Plinian Cloud Results


	The ultimate website for understanding granular flows

The Granular Volcano Group
Plinian Cloud Simulation Page

[Ascending eruption cloud from Redoubt Volcano and its reflection in the waters of Cook Inlet.
View is to the west from the Kenai Peninsula. Photograph by J. Warren, April 21, 1990.]

Hello,

Be welcomed here !

This page is entirely devoted to plinian cloud simulations. For practical reasons, all the results, their analysis, interpretations, discussions and conclusions are presented within a Microsoft Power Point Presentation in HTML format. In this slide show, we review the basic properties of multiphase and granular flows, the computer codes we use, the basic properties of plinian clouds, and some of the results we have achieved.

The results presented herewith focused mostly on the validation aspect as we compare with real observations and well-known facts of plinian cloud dynamics. We also discuss the grid independence of our codes.

If you wonder who is behind those simulations and this project, please, visit also my bio page.

If you need an official reference for the content of this website, please, use:
Dartevelle, S., Numerical and granulometric approaches to geophysical granular flows, Ph.D. thesis, Michigan Technological University, Department of Geological and Mining Engineering, Houghton, Michigan, July 2003.

For now, you may either scan through the slide show, upload a series of snapshots showing the development of three different plinian clouds over one hour, or access to each animation movie separately.

HTML Power Point Slide-Show of Plinian Cloud simulation modeled with (G)MFIX computer codes:

[Plinian Cloud Diaporama]

(you need a Browser that can deal with frames.
This Diaporama quiet frankly only works well with Ms. Explorer -sorry for this-)

Or just download the same diaporama in two Microsoft pps diaporama files:

[Plinian Cloud Diaporama Part 1 and 2]
Introduction
What is a granular flow? What is a plinian cloud?
Three plinian cloud simulations

[Plinian Cloud Diaporama Part 3,4 and 5]
Analysis and Discussion
Validation studies
Conclusions and Where are we heading for

Time sequence snapshots over one hour of three plinian cloud simulations:

[time_sequence_color_RGB.jpg]

(250 Kb)

Animation movie over 1 hour of a weak Plinian column (named Plinian_1, grain concentration).
Size (radial x height): 20km x 18km, resolution: 30m and variable x 30m
Mass Flux is 3.15x10⁶ kg/s (this is a small mass flux)

[click here]

(1185 Kb)

Animation movie over 1 hour of a mid-size Plinian column (named Plinian_2, grain concentration).
Size (radial x height): 40km x 25km, resolution: 50m and variable x 50m
Mass Flux is 2.41x10⁷ kg/s (this is an mild mass flux)

[click here]

(894 Kb)

Animation movie over 1 hour of a strong Plinian column (named Plinian_3, grain concentration).
Size (radial x height): 60km x 36km, resolution: 80m and variable x 80m
Mass Flux is 1.39x10⁸ kg/s (this is getting a strong mass flux)

[click here]

(883 Kb)

Animation movie over 1 hour of the Temperature anomalies within a strong Plinian cloud (Plinian_3, Temperature difference with the ambient).
Size (radial x height): 60km x 36km, resolution: 80m and variable x 80m
Mass Flux is 1.39x10⁸ kg/s

[click here]

(894 Kb)

Animation movie over 1 hour of the Temperature anomalies within a middle Plinian cloud (Plinian_2, Temperature difference with the ambient).
Size (radial x height): 40km x 25km, resolution: 50m and variable x 50m
Mass Flux is 2.41x10⁷ kg/s

[click here]

(859 Kb)

Please, let enough time to your Browser to upload the animations (about 10 to 20 seconds).
If you wanna see those movies without no trouble, please, use the latest version of Microsoft Windows Media Player, RealAudio Player One, and/or QuickTime Player which can be all downloaded for free.

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If you wish more details about the governing equations, the physics, so forth … Please feel free to contact the Web Master or to ask any question you want in our granular-volcano Discussion Forum.

The computer codes used for all the simulations seen on this page is (G)MFIX ((Geophysical) Multiphase Flow with Interphase eXchange). MFIX is developed by the National Energy Technology Laboratory (NETL), division of the U.S. Department of Energy (DOE). For more information on the MFIX project, please, visit the MFIX page.

You can also visit the Granular Theory Overview Page where you will find some key facts to understand those results. If you do not know anything about granular flow and multi-phase flow, I advise you to stop by in our What is a Granular Medium Page. In case viscous stress is nothing but Chinese for you, then don’t panic, and go instead in our All I wanna know ’bout Viscous Stress Page. For a more detailed review of the frictional stress studied from the plastic flow theories using the Mohr-Coulomb law, please visit our A Review of the Plastic-Frictional Stress - Part. 1.

Please, don’t forget to sign our Granular Volcano Guest Book.