Imperial College London

Professor Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Planetary Science
 
 
 
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Contact

 

+44 (0)20 7594 1518g.collins Website

 
 
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Location

 

4.83Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Collins:2017:10.1111/maps.12873,
author = {Collins, GS and Lynch, E and McAdam, R and Davison, TM},
doi = {10.1111/maps.12873},
journal = {Meteoritics & Planetary Science},
pages = {1542--1560},
title = {A numerical assessment of simple airblast models of impact airbursts},
url = {http://dx.doi.org/10.1111/maps.12873},
volume = {52},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Asteroids and comets 10–100 m in size that collide with Earth disrupt dramatically in the atmosphere with an explosive transfer of energy, caused by extreme air drag. Such airbursts produce a strong blastwave that radiates from the meteoroid's trajectory and can cause damage on the surface. An established technique for predicting airburst blastwave damage is to treat the airburst as a static source of energy and to extrapolate empirical results of nuclear explosion tests using an energy-based scaling approach. Here we compare this approach to two more complex models using the iSALE shock physics code. We consider a moving-source airburst model where the meteoroid's energy is partitioned as two-thirds internal energy and one-third kinetic energy at the burst altitude, and a model in which energy is deposited into the atmosphere along the meteoroid's trajectory based on the pancake model of meteoroid disruption. To justify use of the pancake model, we show that it provides a good fit to the inferred energy release of the 2013 Chelyabinsk fireball. Predicted overpressures from all three models are broadly consistent at radial distances from ground zero that exceed three times the burst height. At smaller radial distances, the moving-source model predicts overpressures two times greater than the static-source model, whereas the cylindrical line-source model based on the pancake model predicts overpressures two times lower than the static-source model. Given other uncertainties associated with airblast damage predictions, the static-source approach provides an adequate approximation of the azimuthally averaged airblast for probabilistic hazard assessment.
AU - Collins,GS
AU - Lynch,E
AU - McAdam,R
AU - Davison,TM
DO - 10.1111/maps.12873
EP - 1560
PY - 2017///
SN - 1086-9379
SP - 1542
TI - A numerical assessment of simple airblast models of impact airbursts
T2 - Meteoritics & Planetary Science
UR - http://dx.doi.org/10.1111/maps.12873
UR - http://hdl.handle.net/10044/1/45588
VL - 52
ER -