Detonation propagation through an interface is being studied at Caltech. In these
experiments, the interface shape is determined by the gravity currents. This report
presents an experimental study of the formation and the development of these
gravity currents by an analog system in a water channel using water and salt water to
simulate the density differences in detonation experiments. The major parameters
such as the Reynolds number and the density difference were matched in both
experiments to be able to compare the gravity current in the water channel and the
gravity current in the Galcit detonation tube. In the present study, the gravity current
was generated by the removal of a plate, and was visualized by adding food dye. The
results confirm previous studies; Keulegan demonstrated in 1957 that the velocity of
the gravity current is a function of the square root of the density difference. The
interface is affect by the retracting of the plate which creates the wake effects. The
Kelvin-Helmholtz instabilities on the upstream side of the gravity current create the
visualized mixing zones. Finally, this study revealed how the gravity current interface
into the Galcit detonation tube should develop and where the mixing zones should
occur