Numerical modelling of the aerial drop of firefighting agents by fixed-wing aircraft. Part I: model development
Document Type: Journal Article
Author(s): J. H. Amorim
Publication Year: 2011

Cataloging Information

  • Aerial Drop Model
  • coniferous forests
  • croplands
  • deciduous forests
  • drop effectiveness
  • droplet flow
  • evergreens
  • fire management
  • fire retardants
  • fire suppression (aerial)
  • firefighting
  • forest fires
  • forest management
  • grasslands
  • statistical analysis
  • wildfires
  • wind
Record Maintained By:
Record Last Modified: October 16, 2019
FRAMES Record Number: 49246
Tall Timbers Record Number: 25583
TTRS Location Status: In-file
TTRS Call Number: Journals - I
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.


The efficiency of the aerial drop of firefighting agents (water and retardants) is extremely dependent on pilot skills in dealing with complex atmospheric conditions, mostly because on-board systems for computer-assisted drops have not yet been used operationally. Hence, numerical modelling tools can be of primary importance for the optimization of firefighting operations and in the testing of new chemical products. The current work addresses the development of the operational Aerial Drop Model. This numerical tool allows a near real-time simulation of aerial drops with fixed-wing aircraft, while covering the fundamental stages of the process. It copes with a wide range of product viscosities, from water to highly thickened long-term retardants. The Aerial Drop Model simulates the continuous stripping of droplets from the liquid jet by the action of Rayleigh-Taylor and Kelvin-Helmholtz instabilities applying the linear stability theory. The subsequent secondary breakup and deformation of the formed droplets due to aerodynamic forces is based on experimental correlations defined in terms of the dimensionless Weber number. Droplet trajectories are computed by applying a Lagrangian approach, in which a dynamical drag module accounts for the effect of deformation. This operational tool provides an improved understanding of the behavior and effectiveness of aerially delivered firefighting liquids.

Online Link(s):
Amorim, J.H. 2011. Numerical modelling of the aerial drop of firefighting agents by fixed-wing aircraft. Part I: Model development. International Journal of Wildland Fire 20(3):384-393.