Is a settling drop equivalent to a rising bubble? The answer is known to be in general a no, but we show that when the density of the drop is less than 1.2 times that of the surrounding fluid, an equivalent bubble can be designed for small inertia and large surface tension. Hadamard's exact solution is shown to be better for this than making the Boussinesq approximation. Scaling relationships a...

Abstract The phenomenon of rising bubbles in pure water is an important aspect the bubble and liquid interactions. Due to several forces that act on accompanied by pressures inside outside bubble, behaviour may vary depending a few parameters such as characteristics medium. In general, increase occurs following drag motion determined coefficient but under certain conditions also move rolling pa...