5.5 Ml Water In Hydrate Experiment

The results of 7 mL water from the front camera in the experiment type 1 is shown in Figure 17. These results were also analyzed with the three different points on the time scale in the same way as the case of 5.5 mL water: that is, the first point (A), the second one (B) and the third one (C). According to the three points, the graphs from PIV analysis are as well listed with the averaged velocities for 60 frames (30 seconds) and the black vector for only one pair of the frames. A release of CO2 and onset of the hydrate can be seen in the third row (C). The hydrate often grew fast in a few frames while it sometimes grew slowly over the frames after the hydrate formed. This is because the hydrate formation is a stochastic process as mentioned in chapter 2.3.2.
It also means that the rate of the convection decreases. In contrast with the graph of 5.5 mL water in Figure 14, the velocity at the instant of the hydrate formation does not slightly increase but still decreases in the 7 mL water. It would be caused by the random process of the formation. If the time for the hydrate production is short, the hydrate starts to form in a thin layer of the interface between the liquid CO2 and water phases and it slowly grows through the bulk of the water. This happens if the hydrate decided to grow before CO2 is homogenously distributed in the bulk of the water. It takes some time for CO2 to be well distributed and therefore achieved for a zero-velocity level. As seen in Figure 14 at the second point (B), the water was calm. It would indicate that CO2 was well distributed so the hydrate had a fast growth in the bulk of the water. The fast growth of the hydrate may produce a peak of velocity of the tracers in the instant of the formation as shown in Figure 14 at the third point