Experimental determination of drag coefficient for volcanic materials: Calibration and application of a model to Popocatépetl volcano (Mexico) ballistic projectiles
Article first published online: 3 JUN 2006
Copyright 2006 by the American Geophysical Union.
Geophysical Research Letters
Volume 33, Issue 11, June 2006
How to Cite
2006), Experimental determination of drag coefficient for volcanic materials: Calibration and application of a model to Popocatépetl volcano (Mexico) ballistic projectiles, Geophys. Res. Lett., 33, L11302, doi:10.1029/2006GL026195., and (
- Issue published online: 3 JUN 2006
- Article first published online: 3 JUN 2006
- Manuscript Accepted: 11 APR 2006
- Manuscript Revised: 7 APR 2006
- Manuscript Received: 2 MAR 2006
 This study shows the results of experiments performed in a subsonic wind tunnel to measure drag coefficients (Cd) for volcanic particles emitted by Popocatépetl volcano (Mexico). The results indicate that volcanic projectiles move in a range of Reynolds number (Re) values where Cd is independent of Re. Drag coefficients of volcanic fragments were found between the values of spheres and cubes with low values. In this study, initial conditions of the ballistic equations were calibrated with the “launching” kinetic energy from ballistics expelled by Popocatépetl volcano during the eruptive event of December 17, 1998. The maximum range of the projectiles calculated with the experimentally measured drag coefficient is in better agreement with the field and observational data reported here than using the values of geometrical bodies as in previous studies. Our study can be useful for definition of safety zones around volcanoes to protect people and infrastructure adequately.