Ballistic Ducks and the Inclined Explosions – UEA Open Day Part 1 and 2

What’s up with all the ducks? July 4th Update! 

Fantastically nerve free rapid-shooting from ENV Undergrad  Esmee Thornton shows up the brilliantly different behaviour of the ducks vs the balls. We’re hoping to shoot a movie to shed more light on this tomorrow at the Planet Earth Summer School.

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 Here’s our new duck distribution map. This time we ran the explosions on more even ground.  The blue and green dots are the new 4th of July Faculty and Graduate ducks! 
    
 

Across the four UEA Open Days, the UEA Volcanology Team will be performing around 25 separate ‘bin bangs’ or explosions generated by liquid nitrogen in a simulated Vulcanian-style eruption.

The explosion is created by the failure of a well known Fizzy drinks bottle as iiquid nitrogen turns to gas. The explosion drives the water and balls upwards to simulate an explosion
Starting with a barrel of water, the explosion is created by the failure of a well known Fizzy drinks bottle as iiquid nitrogen turns to gas. The explosion drives the water and balls upwards to simulate an explosion

This seems like too good an opportunity to miss; so we thought we’d turn them into ‘repeat’ experiments! We’ve investigated how to vary explosion size before so this time we thought we’d look at the ballistics.

These are denser particles in an eruption, which behave as projectiles. Their behaviour depends on launch angle, velocity and their drag (retardation of movement by air resistance). We’re in fine company too, some of  the original work on ballstics was done by Gallileo and Euler.

We want to test the hypothesis that if we have   distinctive particle types, they would behave in distinctive ways and over time we could begin to predict which would travel further.

Enter the ducks!

Our ballistic ducks! They represent three things about the University. The heavier 'Faculty' Ducks: Health;Humanities, Social Sciences and Sciences. The dignified Graduate Ducks and the little light bunny ducks!
Our ballistic ducks! They represent three great things about UEA. The heavier ‘Faculty’ Ducks: Health;Humanities, Social Sciences and Sciences. The dignified Graduate Ducks and the little light bunny ducks!

So we set off a few of these:

Great #ueaopenday today we were setting off bin bangs all day! Science in action! #heyuea #universityofeastanglia #norwich #opendays

A post shared by University of East Anglia UEA (@uniofeastanglia) on

and then plotted the particles on a map (red for Faculty ducks, orange for bunnies, yellow for graduates).

The clearest result here is the influence of the slightly (north-south) inclined surface we ‘erupted’ our volcano on. This is not without a natural analogue, our colleague on the STREVA Project (Paul Cole) has  has published a paper on his observations of inclined explosions and the consequences for particle distribution and hazards (although in this case an inclined crater not an inclined conduit). There is just a hint that as our experiments got rumbunctiously a wee bit larger the effect of the slope was less important (wider dispersal of later ducks!).

A real 'inclined' explosion, Soufriere Hills Volcano, Montserrat on 8th December 2008, from Cole et al., 2014.
A real ‘inclined’ explosion, Soufriere Hills Volcano, Montserrat on 5th December 2008, from Cole et al., 2014.

Subtle differences in take-off angle, and particle interference mean that each individual particle is going to struggle to behave as the perfect trajectory each time. But with repeat experiments, if they were very different we would expect differences to emerge in the overall pattern.

To add further spice, and as a mark of respect for UEA’s interest in citizen science we are asking people who watch to take just one ball and ‘predict’ the type of furthest travelled duck.

The results of the 'citizen' predictions. The early strong showing from 'Faculty' meant they edged it with 37 votes. They were our furthest travelled ducks on 20th June.
The results of the ‘citizen’ predictions. The early strong showing from ‘Faculty’ meant they edged it with 37 votes. They were indeed our furthest travelled ducks on 20th June.

They’ve got our plot of ‘past behaviour’, my patter about the duck ‘properties’ and their own instinct (or scientific knowledge!) of what might be important.

We’re off again on Saturday the 4th of July. To celebrate our UEA-USA connections (Faculty, students and great connections with several Universities on our Year Abroad Programs) we’ll be using red, white and blue balls as well as ducks!


 

What’s up with all the ducks? July 4th Update! 

Fantastically nerve free rapid-shooting from ENV Undergrad  Esmee Thornton shows up the brilliantly different behaviour of the ducks vs the balls. We’re hoping to shoot a movie to shed more light on this tomorrow at the Planet Earth Summer School.

This slideshow requires JavaScript.

 Here’s our new duck distribution map. This time we ran the explosions on more even ground.  The blue and green dots are the new 4th of July Faculty and Graduate ducks! 
    
 

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