Students, faculty, researchers and engineers from fire safety programs around the world are invited to join a competition to predict the burning behavior of a Balsam Fir Christmas Tree. The highest individual and highest group scores - i.e., the average scores of all submissions from a single research team or program (min. 3 team members) - will be announced to all competition participants

The top two research teams (from a university or research institution) with the highest average group scores will also earn the coveted Golden and Silver Pinecone Awards. For the first time in many years (after dominance by the University of Queensland, UQ) the 2021 competition had a new winner: Korea University. In second place (so very close behind) was Ghent University.

The complete Invitation to participate is available PDF iconHERE (PDF).

COMPETITION TREE INFORMATION:three christmas trees

Species: Balsam Fir (3x, pictured right)
Weight: 10.9 kg to 11.1 kg
Height: 191 cm +/- 2 cm

STORAGE: Trees will be kept, unwatered, for 17 days in laboratory storage at approximately 50% relative humidity and 18°C.

IGNITION: A 6 cm diameter pan filled with 40 mL of heptane will be placed below the lowest branches of the tree, approximately 15 cm away from the outermost edge of the tree. Ignition (time, t = 0 s) will be defined as the earliest time at which calculated HRR exceeds 50 kW.

Note: this procedure moves the ignition source farther away from the center of the tree as compared to previous competitions (i.e., 2020 and earlier). Experimental results and the best predicted HRR curves from the 2021 Competition trees are shown at right and in Fig. 3 of the Invitation to Participate [link to PDF].

DATA: Christmas tree mass loss rate will be measured continuously at 1 Hz using a mass balance with a 0.1 g precision. If possible, cone calorimeter measurements will be performed to determine a representative heat of combustion, ΔHc, for each tree. If not, a constant value will be assumed – ΔHc = 17.7 kJ/g [Mell et al. 2009] – to convert this to HRR.

Uncertainties represent one standard deviation of height and weight measurements of each of the three individual competition trees.

HOW TO PARTICIPATE: Generating and submitting your predictions

This year, the submission (and generation of) predicted heat release rate (HRR) curves will once again be made possible by visiting https://pages.nist.gov/christmas_tree_fire_safety/. Here, you can use a custom-made app that allows you to ‘build’ (and submit) your own fire by adjusting just four parameters that define:

  • Fire Growth Rate
  • Peak Heat Release Rate (Peak HRR)
  • Duration of Steady Burning
  • Fire Decay

In this app, after you click submit, an email will be generated that contains the four parameters defining your HRR curve. In this email, please remember to add your name, email and lab affiliation if you wish to receive credit (and final competition results) and CLICK SEND so that we receive your submission.

If you prefer the old system – submitting HRR predictions in massive spreadsheets or .txt files – you may submit those files directly to TreeHRR@nist.gov. These prediction files should be formatted in two columns with a 1 Hz resolution in the format: [time (s) | HRR (kW)].

The 2022 event will be livestreamed here: https://umd.zoom.us/j/7239055335

THE SCORING SYSTEM
Data table from 2019 Christmas tree fire burn.

The burn tests will be repeated in triplicate and your predictions will be scored with respect to the average and standard deviations (with explicit considerations for measurement uncertainty) of experimentally measured burning behavior (i.e., peak HRR, time to peak, fire growth time and duration, and total energy release).

Points (100 possible) will be awarded in 5 categories as listed below. Our scoring system will give up to 20 points for each category so long as the predicted values are within two standard deviations considering the calculated uncertainties. 

Description

Uncertainty calculated as:

Peak Heat Release Rate

Propagation of error including uncertainty in time-resolved balance reading and
heat of combustion

Total Energy Release

Propagation of error including uncertainty in time-resolved balance reading and
heat of combustion  

Time to Peak Heat Release Rate

Standard deviation of time to peak HRR values measured in each of the 3 repeated tests

Duration in which HRR exceeds 80% of peak HRR

In each test, a lower and upper estimate of the duration of burning in which HRR exceeds 80% of peak HRR can be made based on the uncertainty in measured HRR. These two values are shown graphically in Fig. 1.

Uncertainty in 80% duration is thus calculated as the standard deviation of all 6 of these values measured from each of the 3 repeated tests.

Duration in which HRR exceeds 50% of peak HRR

Calculated identically as the uncertainty in 80% duration

 

QUESTIONS?  Please contact demo leaders,  Dr. Isaac Leventon (leventon@umd.edu).

Acknowledgements:
Dr. Leventon would like to thank Dr. Anthony Hamins of NIST for his thoughtful comments and helpful suggestions regarding relevant uncertainty analysis for the scoring of this event.
 


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