK_FACTOR in FDS Rosalie Wills, P.E. Koffel Associates, - - PowerPoint PPT Presentation

Nov 19, 2022 24 likes •252 views

Effect and Appropriate Use of TIME_SHRINK_FACTOR in FDS Rosalie Wills, P.E. Koffel Associates, Inc. 8815 Centre Park Drive Columbia, MD, 21045, USA e-mail: rwills@koffel.com TIME_SHRINK_FACTOR Reduces the time necessary to transfer heat

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SLIDE 1

Effect and Appropriate Use of TIME_SHRINK_FACTOR in FDS

Rosalie Wills, P.E.

Koffel Associates, Inc. 8815 Centre Park Drive Columbia, MD, 21045, USA e-mail: rwills@koffel.com

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SLIDE 2

TIME_SHRINK_FACTOR

  • Reduces the time necessary to transfer

heat to surfaces by reducing the specific heat of the materials by that factor

&TIME TIME_SHRINK_FACTOR=10. /

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SLIDE 3

TIME_SHRINK_FACTOR

  • Reduces the device activation time and

simulation time by the same factor

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SLIDE 4

FDS and Fire Protection Engineering Design

  • Atrium Smoke Control
  • Building Fire Exposure
  • Performance Based Approach
  • Code Modification
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SLIDE 5

Defined Inputs

  • Mesh and Boundaries
  • Fuel Properties
  • Obstruction Properties
  • Concrete and Gypsum
  • Room Geometry
  • Fire Location (center of

floor)

  • Fire Size (500 kW)
  • Natural Makeup air

and Exhaust

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SLIDE 6

Defined Outputs

  • Slice files
  • Temperature, Visibility, Velocity
  • Thermocouples
  • Gas temperature of smoke layer
  • Gas temperature near wall
  • Wall Temperature
  • Upper and Lower
  • Beam detector
  • Boundary Quantity
  • Incident heat flux
  • Wall temperature
  • Volume and Mass Flow above

Fire

  • Smoke Layer Height
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SLIDE 7

Simulation Matrix

Scenario Heat Release Rate Time Shrink Factor Steady Growth None 2 5 10 1 X X 2 X X 3 X X 4 X X 5 X X 6 X X 7 X X 8 X X

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SLIDE 8

Simulation Run Time Results

Scenario Simulation Time TSF Run Time Reduced 1 NA NA 2 2 1.9 3 5 4.7 4 10 9.2 5 NA NA 6 2 2.1 7 5 5 8 10 10

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SLIDE 9

Lower Wall Temperature (Steady)

10 20 30 40 50 500 1000 1500 2000 2500 3000 Temp (C) Time (sec) 1 2 3 4

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SLIDE 10

Lower Wall Temperature (Growth)

10 20 30 40 50 500 1000 1500 2000 2500 3000 Temp (C) Time (sec) 5 6 7 8

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SLIDE 11

Heat Release Rate (Steady)

100 200 300 400 500 600 700 500 1000 1500 2000 2500 3000 Heat Release Rate (kW) Time (sec) 1 2 3 4

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SLIDE 12

Heat Release Rate (Steady)

100 200 300 400 500 600 500 600 700 800 900 1000 Heat Release Rate (kW) Time (sec) 1 2 3 4

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SLIDE 13

Heat Release Rate (Growth)

100 200 300 400 500 600 500 1000 1500 2000 2500 3000 Heat Release Rate (kW) Time (sec) 5 6 7 8

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SLIDE 14

Smoke Layer Temperature (Steady)

10 20 30 40 50 60 70 500 1000 1500 2000 2500 3000 Smoke Layer Temp (C) Time (sec) 1 2 3 4

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SLIDE 15

Smoke Layer Temperature (Growth)

10 20 30 40 50 60 500 1000 1500 2000 2500 3000 Smoke Layer Temp (C) Time (sec) 5 6 7 8

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SLIDE 16

Smoke Layer Height (Steady)

2 4 6 8 10 12 500 1000 1500 2000 2500 3000 Smoke Layer Height (m) Time (sec) 1 2 3 4

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SLIDE 17

Smoke Layer Height (Growth)

2 4 6 8 10 12 500 1000 1500 2000 2500 3000 Smoke Layer Height (m) Time (sec) 1 2 3 4

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SLIDE 18

Upper Wall Temperatures (Steady)

10 20 30 40 50 500 1000 1500 2000 2500 3000 Temp (C) Time (sec) 1 2 3 4

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SLIDE 19

Upper Wall Temperatures (Growth)

5 10 15 20 25 30 35 40 500 1000 1500 2000 2500 3000 Temp (C) Time (sec) 5 6 7 8

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SLIDE 20

Practicing Fire Protection Engineering

  • Atrium Smoke Control
  • Building Fire Exposure
  • Performance Based Approach
  • Code Modification
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SLIDE 21
  • Size of TIME_SHRINK_FACTOR
  • Size of fire
  • Size of Simulation
  • Duration of TIME_SHRINK_FACTOR
  • What results are you interested in?
  • Perform your own test case
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SLIDE 22

THANK YOU