Experimental and Numerical Investigation of Strength of Inertial Entrainment

Abstract

Entrainment process can be seen both in natural and artificial events. Cyclonic winds and weather storms include stratified layer of air and water phases. Many turbulent weather conditions can be explained on the basis of entrainment. Different artificial purposes also utilize the phenomenon of entrainment. One of the examples is an educator pump. These pumps are used in ships to extract water in case of water leakage into the ship. The pump is used to remove the air and the water inside the ship is entrained out by the suction of the pump. Entrainment is used for air bubble entrapment in concrete. This helps to strengthen the concrete. Entrainment is also observed in the making of emulsion of one fluid in another, such as margarine. As for artificial processes with stratified liquid layers, the best examples metal extraction industries and nuclear reactors. In both cases gases are formed within liquid layers and cause entrainment. This is unwanted as entrainment causes mixing between two liquids. However in case of desalination plants and other places where mixing is desired, entrainment is enhanced purposely. The mixing of two fluids is generally done by bubbling gas through a tank containing the two fluids. These type of systems are called gas bubble stirred tanks.