1. Steam condenses in the tube, this flows down into the flask
Pressure in the flask is decreased
Boiling temperature is decreased
Amount if boiling is increased
The steam is at a higher temperature than the tube which causes the steam to condense and flow down into the flask
Because water has a lower density than steam the pressure in the flask is decreased and the boiling temperature decreases
Therefore the amount of boiling increases.
The increased boiling rate causes the pressure in the flask to increase which also increases the
Pressure is increased
Boiling slows rapidly

2. Decreasing pressure below atmospheric
Water is pushed down the tube from the catch basin
Temperature in the flask is decreased
Period of quiet while system regains heat energy
Eruption begins again
Because the pressure acting on the water in the catch basin than the pressure inside the flask, the water from the catch basin is forced down the tube into the flask
This water is at a lower temperature as it was losing heat energy while in the catch basin
because of this the temperature of the water in the flask is decreased
The loss of heat energy means the system cannot continue erupting and a period of quite follows while the system regains the lost heat energy
When the temperature is high enough, the cycle starts again
Steam generates and so on

3. “Time Dependence” What we Measured Time Between Eruptions
Length of Eruptions
How it Could Change
Longer or Shorter
More or Less Variable
The question asked us to investigate the time dependence of the eruption process.
We chose to separate Time Between Eruptions and Eruption Length because I thought one of the variables I test might affect one of these times but not the other and this was an affect I thought might be significant.

4. 1. Tube Length Length of Tube in Flask Control Variables Tube diameter
Internal 4mm
Total 6mm
Height Above Heat
120mm
Water in Catch Basin
To Ring
Length of Tube in Flask
25mm
Explain what changed in each test and that the length of tube in flask was kept the same (2.5mm)

5. This graph shows a shallow downwards trend – this means the length of eruptions gets shorter as tube length gets
For the longer tube there is more water in the catch basin therefore there is greater hydrostatic pressure which means the pressure in the flask doesn’t have to drop as much before the water in the catch basin is pushed down the tube.
It also shows a large decrease in variation of eruption length as the tube length increases.
Because of the shape of the catch basin (funnel) a small difference in the water volume with a short tube has a greater effect on the surface area of the water in the catch basin.

6. I expected the longer tube lengths would result in a longer time between eruptions however this graph showed no clear pattern
I have no explanation for this currently and so would have to collect more data to give a conclusive answer

7. 2. Length of Tube in Flask Control Variables Tube diameter
Internal 4mm
Total 6mm
Height Above Heat
120mm
Water in Catch Basin
To Ring
Tube Length
524mm
Explain what I changed in each test and that the length of tube was kept the same (524mm)

8. This graph shows a clear upwards trend
This graph shows a clear upwards trend. Time between eruptions increased as the length of tube in the flask increased
Explanation/Interpretation
More water in the system so more water at top
More surface area at top so more heat energy lost
More water to be reheated to boiling temperature before next eruptions
The length with the most variation is 2.5 which was the length used in tube length test.
Could have contributed to the high level of variation in previous graphs.
Data points are relatively close together with few outliers

9. Just like in the previous graph there is an upwards trend
Just like in the previous graph there is an upwards trend. When the length of tube in the flask is increased the eruption length increases also
Explanation/Interpretation
More water is moved around the system

10. Conclusions Tube Length
Tube length may have an affect on time between eruptions but more data is needed before this could be determined
Eruption length gets shorter as tube length gets longer
Length of Tube in Flask
Time between eruptions increased as the length of tube in the flask increased
The eruption length increases when the length of tube in the flask is increased

11. References
Geyser Model with Real Time Data Collection – By Samo Lasic & Gorazd Planinsic from the University of Ljubljana, Slovenia

12. Thanks to… Britney Kerr Jamie Simonsen Mac Karalus David Sturrock
Drew McGlashen
Melanie Hunter