particle aggregation afshan shaikh eas 4480 spring 2012 april 26, 2012
TRANSCRIPT
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Particle Aggregation
Afshan ShaikhEAS 4480Spring 2012April 26, 2012
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Importance
•Ash plumes of explosive volcanism can reach upper atmosphere
•Ash plume travel distance dependent on ash aggregation ▫Also case for volcanic vents▫Pyroclastic density currents
•Better understanding of eruptive flows •Help predict after math of volcanic
eruptions
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http://www.boston.com/bigpicture/2011/06/volcano_erupts_in_chile.html
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http://www.boston.com/bigpicture/2011/06/volcano_erupts_in_chile.html
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Methods• First experiment (referred
to as ‘old data’ later’)▫ Laser sheet▫ Data processed by matlab▫ Ash and Ballontini
• Second experiment ▫ Evacuate to simulate
lower pressures▫ Hand processed (yay)
Old experiment set up, Image obtained from Jen Telling
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Formulas and Assumptions
•CKE ( Collisional Kinetic Energy)▫Calculated differently for both experiments▫Energy of the collision
•Assumed densities of the ash was 2650 kg/m3
•Perfect sphere for volume calculation •Diameter
▫Reduced Diameter vs. Assumed Diameter •Aggregation Efficiency calculation
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Analysis
•Used Regression analysis (RH and CKE)▫For linear regression, error structures
calculated and plotted (RH)•Correlation Coefficient (RH and CKE)•Boot Strap for Correlation Coefficients
(RH and CKE)•Comparison of actual vs. bootstrap mean
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Boot Strap Correlation Coefficients (CKE)
CorrCoefR = -0.7858P = .0
BootStrap R = 0.7972
CorrCoefR = -0.5659P = .005
BootStrap R = 0.609
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Boot Strap Correlation Coefficient (RH)
CorrCoefR = 0.0837P = .5892
BootStrap R = 0.0807
CorrCoefR = -.2704P = ..4499
BootStrap R = -0.2798
CorrCoefR = -.2290P = .0.3936
BootStrap R = -0.2461
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Conclusion
• No significant correlation between RH and Aggregation Efficiency
• Definite nonlinear regression Aggregation Efficiency and CKE